Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank

Anthony Karani; Andrew Gichira; Tobin Musembi; Lucy Adhiambo; Victor Otieno; Jonathan Jenkins

doi:doi:10.11648/j.jps.20261402.12

Research Article |

| Peer-Reviewed

Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank

Anthony Karani^*

, Andrew Gichira

, Tobin Musembi

, Lucy Adhiambo

, Victor Otieno

, Jonathan Jenkins

Published in Journal of Plant Sciences (Volume 14, Issue 2)

Received: 5 February 2026 Accepted: 27 February 2026 Published: 26 March 2026

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Abstract

Ecological restoration partially relies on plant regeneration from the above-ground vegetation (AGV) and soil seed banks (SSB); however, the co-occurrence of species in these sources vary across ecosystems. In this study, we measured soil properties and surveyed SSB and AGV, monitored regenerants for two years to estimate survival rates. We assessed the variation of species abundance in AGV, SSB and natural regenerants using a log-linear model and tested for correlation between soil properties using Pearson’s correlation coefficient and the association between the importance value index and survival rate of regenerants using generalised linear models. We found within-community dissimilarity between AGV and SSB, and the co-occurrence of species was predicted by periods of invasive species removal. There were five (4.46%) common species and five (4.46%), 34 (30.36%) and 42 (37.5%) exclusive species in natural regenerants, SSB and AGV, respectively. The common species among all periods of invasive species removal were 12.5%, 20%, and 41.7% in AGV, natural regenerants, and SSB, respectively. The diversity of SSB was positively associated with the survival rate of regenerants, but not AGV diversity. Survival rates of regenerants were associated with seed mass but not plant height, while plant functional traits were not associated with importance value indices of AGV. These findings show that native plant recovery can be accelerated by removal of invasive species; however, diversity differences exist between AGV and SSB, which were not necessarily modulated by plant functional traits and soil characteristics.

Published in	Journal of Plant Sciences (Volume 14, Issue 2)
DOI	10.11648/j.jps.20261402.12
Page(s)	79-92
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2026. Published by Science Publishing Group

Keywords

Afromontane Forest, Ecosystem Recovery, Ecosystem Restoration, Invasive Species, Natural Regenerants, Soil Seed Bank

1. Introduction

Ecological restoration is one of the most critical solutions-based approach for halting biodiversity loss, promoting human well-being, and mitigating environmental changes

[17, 41]

. Besides returning ecosystems to their natural state, ecological restoration aims to promote functional roles and ecological processes that allow ecosystems to achieve community succession

[42, 46]

. Recent studies have focused on understanding how restored forests and landscapes recover from the effects of environmental degradation through natural regeneration and survival of propagules that are preserved in the soil and those available from other sources and the integration of dispersal agents

[25]

. Soil seed bank, seedling survival, and plant functional traits are important for the succession and resilience of forest ecosystems

[36, 39]

. The resilience of native and restored ecosystems is, however, threatened by limited natural regeneration of native plant species due to the colonisation of invasive alien species

[44]

. The effects of invasive species on local ecosystems are compounded with climate variability, habitat transformation, pollution, and unsustainable harvest of biological resources

[37]

. Invasive species affect seed germination, exacerbate seedling mortality rates, suppress above-ground diversity, and pose a threat to birds and insects

[13, 27]

The removal of invasive species is gaining momentum as an intervention for enhancing natural regeneration and as a strategy to restore degraded ecosystems

[62, 66]

. Studies have shown that removal of invasive species improves restoration outcomes, even with land-use histories

[10, 20, 23, 58]

. Effective recovery of degraded ecosystems requires habitat-specific management strategies for invasive species, as removal alone may not guarantee successful natural regeneration

[13, 61]

. The co-occurrence of multiple invasive species compounds the impact on local ecosystems, exhibiting variable interactions with native species, altering habitats and disrupting ecological processes

[6, 22, 28]

. Additionally, invasions influence both biotic processes and abiotic components, including soil chemical composition and water quality

[16, 60]

. Soil properties are important when studying the SSB because they directly influence seed viability, germination and species composition. The soil texture and water content affect seed burial depth, light penetration and seedling emergence, while soil pH and nutrients shape which species can survive in AGV, thus guiding restoration and ecosystem dynamics

[23, 60]

. Plant functional traits such as growth form, plant height, life form, fruit type, seed mass, deciduousness, and dispersal syndrome have been used to understand succession in restored forests

[20, 22, 25, 46]

A number of invasive species pose significant threats to ecosystems in East Africa

[30, 64]

. In the Afromontane forests (isolated high-attitude regions of the Afrotropical realm), key invaders include the woolly nightshade (Solanum mauritianum Scopoli) and orange jessamine (Cestrum aurantiacum Lindley), both Solanaceae shrubs that originated from the Neotropics, where S. mauritianum is native to Brazil, while C. aurantiacum is native to Central and South America. In Kenya, C. aurantiacum has been reported in multiple forest ecosystems, including Cherangani Hills, Mount Elgon and the Central Highlands, causing adverse effects on the health and vitality of native ecosystems

[25, 30]

. At Brackenhurst Botanical Garden and Forest (BBGF), both species were introduced, where they regenerate prolifically, forming dense understory thickets that suppress native species recruitment and alter forest structure

[30, 38]

. Their management is a conservation priority because Afromontane forests have unique flora and fauna assemblages and play a pivotal role in the provisioning of ecosystem services and safeguarding the local livelihoods

[25, 35, 55]

. Additionally, Afromontane ecosystems have faced substantial degradation due to increased human population, land conversion for agricultural expansion and climate stochasticity

[5, 64]

The need to adopt best practices in ecological restoration that not only reverse degradation but also foster resilience to ongoing environmental changes and growing human population pressure has gained global acceptance

[49, 51]

. There is limited information, however, on the effects of invasive species on AGV, forest regeneration, survival of regenerating seedlings, and SSB composition in the context of ecological restoration. The main objective of this study is to evaluate how plant community composition of AGV and SSB, diversity, and regenerant survival are influenced by the removal of two invasive alien species, S. mauritianum and C. aurantiacum in relation to soil properties and plant functional traits. This study addresses the following questions: how does species diversity in above-ground vegetation and the soil seed bank vary across different invasive species removal treatments? Which soil properties are most strongly associated with the composition of vegetation and soil seed bank communities? Do plant functional traits and species importance value indices, influence the survival rates of regenerating plants?

2. Material and Methods

2.1. Study Area

We conducted this study at Brackenhurst Botanical Garden and Forest (BBGF), located in the Central Highlands of Kenya (K4 Floristic Region) at Tigoni, Limuru, about 25 km north of Nairobi (Figure 1). The forest represents an Afromontane ecosystem undergoing ecological restoration, established as an indigenous forest starting in the year 2000 on land previously utilised for plantations of exotic species such as Mexican cypress (Hesperocyparis lusitanica (Mill.) Bartel), wattle bark (Acacia mearnsii De Wild.), blue gum (Eucalyptus globulus Labill.) and Australian blackwood (Acacia melanoxylon R. Br.)

[38, 51, 52]

. The forest is ecologically isolated from the southernmost points of the Aberdare Ranges (Figure 1). The transition zone between BBGF and the forest blocks is characterised by tea plantations, exotic tree plantations, other agricultural uses, and human settlements

[51]

. The forest lies 5.36 km south of Uplands Forest and 15.02 km south of Kireita Forest, whose native flora has been detailed by Kipkoech et al.

[26]

, and a natural vegetation of a tropical montane forest which is optimal for a native reference ecosystem (for BBGF restored forest) recommended by Toma et al.

[56]

. The site lies at an elevation of 2144 m - 2194 m above sea level, with an average annual temperature of 17°C and mean annual rainfall of 900 mm.

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Figure 1. Map of Kiambu County, showing sampling sites at the Brackenhurst Botanical Garden and Forest (BBGF) in Tigoni, Central Highlands of Kenya. Inset is the map of Kenya.

2.2. Above-ground Vegetation and Regenerants Survival

We identified sampling sites based on the time since removal of invasive species at the time of designing this study. Various sections of the forest had been cleared of invasive species six months’ prior (July 2022), while others had been unmanaged for 6 years (2016), 2 years (2020), and 1 year (2021). Removal of invasive species was not consistent in the years preceding COVID-19 due to funding gaps, and therefore we excluded these sites from the study. Further, the heterogeneity in the timing of invasive species removal presented an opportunity to investigate the functioning of the restored forest under varying levels of invasive-native species co-occurrence. We established ten plots (20 m x 10 m) and surveyed for above-ground vegetation composition, plant density, invasive cover, and crown cover. For shrubs and mature trees, we recorded species identity and diameter at breast height (DBH). Additionally, we randomly placed 10 1-metre squared quadrats in each plot, which we used to survey herbaceous seedlings (height = <0.5 cm) and saplings (height = >0.5 cm but less than 2 cm) as defined by Dyderski & Jagodziński

[13]

(a total of 100 nested plots). In addition, we recorded data on plant height and root collar diameter (RCD) of seedlings and saplings. Identification of species recorded was done by an experienced taxonomist based on Vascular Flora of Kenya

[67]

. We collected these data once at the beginning of the study due to resource and time constraints.

We identified and tagged the naturally occurring seedlings and saplings (regenerants) in each plot. In order to estimate their survival rate and recruitment, we monitored these regenerants over a period of two years, between 2022 and 2024 during the dry season (February-March), long rains (May-July), and short rains (October-November), and incorporated new recruits. Additionally, we retrieved species functional traits from the Global Inventory of Floras and Traits (GIFT) database using the guidelines outlined in Weigelt et al.

[63]

and Denelle et al.

[11]

. The following traits were selected: growth form, plant height, life form, fruit type, seed mass, deciduousness, and dispersal syndrome.

2.3. Soil Chemical Properties

We sampled soils at five points in each plot (one at each corner and one at the centre), and soils were drawn using a soil auger up to a depth of 30 cm. The five samples were thoroughly mixed, and a composite sample weighing approximately 200 g was drawn from the mixture, packed in a Ziploc bag, and transported to the laboratory of the Kenya Agricultural and Livestock Research Institute (KARLO) for processing and analysis. Diverse methods used at the facility are detailed by Ashiono et al.

[3]

. Soil properties that were tested for include total phosphorus (P), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), total organic carbon, total nitrogen (N), manganese (Mn), soil pH, exchangeable acidity, iron (Fe), zinc (Zn), and copper (Cu).

2.4. Soil Seed Bank

We sampled soils using a garden trowel to a depth of 0–10 cm from five (10 x 15 cm) subplots positioned at the four corners and centre of each plot. Soil samples were placed in plastic ziplock bags and transported immediately to the greenhouse for germination tests. In the greenhouse, each soil sample was placed into an individual sterile potting bag measuring 7 cm × 12 cm × 12 cm, pre-filled with sterilised sand. The soil under investigation occupied about 2 cm of the top layer. The use of a neutral, well-draining germination medium was preferred because it minimises nutrient variation and pathogen interference, simulating near-natural conditions while maintaining controlled testing conditions. The potting bags were arranged in rows under ambient light within a greenhouse, while ambient temperature and humidity were monitored using an Elitech GSP-6 data logger (™ Elitech Technology, Inc., CA, U.S.A.). Germination tests were carried out according to the International Seed Testing Association (ISTA) rules and guidelines of the Society for Ecological Restoration (SER) as detailed in ISTA

[21]

and Pedrini & Dixon

[41]

. Germination trials followed the cultivation method used by Plohák et al.

[43]

and Fabšičová et al.

[15]

The emerging seedlings were identified, counted and recorded until there was no further emergence following the procedure used by Sanou et al.

[50]

. Seedlings were identified to species level by an experienced botanist using the keys provided by Kipkoech et al.

[26]

and Zhou et al.

[67]

and references therein. To assess the viability of any non-germinated seeds, we extracted the seeds as described by Plohák et al.

[43]

and performed a cut test at the end of the germination period, which helped to distinguish between viable and non-viable seeds. Out of 772 seeds that were tested, 93 (15.34%) were non-viable and therefore excluded from the analysis.

2.5. Data Analysis

We estimated the diversity of the AGV and SSB using the Shannon-Weiner index. The Shannon entropy is estimated using this formula:

H = - \sum_{i = 1}^{k} P_{i} * {In P}_{i}

Where H is the diversity index, ∑ is the total number of species, pi is the proportion of individuals belonging to the i^th species, and ln is the natural logarithm. This index provides a measure of diversity that considers both the number of species (richness) and their relative abundances (species evenness). In order to calculate the importance value index (IVI) for each species of the AGV, the relative frequency (RF), relative density (RD), and relative dominance (RDO) were calculated. To achieve consistency, we used DBH for trees, RCD for seedlings and saplings and multiplied each with its height before calculating dominance. The IVI is estimated using this formula:

IVI =Relativedensity + Relative frequency + Relative dominance

We performed all statistical analyses in R

[45]

. We estimated within-community dissimilarity using Rao's Q index, a measure that calculates the weighted sum of pairwise dissimilarities between all species within a community, where dissimilarities are weighted by the product of the species' relative abundances

[47]

. The Rao’s Q is estimated using this formula:

Q = - \sum_{i = 1}^{s} \sum_{j = 1}^{s} d_{ij} * p_{i} p_{j}

Where: p_i and p_j represent the relative abundances of species i and j in the community, and d_ij is the dissimilarity between species i and j.

We calculated dissimilarity and diversity indices in the vegan package in R developed by Oksanen et al.

[40]

. Further, we performed Canonical Correspondence Analysis (CCA) using the vegan package and visualised the relationships among species composition, sampling sites, and soil properties in an ordination plot. We established the correlations between soil chemical properties using Pearson’s correlation coefficient. We fitted generalised linear models (GLM) with an identity link function, where survival rate was modelled as a response variable while seed mass and plant height were fixed effects. This was done separately while incorporating growth form, fruit type, deciduousness, and dispersal syndrome to account for group-level variability. This was repeated using the importance value index as the response variable. Variation in species abundance among AGV, SSB and regenerants survival was assessed using a log-linear model, and a likelihood ratio test (LRT) was used to compare two GLMs with a Poisson error distribution and log link function, where the null model was fitted for independent effects of species and site, and the alternative model included an interaction term. Common and exclusive species in AGV, SSB and regenerants, and also separately for time since removal of invasive species in each community, were visualised using a VennDiagram package.

3. Results

We recorded 71 species in the AGV, belonging to 63 genera and 34 families in the AGV. The most species-rich families were Rubiaceae (9.9%), Euphorbiaceae (8.5%) and Fabaceae (5.6%). Their growth forms included trees (66.2%), shrubs (31.0%), herbs (1.4%) and lianas (1.4%). Species with the highest importance value index were Albizia gummifera (J. F. Gmel.) C. A. Sm., Prunus africana (Hook.f.) Kalkman, Vitex keniensis Turrill, Cestrum aurantiacum, Polyscias fulva (Hiern) Harms, Croton macrostachyus Hochst. ex Delile, Ehretia cymosa Thonn., Millettia dura Dunn, Syzygium guineense Wallich, Solanum mauritianum, Markhamia lutea (Benth.) K. Schum., and Tabernaemontana stapfiana Britten. A total of 4033 seedlings germinated from the SSB. These plants belonged to 47 species, 24 families and 38 genera. Their growth forms included 19 herbs (40.4%), 17 shrubs (36.2%), 9 trees (19.1%) and 2 lianas (4.3%). The most species-rich families in SSB were Cannabaceae (23.31%), Solanaceae (17.21%), Rubiaceae (9.72%), Asteraceae (9.03%), Oxalidaceae (7.81%) and Fabaceae (7.76%).

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Figure 2. Bar graph showing plant species and net survival rate, expressed as the change in the number of regenerants across the study period. The zero intercept line represents no net change in abundance (100% survival rate); the positive scale indicates a net increase in the number of regenerants, while the negative scale indicates a net decrease.

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Figure 3. Box plot of different vegetation metrics, showing a) Shannon diversity of soil seed bank, b) Shannon diversity of above-ground vegetation, c) species richness of above-ground vegetation and average survival rate of regenerants. The box represents the interquartile range, the horizontal line is the median, and the whiskers extend to the smallest and largest values.

A total of 842 natural regenerants belonging to 29 species were tagged and monitored through of the study period. Their growth forms included trees (66.7%), shrubs (26.7%) and herbs (6.7%). The number of individuals belonging to 9 (30%) of the species of regenerants that we monitored neither reduced nor increased during the study period (Figure 2). The number of regenerants increased for Maesopsis eminii Engl. (300% increase), Vangueria madagascariensis J. F. Gmel., Ekebergia capensis Sparrm., and Ehretia cymosa Thonn. The species that declined included Senna didymobotrya (Fresen.) Irwin & Barneby (90% decrease), Piper capense L. f., and Calpurnia aurea (Aiton) Benth.

The AGV showed higher average diversity than the SSB for both Rao’s entropy (AGV, 0.83 ± 0.16; SSB, 0.80 ± 0.13) and Shannon entropy (AGV, 2.39 ± 0.69; SSB, 2.28 ± 0.44). We recorded the highest SSB diversity where invasive species had been cleared six years’ prior (H = 2.66), while the lowest was recorded in sites where removal had been done 6 months earlier (H = 1.86, Figure 3). We found the highest AGV diversity in sites with a 1-year removal period (H = 2.92), while the highest AGV richness was recorded in sites with a 2-year removal period. We recorded the highest survival rates of regenerants in sites where invasive species had been removed six months or one year prior. We found no correlation between the AGV diversity and SSB diversity and a negative correlation between invasive cover and canopy cover, leaf litter and SSB diversity. We established a positive correlation between leaf litter and AGV diversity.

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Figure 4. Canonical Correspondence Analysis (CCA) ordination biplot showing the relationship of plant composition (red triangles), sampling sites (blue dots), and soil properties for, (a) above-ground vegetation, and (b) soil seed bank. The arrows point at their respective centroids; the arrow direction indicates the relationship.

We found that soil pH was positively correlated with most of the soil properties, such as N, C, P, K, Ca, Mn and Na. Other notable positive correlations that we found were between pairs of C and N, P and N, P and C, N and Ca, N and Mn, P and K, C and Ca, C and Mn, P and Na, and Mn and Ca. Conversely, we established that exchangeable acidity was negatively correlated with pH, N, C, P, K, Ca, Mn and Cu. Other notable negative correlations that we found were between pairs of Mn and Ca and also P and Mg, while plant survival was correlated negatively with P and K. Plant survival was positively correlated with AGV, and therefore both were positively correlated with Mn and Cu. Vegetation richness was correlated with Zn, while the SSB diversity was positively correlated with Zn and Na. The first two canonical axes (CCA1 and CCA2) in AGV, cumulatively explained 36.8% of the total variation, with individual eigenvalues of 0.527 and 0.492, respectively. The pseudo-canonical correlations were 0.643 and 0.634, respectively. The first four axes cumulatively accounted for 64.2% of the total variation. In SSB, the first two canonical axes) explained 47.4% of the total variation, with individual eigenvalues of 0.495 and 0.277, respectively. The pseudo-canonical correlations for these axes were 0.693 and 0.543, respectively. Cumulatively, the first four axes captured 73.5% of the total variation and 72.4% of the fitted variation. Phosphorus and clearance of invasive species point strongly in the positive direction of Axis 1 and Axis 2 in the AGV (Figure 4a). On the other hand, most soil properties were strongly pointed in the positive direction of Axis 1 and Axis 2 of SSB (Figure 4b).

We found that neither seed mass nor plant height was associated with importance value indices of AGV (Table 1). However, compared to plants with anemochorous seed dispersal (wind), plants with autochorous dispersal showed a significant difference in importance value indices. Seed mass rather than average plant height was associated with plant survival rate. A log-linear analysis revealed that the alternative model (interaction between species and site) fitted the data significantly better than the null model (χ² = 4760.1, df = 220, p < 0.001), indicating site-dependent discordance in species abundance and occurrence. We established that only five (4.46%) species were common in SSB, AGV and natural regenerants, while 30.36% and 37.5% of the species were found exclusively in the AGV and SSB, respectively (Figure 5a). We found only two species (1.79%) were common in natural regenerants and also found in the SSB, while five (4.46%) were neither recorded in the SSB nor AGV survey.

Table 1. Generalised linear model (GLM) results showing the effects of plant height and seed mass on plant survival rate and importance value indices of above-ground vegetation. The table shows estimates, standard errors (SE), p-values, and Akaike’s Information Criteria (AIC). Significant predictors (p < 0.05) are indicated with an asterisk (*).

Traits	Predictor	Importance value index (IVI)					Plant survival rate
Traits	Predictor	Estimate	SE	statistic	pvalue	AIC	Estimate	SE	statistic	pvalue	AIC
Growth form	(Intercept)	7.758	5.14	1.509	0.139	287.32	-0.299	0.56	-0.529	0.603	61.08
	Plant height	0.084	0.10	0.834	0.409		0.002	0.02	0.067	0.948
	Seed mass	-0.443	0.32	-1.377	0.176		1.264	0.44	2.852	0.011*
	Shrub	-5.594	5.30	-1.055	0.298		-0.282	0.69	-0.408	0.688
	Tree	-3.116	5.38	-0.580	0.565		0.345	0.74	0.466	0.647
Fruit type	(Intercept)	-3.656	4.55	-0.804	0.429	195.83	-0.386	0.95	-0.406	0.694	38.40
	Plant height	0.264	0.13	1.977	0.059		0.016	0.03	0.546	0.598
	Seed mass	-0.403	0.39	-1.046	0.305		1.503	0.68	2.224	0.053
	Biotic	6.395	3.45	1.860	0.074		-0.031	0.92	-0.034	0.973
Deciduousness	(Intercept)	6.054	2.43	2.492	0.018*	223.57	-0.496	0.42	-1.183	0.251	60.25
	Plant height	0.133	0.09	1.420	0.166		0.017	0.02	0.989	0.335
	Seed mass	-0.321	0.35	-0.920	0.365		1.354	0.43	3.152	0.005*
	Evergreen	-3.379	2.09	-1.621	0.115		0.186	0.36	0.512	0.615
Seed dispersal	(Intercept)	1.582	3.67	0.431	0.671	181.16	-0.949	0.77	-1.230	0.235	60.12
	Plant height	0.163	0.09	1.703	0.102		0.005	0.02	0.285	0.779
	Seed mass	-0.295	0.33	-0.907	0.374		1.228	0.42	2.923	0.009*
	Autochorous	13.256	4.86	2.730	0.012*		0.179	0.89	0.199	0.845
	Unspecialized	-0.457	6.04	-0.076	0.940		0.379	1.09	0.349	0.732
	Zoochorous	1.409	3.58	0.393	0.698		0.981	0.83	1.183	0.253

Overall, a total of 111 species were recorded, with 71 in AGV, 29 regenerants, and 47 in the SSB. There were nine (12.50%) common species in the AGV, while 13 (18.10%), 7 (9.70%), and 4 (5.60%) were found exclusively in sites with 2-year, 1-year and 6-year periods since removal of invasive species, respectively. Six species (8.30%) were found exclusively in sites where invasive species had been cleared six months prior, while a different set of six species (8.30%) were found exclusively outside these sites (Figure 5b). Afrocanthium keniense (Bullock) Lantz regenerated exclusively in 6-month and 1-year removal periods. There were 6 (20%) common species and 8 (26.7%) that were present in all removal periods with the exception of the 6-month period (Figure 5c). Plant composition of the SSB showed that 20 (41.7%) species were common in all sites, while five (10.4%) were found in all sites except where invasive species had recently been removed (Figure 5d). The rest were found exclusively in sites 2 year removal (14.6%) and a common number of species in 2-year and 6-year sites (12.5%).

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Figure 5. Venn diagram showing common and exclusive species in a) soil seed bank, above-ground vegetation, and regenerants and time since removal of invasive species in b) regenerants, c) soil seed bank, and d) above-ground vegetation.

4. Discussion

Ecological restoration has yielded varied but promising success rates in recent years, with outcomes depending on the ecosystem, restoration methods, and local engagement

[65]

. Restoration work has been ongoing for over two decades at Brackenhurst Forest in the Central Highlands of Kenya, resulting in notable milestones as demonstrated by the substantial diversity of native flora and fauna now present in the restored indigenous forest

[24, 51]

. The results of this study show that pioneer species dominate both the AGV and SSB, which is a significant finding because short-lived, fast-growing species establish rapidly and facilitate the development of tree-related microhabitats that support the eventual colonisation by climax species

[25, 53]

. First, it is due to the functional traits, such as light demand, availability of pre-existing vegetation and land-use histories

[22, 46]

. Second, succession of plant species modulates interactions with other species such as pollinators and seed dispersers

[24, 59]

. Third, pioneer species alter abiotic factors through organic matter that improves soil fertility, bulk density and water retention capability

[1, 20]

The strong correlations reported in the CCA analyses indicate a strong plant-environment associations and reflect the explanatory strength of the selected soil properties. Soil physical and chemical traits shape divergent species assemblages across land‑use types and strongly influence both composition and diversity of SSB and AGV

[19]

. In West African savannas, for example, SSB composition was found to be correlated with soil organic matter, nitrogen, potassium and cation exchange capacity, while AGV was not

[50]

. Through compounding effects, soil properties influence how well soils can store seeds by affecting burial depth, aeration, nutrient availability, and seed persistence

[34, 35]

. Species such as Polyscias fulva (Hiern) Harms, Croton macrostachyus, Macaranga kilimandscharica Pax, and Neoboutonia macrocalyx Pax were recorded in both the SSB and AGV, suggesting that their propagules were either preserved in the soil or sourced from the extant vegetation, as these species grow fast and start producing seeds early. The number of species (47 species) recorded from the SSB in the present study was higher than those recorded from the lowland rainforest (65 species) by Mukhungu et al.

[36]

but lower than the 209 species recorded in Mt Kilimanjaro

[25]

. The SSB represents an archive of seeds that accumulate over time, reflecting adjacent vegetation composition, seed dispersal patterns, and environmental conditions

[5]

. The presence of seeds in the soil, however, does not guarantee their representation in the AGV, as successful germination and establishment are influenced by a range of factors, including interspecific competition, soil properties, and disturbance regimes

[8]

The composition of SSBs often mirrors past vegetation because long-lived seeds can remain dormant for extended periods, which explains the absence of some dominant AGV species in the SSB

[33]

. Such disparities between the AGV and SSB have been associated with anthropogenic disturbances, including overgrazing, firewood collection and other environmental stressors that alter the AGV without corresponding changes in the SSB, thereby limiting natural regeneration

[5, 57]

. In our study, SSB diversity was significantly lower in sites where invasive species had recently been cleared (Figure 3). This finding could also result from other limitations. For instance, invasive species in the present study were removed through uprooting, a technique that can disturb the soil and associated seed reserves. Studies comparing diverse methods, such as removal of flowers and slashing, have shown that natural recovery was higher as compared to uprooting

[12]

. Furthermore, studies have shown that complementing the seedling cultivation method with the seed extraction method enhances species detection in the SSB

[43]

. On a broader scale, this can reflect how anthropogenic activities, compounded with herbivory, seed predation, and dispersal limitations, influence which species establish and persist in restoration sites

[12, 32]

Our study found a positive association between seed mass and plant survival, consistent with findings by Metz et al.

[31]

. As a functional trait, seed mass influences the germination process, seedling vigour and early survival due to various reasons. First, the nutrients, such as starch, proteins, and lipids stored in the endosperm or cotyledons of large seeds, can provide the necessary energy for root and shoot extensions and buffer seedlings against nutrient stress at the onset of photosynthesis

[48]

. Second, these reserves protect seedlings against abiotic stress, such as low soil fertility, making larger seeds more advantageous in resource-limited or competitive environments

[15, 18]

. Third, many species exhibit physiological or morphophysiological dormancy, which delays emergence and acts as a risk-spreading mechanism, allowing seeds to persist in the soil until favourable conditions occur

[9, 29]

. In our study, for example, Ehretia cymosa showed strong regeneration performance despite delayed germination, likely due to a combination of dormancy and seed reserve advantages

[2]

. In contrast, herbaceous and pioneer species tend to allocate resources towards reproduction and colonisation rather than long-term survival, but this means that they require resource-rich environments for successful establishment

[18]

. These species typically produce small, non-dormant or weakly dormant seeds and germinate rapidly in response to favourable temperature and moisture conditions

[4, 46]

. The importance value indices for species with autochorous seed dispersal differed from those with anemochorous dispersal, reflecting variation in seed dispersal. This is probably because self-dispersed seeds are often dispersed over short distances, which can restrict colonisation potential

[53, 59]

. Our findings that seed mass significantly influences plant survival of AGV are not isolated, as seed mass not only affects germination success but also shapes broader ecological strategies for plant growth and reproduction

[7]

. While seed mass is a relevant trait for understanding SSBs, they are unreliable when predicting AGV dominance. Additionally, functional traits such as plant height, deciduousness, growth form, life cycle, fruit type, and dispersal syndrome were not associated AGV importance value indices and survival because they reflect competitive strategies in AGV that are less relevant to the SSB

[8, 14, 23, 39]

Canopy cover and leaf litter layers act as ecological filters that influence composition by interacting with functional traits such as seed size

[29]

. Our study showed lower survival rates for small-seeded species such as Senna didymobotrya and Piper capense, which is concurrent with areas of higher canopy cover and litter accumulation. This pattern is consistent with our finding of a negative relationship between canopy cover and invasive species cover, as well as between invasive cover and SSB diversity. Our results suggest that invasive species management gradually contributes to ecological restoration, but invasive removal alone is insufficient for long-term recovery. While initial removal of invasive species reduces their dominance, they regenerate from the SSB if not actively managed

[13, 16, 20, 61, 66]

. The little overlap in AGV across removal treatments suggests that active measures such as repeated clearing, planting, and reseeding are necessary for restoration in the long-term.

Our results reveal within-community dissimilarity between the SSB and the AGV in the restored forest and highlight differences in species richness across sampling sites (Figure 5). In the present study, as well as in other disturbed sites, such as those affected by overgrazing, a weak correlation between the SSB and AGV has been observed

[1, 4]

. Bekele et al

[4]

demonstrated that different land-use types in Ethiopia’s Buska Mountains resulted in variable SSB compositions and little overlap with AGV. Conversely, a study conducted in a cool-temperate old-growth forest highlighted that the SSB contributed to the forest regeneration, with its composition closely matching the AGV, thereby supporting restoration efforts

[54]

. Many of these contrasting findings highlight regional variability but also diversity in restoration sites and land use history. For instance, ceasing utilisation of ecosystems such as wetlands, where favourable conditions enhance seed preservation and natural regeneration, is likely to yield disparate restoration outcomes

[22]

. As a result, context-specific research is required to understand the role of AGV and SSB in shaping plant communities in order to avoid restoration failures

[42, 65]

Finally, the design of this study is observational rather than experimental; plots were selected based on past invasive species removal, which limits causal inference. Pre-existing differences among plots such as soil conditions, proximity to seed sources, land-use history, or management intensity may have influenced the observed patterns. The AGV was surveyed once at baseline, restricting our ability to detect community-level compositional changes, or shifts in dominance over time. The sample sizes were small, limiting statistical power, and; while regenerants were repeatedly monitored to estimate survival rates, individual-level data may not fully capture broader community dynamics. Finally, while functional traits and soil properties were analyzed in relation to vegetation and regeneration patterns, these analyses are correlative and do not establish causation. Therefore, caution should be exercised when interpreting the results and we recommend further studies with larger, randomized, and repeated surveys to validate these results.

5. Conclusions

Our findings show that native plant recovery can be accelerated by removal of invasive species; however, diversity differences exist between AGV and SSB, and these differences were not necessarily modulated by plant functional traits and soil characteristics. This variation in composition of species indicates a limited potential for natural regeneration from seed banks, despite removal of invasive species. Effective restoration in the East Africa forests is less likely to be successful if these ecosystems are poorly understood and if the opportunities and challenges for natural regeneration from AGV and SSB are not factored into restoration trajectories. In order to achieve the desired outcomes, regeneration can be complemented by targeted seeding, planting of seedlings and improving soil health to promote germination and propagule survival.

Abbreviations

AGV	Above-Ground Vegetation
AIC	Akaike Information Criterion
BBGF	Brackenhurst Botanical Garden and Forest
CCA	Canonical Correspondence Analysis
DBH	Diameter at Breast Height
GIFT	Global Inventory of Floras and Traits
GLM	Generalised Linear Model
ISTA	International Seed Testing Association
IVI	Importance Value Index
KALRO	Kenya Agricultural & Livestock Research Organization
LRT	Likelihood Ratio Test
RCD	Root Collar Diameter
RD	Relative Density
RDO	Relative Dominance
RF	Relative Frequency
SE	Standard Error
SER	Society for Ecological Restoration
SSB	Soil Seed Bank

Acknowledgments

We thank Prof. Stewart Thompson for his suggestions that greatly improved the quality of the original manuscript. We also appreciate Justin Oganga, Mercy Sigei and Shadrack Oduor for their assistance in the field. Special thanks to the many volunteers who, over the years, have helped with the removal of invasive species in the research sites.

Author Contributions

Anthony Karani: Data curation, Formal Analysis, Investigation, Methodology, Project administration, Visualization, Writing – original draft, Writing – review & editing

Andrew Gichira: Conceptualization, Methodology, Supervision, Writing – original draft, Writing – review & editing

Tobin Musembi: Conceptualization, Data curation, Investigation, Methodology, Project administration, Validation, Writing – original draft, Writing – review & editing

Lucy Adhiambo: Investigation, Methodology, Validation, Writing – original draft, Writing – review & editing

Victor Otieno: Conceptualization, Methodology, Resources, Supervision, Validation, Writing – review & editing

Jonathan Jenkins: Funding acquisition, Resources, Validation, Writing – review & editing

Data Availability Statement

The data collected and analysed in this study has been deposited in Zonedo (doi: 10.5281/zenodo.15753417).

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Al-Huqail, A. A., Al-Harbi, H. F., Alowaifeer, A. M., El-Sheikh, M. A., Assaeed, A. M., Alsaleem, T. S., Kassem, H. S., Azab, O. M., Dar, B. A., Malik, J. A., & Abd-ElGawad, A. M. (2025). Correlation between aboveground vegetation composition and soil seed bank of Raudhat desert habitat: A case study of Raudhat Alkhafs, Saudi Arabia. BMC Plant Biology, 25(1), 136. https://doi.org/10.1186/s12870-025-06162-0
[2]	Anju, V. M., Warrier, R. R., & Kunhikannan, C. (2022). Significance of soil seed bank in forest vegetation—A review. Seeds, 1(3), 181–197. https://doi.org/10.3390/seeds1030016
[3]	Ashiono, F., Kamiri, H., & Kinyanjui, M. (n.d.). Evaluation of mineral nutrition and growth of Eucalyptus saligna seedlings raised on organic-enriched nursery potting media. Journal of Research in Forestry, Wildlife & Environment, 11, 39–50.
[4]	Bekele, M., Demissew, S., Bekele, T., & Woldeyes, F. (2022). Soil seed bank distribution and restoration potential in the vegetation of Buska Mountain range, Hamar district, southwestern Ethiopia. Heliyon, 8(11), e11244. https://doi.org/10.1016/j.heliyon.2022.e11244
[5]	Birhanu, L., Bekele, T., Tesfaw, B., & Demissew, S. (2022). Soil seed bank composition and aboveground vegetation in dry Afromontane forest patches of Northwestern Ethiopia. Trees, Forests and People, 9, 100292. https://doi.org/10.1016/j.tfp.2022.100292
[6]	Brandt, A. J., Png, G. K., Jo, I., McGrannachan, C., Allen, K., Peltzer, D. A., D’Antonio, C., Dickie, I. A., French, K., Leishman, M. R., Ostertag, R., Parker, I. M., Stanley, M. C., Suding, K. N., & Bellingham, P. J. (2023). Managing multi-species plant invasions when interactions influence their impact. Frontiers in Ecology and the Environment, 21(8), 370–379. https://doi.org/10.1002/fee.2658
[7]	Buisson, E., Fidelis, A., Overbeck, G. E., Schmidt, I. B., Durigan, G., Young, T. P., Alvarado, S. T., Arruda, A. J., Boisson, S., Bond, W., Coutinho, A., Kirkman, K., Oliveira, R. S., Schmitt, M. H., Siebert, F., Siebert, S. J., Thompson, D. I., & Silveira, F. A. O. (2021). A research agenda for the restoration of tropical and subtropical grasslands and savannas. Restoration Ecology, 29(S1), e13292. https://doi.org/10.1111/rec.13292
[8]	Chapman, C. A., Kitajima, K., Zanne, A. E., Kaufman, L. S., & Lawes, M. J. (2008). A 10-year evaluation of the functional basis for regeneration habitat preference of trees in an African evergreen forest. Forest Ecology and Management, 255(11), 3790–3796. https://doi.org/10.1016/j.foreco.2008.03.016
[9]	Chen, S., Hu, X., Baskin, C. C., & Baskin, J. M. (2024). A long-term experiment reveals no trade-off between seed persistence and seedling emergence. New Phytologist, 241(2), 623–631. https://doi.org/10.1111/nph.19270
[10]	Dann, L. E., Guja, L., Kark, S., & Dwyer, J. (2024). Comparative study reveals management of a dominant invasive plant facilitates subtropical forest regeneration. Biological Invasions, 26(1), 299–313. https://doi.org/10.1007/s10530-023-03174-5
[11]	Denelle, P., Weigelt, P., & Kreft, H. (2023). gift—An r package to access the global inventory of floras and traits. Methods in Ecology and Evolution, 14(11), 2738–2748. https://doi.org/10.1111/2041-210X.14213
[12]	Dhakal, B., Pinard, M. A., Gunatilleke, I. A. U. N., Gunatilleke, C. V. S., & Burslem, D. F. R. P. (2015). Strategies for restoring tree seedling recruitment in high conservation value tropical montane forests underplanted with cardamom. Applied Vegetation Science, 18(1), 121–133. https://doi.org/10.1111/avsc.12129
[13]	Dyderski, M. K., & Jagodziński, A. M. (2020). Impact of invasive tree species on natural regeneration species composition, diversity, and density. Forests, 11(4), 456. https://doi.org/10.3390/f11040456
[14]	Egeta, D., Yadesa, G., Eshete, A., Belay, H., Charu, U., & Teshome, T. (2024). Woody species composition, structure, and soil seed bank of the degraded parts of the gera moist afromontane forest, southwestern ethiopia. International Journal of Forestry Research, 2024(1), 9849957. https://doi.org/10.1155/2024/9849957
[15]	Fabšičová, M., Vymyslický, T., Frei, I., Zdražílková, M., Smetanová, S., Winkler, J., & Jiroušek, M. (2024). The importance of soil seed banks for biodiversity restoration in degraded grasslands. Folia Geobotanica, 59(1), 17–37. https://doi.org/10.1007/s12224-024-09452-x
[16]	Flory, S. L., & Clay, K. (2009). Invasive plant removal method determines native plant community responses. Journal of Applied Ecology, 46(2), 434–442. https://doi.org/10.1111/j.1365-2664.2009.01610.x
[17]	Gann, G. D., McDonald, T., Walder, B., Aronson, J., Nelson, C. R., Jonson, J., Hallett, J. G., Eisenberg, C., Guariguata, M. R., Liu, J., Hua, F., Echeverría, C., Gonzales, E., Shaw, N., Decleer, K., & Dixon, K. W. (2019). International principles and standards for the practice of ecological restoration. Second edition. Restoration Ecology, 27(S1). https://doi.org/10.1111/rec.13035
[18]	Gioria, M., Carta, A., Baskin, C. C., Dawson, W., Essl, F., Kreft, H., Pergl, J., Van Kleunen, M., Weigelt, P., Winter, M., & Pyšek, P. (2021). Persistent soil seed banks promote naturalisation and invasiveness in flowering plants. Ecology Letters, 24(8), 1655–1667. https://doi.org/10.1111/ele.13783
[19]	Guo, Y., Li, Y., Li, J., Li, J., Wen, S., Huang, F., He, W., Wang, B., Lu, S., Li, D., Xiang, W., & Li, X. (2022). Comparison of aboveground vegetation and soil seed bank composition among three typical vegetation types in the karst regions of southwest china. Agronomy, 12(8), 1871. https://doi.org/10.3390/agronomy12081871
[20]	Hinkson, K. M., NeSmith, J. E., Alba, C., Durham, M., Ferrell, J., & Flory, S. L. (2024). Selective method for invasive plant removal enhances restoration. Restoration Ecology, 32(4), e14112. https://doi.org/10.1111/rec.14112
[21]	ISTA. (2024). International Rules for Seed Testing: Sampling. International Rules for Seed Testing. International Rules for Seed Testing, 2024(1), 1–52. https://doi.org/10.15258/istarules.2023.02
[22]	Jakovac, C. C., Junqueira, A. B., Crouzeilles, R., Peña-Claros, M., Mesquita, R. C. G., & Bongers, F. (2021). The role of land-use history in driving successional pathways and its implications for the restoration of tropical forests. Biological Reviews, 96(4), 1114–1134. https://doi.org/10.1111/brv.12694
[23]	Jennifer, N. M., J, I. K., R, M. C., & W, M. (2011). Assessment of soil seed bank from six different vegetation types in Kakamega forest, Western Kenya. African Journal of Biotechnology, 10(65), 14384–14391. https://doi.org/10.5897/AJB11.1476
[24]	Kaigongi, M. M., Muturi, G. M., Kigomo, J. N., Gathara, M., & Otuoma, J. (2023). Mixed species natural forest regeneration trajectory in clear-felled monoculture plantation sites in Kenya: A step towards developing a natural forests restoration framework. African Journal of Ecology, 61(2), 513–518. https://doi.org/10.1111/aje.13102
[25]	Karani, A., & Njoroge, L. (2025). Southernmost record of the threatened platycypha amboniensis martin 1915 (Odonata: Chlorocyphidae), endemic to the highlands of central kenya. Entomological Communications, 7, ec07015. https://doi.org/10.37486/2675-1305.ec07015
[26]	Kikoti, I. A., Ndangalasi, H. J., Kayombo, C. J., & Musoma, R. M. (2025). Soil seed bank composition and diversity in areas invaded with invasive alien species in the lower montane forest of kilimanjaro national park, tanzania. East African Journal of Environment and Natural Resources, 8(1), 195–218. https://doi.org/10.37284/eajenr.8.1.2873
[27]	Kipkoech, S., Melly, D. K., Watuma Muema, B., Wei, N., Kamau, P., Kirika, P. M., Wang, Q., & Hu, G. (2020). An annotated checklist of the vascular plants of aberdare ranges forest, a part of eastern afromontane biodiversity hotspot. PhytoKeys, 149, 1–88. https://doi.org/10.3897/phytokeys.149.48042
[28]	Kovács-Hostyánszki, A., Szigeti, V., Miholcsa, Z., Sándor, D., Soltész, Z., Török, E., & Fenesi, A. (2022). Threats and benefits of invasive alien plant species on pollinators. Basic and Applied Ecology, 64, 89–102. https://doi.org/10.1016/j.baae.2022.07.003
[29]	Lenda, M., Steudel, B., Skórka, P., Zagrodzka, Z. B., Moroń, D., Bączek-Kwinta, R., Janowiak, F., Baran, A., Possingham, H. P., & Knops, J. M. H. (2023). Multiple invasive species affect germination, growth, and photosynthesis of native weeds and crops in experiments. Scientific Reports, 13(1), 22146. https://doi.org/10.1038/s41598-023-48421-w
[30]	Macera, L. G., Pereira, S. R., & Souza, A. L. T. D. (2017). Survival and growth of tree seedlings as a function of seed size in a gallery forest under restoration. Acta Botanica Brasilica, 31(4), 539–545. https://doi.org/10.1590/0102-33062017abb0075
[31]	Makokha, J. (2018). Invasion of < i> Cestrum aurantiacum</i> Lindl. In Kenya. Journal of Environmental Protection, 09(06), 671–690. https://doi.org/10.4236/jep.2018.96042
[32]	Metz, J., Liancourt, P., Kigel, J., Harel, D., Sternberg, M., & Tielbörger, K. (2010). Plant survival in relation to seed size along environmental gradients: A long-term study from semi-arid and Mediterranean annual plant communities. Journal of Ecology, 98(3), 697–704. https://doi.org/10.1111/j.1365-2745.2010.01652.x
[33]	Mganga, K. Z., Kaindi, E., Ndathi, A. J. N., Bosma, L., Kioko, T., Kadenyi, N., Wambua, S. M., Van Steenbergen, F., & Musimba, N. K. R. (2021). Morphoecological characteristics of grasses used to restore degraded semi-arid African rangelands. Ecological Solutions and Evidence, 2(2), e12078. https://doi.org/10.1002/2688-8319.12078
[34]	Miao, R., Song, Y., Sun, Z., Guo, M., Zhou, Z., & Liu, Y. (2016). Soil seed bank and plant community development in passive restoration of degraded sandy grasslands. Sustainability, 8(6), 581. https://doi.org/10.3390/su8060581
[35]	Mndela, M., Madakadze, C. I., Nherera-Chokuda, F., & Dube, S. (2020). Is the soil seed bank a reliable source for passive restoration of bush-cleared semi-arid rangelands of South Africa? Ecological Processes, 9(1), 1. https://doi.org/10.1186/s13717-019-0204-6
[36]	Mohammed, S. A., & Denboba, M. A. (2020). Study of soil seed banks in ex-closures for restoration of degraded lands in the central rift valley of ethiopia. Scientific Reports, 10(1), 956. https://doi.org/10.1038/s41598-020-57651-1
[37]	Mungi, N. A., Qureshi, Q., & Jhala, Y. V. (2023). Distribution, drivers and restoration priorities of plant invasions in India. Journal of Applied Ecology, 60(11), 2400–2412. https://doi.org/10.1111/1365-2664.14506
[38]	Nicholson, M. (2010). Brackenhurst Forest Botanic Garden, Kenya: Towards a self-sustaining botanic garden. Proceedings of the 4th Global Botanic Gardens Congress.
[39]	Ojija, F., Petruzzellis, F., & Bacaro, G. (2024). Review of invasive plant functional traits and management using remote sensing in sub-saharan africa. International Journal of Plant Biology, 15(2), 358–374. https://doi.org/10.3390/ijpb15020029
[40]	Oksanen, J., Blanchet, F. G., Kindt, R., Legendre, P., Minchin, P. R., O’Hara, R. B., Simpson, G. L., Solymos, P., Stevens, M. H. H., & Wagner, H. (2019). vegan: Community Ecology Package [R package version 2. 5-6. https://cran.r-project.org/web/packages/vegan/vegan.pdf
[41]	Pedrini, S., & Dixon, K. W. (2020). International principles and standards for native seeds in ecological restoration. Restoration Ecology, 28(S3). https://doi.org/10.1111/rec.13155
[42]	Perring, M. P., Standish, R. J., Price, J. N., Craig, M. D., Erickson, T. E., Ruthrof, K. X., Whiteley, A. S., Valentine, L. E., & Hobbs, R. J. (2015). Advances in restoration ecology: Rising to the challenges of the coming decades. Ecosphere, 6(8), 1–25. https://doi.org/10.1890/ES15-00121.1
[43]	Plohák, P., Švehláková, H., Stalmachová, B., Goňo, M., & Dvorský, T. (2025). Combining extraction and cultivation methods for soil seed bank analysis increases number of captured species and their similarity to above-ground vegetation. Frontiers in Plant Science, 15, 1500941. https://doi.org/10.3389/fpls.2024.1500941
[44]	Pyšek, P., Jarošík, V., Hulme, P. E., Pergl, J., Hejda, M., Schaffner, U., & Vilà, M. (2012). A global assessment of invasive plant impacts on resident species, communities and ecosystems: The interaction of impact measures, invading species’ traits and environment. Global Change Biology, 18(5), 1725–1737. https://doi.org/10.1111/j.1365-2486.2011.02636.x
[45]	R Core Team. (2024). _R: A Language and Environment for Statistical Computing_ [Computer software]. R Foundation for Statistical Computing. https://www.R-project.org/
[46]	Rahayu, S., Pambudi, S., Permadi, D., Tata, H. L., Martini, E., Rasnovi, S., Nuroniah, H. S., Kindt, R., Nugraha, M., Dewi, S., & Van Noordwijk, M. (2022). Functional trait profiles and diversity of trees regenerating in disturbed tropical forests and agroforests in Indonesia. Forest Ecosystems, 9, 100030. https://doi.org/10.1016/j.fecs.2022.100030
[47]	Ricotta, C., & Szeidl, L. (2009). Diversity partitioning of Rao’s quadratic entropy. Theoretical Population Biology, 76(4), 299–302. https://doi.org/10.1016/j.tpb.2009.10.001
[48]	Rose, S., & Poorter, L. (2003). The importance of seed mass for early regeneration in tropical forest: A review. In Long-term changes in tropical tree diversity: Studies from the Guiana Shield, Africa, Borneo and Melanesia (pp. 19–35). Tropenbos International. https://edepot.wur.nl/39801
[49]	Ruwanza, S. (2021). Effects of solanum mauritianum scopoli (Bugweed) invasion on soil and vegetation in vhembe biosphere reserve, south africa. Austral Ecology, 46(3), 342–348. https://doi.org/10.1111/aec.12999
[50]	Sanou, L., Zida, D., Savadogo, P., & Thiombiano, A. (2018). Comparison of aboveground vegetation and soil seed bank composition at sites of different grazing intensity around a savanna-woodland watering point in West Africa. Journal of Plant Research, 131(5), 773–788. https://doi.org/10.1007/s10265-018-1048-3
[51]	Shaw, K., Nicholson, M., & Hardwick, K. (2015). Encouraging and Enabling a Science-Based Approach to Ecological Restoration: An Introduction to the Work of the Ecological Restoration Alliance of Botanic Gardens (ERA). Sibbaldia: The International Journal of Botanic Garden Horticulture, 13, 145–152.
[52]	Shaw, K., Ruyonga, G., & Nicholson, M. (2016). Enhancing Tree Conservation and Forest Restoration in East Africa. BGjournal, 13, 28–31.
[53]	Spînu, A. P., Mysiak, W., Bauhus, J., Bielak, K., & Niklasson, M. (2023). Pioneer tree species accelerate restoration of tree-related microhabitats in 50-year-old reserves of Białowieża Forest, Poland. Ecology and Evolution, 13(7), e10238. https://doi.org/10.1002/ece3.10238
[54]	Tamura, A. (2016). Potential of soil seed banks in the ecological restoration of overgrazed floor vegetation in a cool-temperate old-growth damp forest in eastern Japan. Journal of Forest Research, 21(1), 43–56. https://doi.org/10.1007/s10310-015-0509-y
[55]	Tessema, Z. K., Ejigu, B., & Nigatu, L. (2017). Tree species determine soil seed bank composition and its similarity with understory vegetation in a semi-arid African savanna. Ecological Processes, 6(1), 9. https://doi.org/10.1186/s13717-017-0075-7
[56]	Toma, T. S. P., Overbeck, G. E., Mendonça, M. D. S., & Fernandes, G. W. (2023). Optimal references for ecological restoration: The need to protect references in the tropics. Perspectives in Ecology and Conservation, 21(1), 25–32. https://doi.org/10.1016/j.pecon.2023.01.003
[57]	Tóth, Á., Deák, B., Kelemen, A., Kiss, R., Lukács, K., Bátori, Z., & Valkó, O. (2025). Vertical stratification of the soil seed bank in wet grasslands and its implications for restoration. Community Ecology, 26(1), 131–142. https://doi.org/10.1007/s42974-024-00226-1
[58]	Ulyshen, M. D., Horn, S., & Hanula, J. L. (2022). Decadal patterns of forest and pollinator recovery following the eradication of an invasive shrub. Frontiers in Ecology and Evolution, 10, 832268. https://doi.org/10.3389/fevo.2022.832268
[59]	Viani, R. A. G., Vidas, N. B., Pardi, M. M., Castro, D. C. V., Gusson, E., & Brancalion, P. H. S. (2015). Animal-dispersed pioneer trees enhance the early regeneration in Atlantic Forest restoration plantations. Natureza & Conservação, 13(1), 41–46. https://doi.org/10.1016/j.ncon.2015.03.005
[60]	Vujanović, D., Losapio, G., Milić, S., & Milić, D. (2022). The impact of multiple species invasion on soil and plant communities’ increases with invasive species co-occurrence. Frontiers in Plant Science, 13, 875824. https://doi.org/10.3389/fpls.2022.875824
[61]	Walentowitz, A., Manthey, M., Bentet Preciado, M. B., Chango, R., Sevilla, C., & Jäger, H. (2021). Limited natural regeneration of unique Scalesia forest following invasive plant removal in Galapagos. PLOS ONE, 16(10), e0258467. https://doi.org/10.1371/journal.pone.0258467
[62]	Weidlich, E. W. A., Flórido, F. G., Sorrini, T. B., & Brancalion, P. H. S. (2020). Controlling invasive plant species in ecological restoration: A global review. Journal of Applied Ecology, 57(9), 1806–1817. https://doi.org/10.1111/1365-2664.13656
[63]	Weigelt, P., König, C., & Kreft, H. (2020). Gift – a global inventory of floras and traits for macroecology and biogeography. Journal of Biogeography, 47(1), 16–43. https://doi.org/10.1111/jbi.13623
[64]	Witt, A., Beale, T., & Van Wilgen, B. W. (2018). An assessment of the distribution and potential ecological impacts of invasive alien plant species in eastern Africa. Transactions of the Royal Society of South Africa, 73(3), 217–236. https://doi.org/10.1080/0035919X.2018.1529003
[65]	Wortley, L., Hero, J., & Howes, M. (2013). Evaluating ecological restoration success: A review of the literature. Restoration Ecology, 21(5), 537–543. https://doi.org/10.1111/rec.12028
[66]	Zenni, R. D., Da Cunha, W. L., Musso, C., De Souza, J. V., Nardoto, G. B., & Miranda, H. S. (2020). Synergistic impacts of co-occurring invasive grasses cause persistent effects in the soil-plant system after selective removal. Functional Ecology, 34(5), 1102–1112. https://doi.org/10.1111/1365-2435.13524
[67]	Zhou, Y., Liu, B., Mbuni, Y., Yan, X., Mwachala, G., Hu, G., & Wang, Q. (2017). Vascular flora of kenya, based on the flora of tropical east africa. PhytoKeys, 90, 113–126. https://doi.org/10.3897/phytokeys.90.20531

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Karani, A., Gichira, A., Musembi, T., Adhiambo, L., Otieno, V., et al. (2026). Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank. Journal of Plant Sciences, 14(2), 79-92. https://doi.org/10.11648/j.jps.20261402.12

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Karani, A.; Gichira, A.; Musembi, T.; Adhiambo, L.; Otieno, V., et al. Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank. J. Plant Sci. 2026, 14(2), 79-92. doi: 10.11648/j.jps.20261402.12

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AMA Style

Karani A, Gichira A, Musembi T, Adhiambo L, Otieno V, et al. Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank. J Plant Sci. 2026;14(2):79-92. doi: 10.11648/j.jps.20261402.12

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@article{10.11648/j.jps.20261402.12,
  author = {Anthony Karani and Andrew Gichira and Tobin Musembi and Lucy Adhiambo and Victor Otieno and Jonathan Jenkins},
  title = {Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank},
  journal = {Journal of Plant Sciences},
  volume = {14},
  number = {2},
  pages = {79-92},
  doi = {10.11648/j.jps.20261402.12},
  url = {https://doi.org/10.11648/j.jps.20261402.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.jps.20261402.12},
  abstract = {Ecological restoration partially relies on plant regeneration from the above-ground vegetation (AGV) and soil seed banks (SSB); however, the co-occurrence of species in these sources vary across ecosystems. In this study, we measured soil properties and surveyed SSB and AGV, monitored regenerants for two years to estimate survival rates. We assessed the variation of species abundance in AGV, SSB and natural regenerants using a log-linear model and tested for correlation between soil properties using Pearson’s correlation coefficient and the association between the importance value index and survival rate of regenerants using generalised linear models. We found within-community dissimilarity between AGV and SSB, and the co-occurrence of species was predicted by periods of invasive species removal. There were five (4.46%) common species and five (4.46%), 34 (30.36%) and 42 (37.5%) exclusive species in natural regenerants, SSB and AGV, respectively. The common species among all periods of invasive species removal were 12.5%, 20%, and 41.7% in AGV, natural regenerants, and SSB, respectively. The diversity of SSB was positively associated with the survival rate of regenerants, but not AGV diversity. Survival rates of regenerants were associated with seed mass but not plant height, while plant functional traits were not associated with importance value indices of AGV. These findings show that native plant recovery can be accelerated by removal of invasive species; however, diversity differences exist between AGV and SSB, which were not necessarily modulated by plant functional traits and soil characteristics.},
 year = {2026}
}

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TY  - JOUR
T1  - Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank
AU  - Anthony Karani
AU  - Andrew Gichira
AU  - Tobin Musembi
AU  - Lucy Adhiambo
AU  - Victor Otieno
AU  - Jonathan Jenkins
Y1  - 2026/03/26
PY  - 2026
N1  - https://doi.org/10.11648/j.jps.20261402.12
DO  - 10.11648/j.jps.20261402.12
T2  - Journal of Plant Sciences
JF  - Journal of Plant Sciences
JO  - Journal of Plant Sciences
SP  - 79
EP  - 92
PB  - Science Publishing Group
SN  - 2331-0731
UR  - https://doi.org/10.11648/j.jps.20261402.12
AB  - Ecological restoration partially relies on plant regeneration from the above-ground vegetation (AGV) and soil seed banks (SSB); however, the co-occurrence of species in these sources vary across ecosystems. In this study, we measured soil properties and surveyed SSB and AGV, monitored regenerants for two years to estimate survival rates. We assessed the variation of species abundance in AGV, SSB and natural regenerants using a log-linear model and tested for correlation between soil properties using Pearson’s correlation coefficient and the association between the importance value index and survival rate of regenerants using generalised linear models. We found within-community dissimilarity between AGV and SSB, and the co-occurrence of species was predicted by periods of invasive species removal. There were five (4.46%) common species and five (4.46%), 34 (30.36%) and 42 (37.5%) exclusive species in natural regenerants, SSB and AGV, respectively. The common species among all periods of invasive species removal were 12.5%, 20%, and 41.7% in AGV, natural regenerants, and SSB, respectively. The diversity of SSB was positively associated with the survival rate of regenerants, but not AGV diversity. Survival rates of regenerants were associated with seed mass but not plant height, while plant functional traits were not associated with importance value indices of AGV. These findings show that native plant recovery can be accelerated by removal of invasive species; however, diversity differences exist between AGV and SSB, which were not necessarily modulated by plant functional traits and soil characteristics.
VL  - 14
IS  - 2
ER  -

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Author Information

Anthony Karani

Centre for Ecosystem Restoration, Limuru, Kenya;Department of Biological Sciences, University of Embu, Embu, Kenya

Contact Email

http://orcid.org/0000-0001-8547-9847
Andrew Gichira

Centre for Ecosystem Restoration, Limuru, Kenya

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http://orcid.org/0000-0002-0530-7605
Tobin Musembi

Centre for Ecosystem Restoration, Limuru, Kenya

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http://orcid.org/0009-0001-1749-8162
Lucy Adhiambo

Centre for Ecosystem Restoration, Limuru, Kenya

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http://orcid.org/0000-0001-9706-4753
Victor Otieno

Centre for Ecosystem Restoration, Limuru, Kenya

Contact Email

http://orcid.org/0000-0002-7342-5312
Jonathan Jenkins

Centre for Ecosystem Restoration, Limuru, Kenya

Contact Email

http://orcid.org/0009-0006-6830-8775

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Table 1

Table 1. Generalised linear model (GLM) results showing the effects of plant height and seed mass on plant survival rate and importance value indices of above-ground vegetation. The table shows estimates, standard errors (SE), p-values, and Akaike’s Information Criteria (AIC). Significant predictors (p < 0.05) are indicated with an asterisk (*).

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APA Style

Karani, A., Gichira, A., Musembi, T., Adhiambo, L., Otieno, V., et al. (2026). Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank. Journal of Plant Sciences, 14(2), 79-92. https://doi.org/10.11648/j.jps.20261402.12

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ACS Style

Karani, A.; Gichira, A.; Musembi, T.; Adhiambo, L.; Otieno, V., et al. Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank. J. Plant Sci. 2026, 14(2), 79-92. doi: 10.11648/j.jps.20261402.12

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AMA Style

Karani A, Gichira A, Musembi T, Adhiambo L, Otieno V, et al. Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank. J Plant Sci. 2026;14(2):79-92. doi: 10.11648/j.jps.20261402.12

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@article{10.11648/j.jps.20261402.12,
  author = {Anthony Karani and Andrew Gichira and Tobin Musembi and Lucy Adhiambo and Victor Otieno and Jonathan Jenkins},
  title = {Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank},
  journal = {Journal of Plant Sciences},
  volume = {14},
  number = {2},
  pages = {79-92},
  doi = {10.11648/j.jps.20261402.12},
  url = {https://doi.org/10.11648/j.jps.20261402.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.jps.20261402.12},
  abstract = {Ecological restoration partially relies on plant regeneration from the above-ground vegetation (AGV) and soil seed banks (SSB); however, the co-occurrence of species in these sources vary across ecosystems. In this study, we measured soil properties and surveyed SSB and AGV, monitored regenerants for two years to estimate survival rates. We assessed the variation of species abundance in AGV, SSB and natural regenerants using a log-linear model and tested for correlation between soil properties using Pearson’s correlation coefficient and the association between the importance value index and survival rate of regenerants using generalised linear models. We found within-community dissimilarity between AGV and SSB, and the co-occurrence of species was predicted by periods of invasive species removal. There were five (4.46%) common species and five (4.46%), 34 (30.36%) and 42 (37.5%) exclusive species in natural regenerants, SSB and AGV, respectively. The common species among all periods of invasive species removal were 12.5%, 20%, and 41.7% in AGV, natural regenerants, and SSB, respectively. The diversity of SSB was positively associated with the survival rate of regenerants, but not AGV diversity. Survival rates of regenerants were associated with seed mass but not plant height, while plant functional traits were not associated with importance value indices of AGV. These findings show that native plant recovery can be accelerated by removal of invasive species; however, diversity differences exist between AGV and SSB, which were not necessarily modulated by plant functional traits and soil characteristics.},
 year = {2026}
}

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TY  - JOUR
T1  - Implications of Invasive Species Removal, Soil Properties and Plant Functional Traits on Survival and Co-occurrence of Above-ground Vegetation with Soil Seed Bank
AU  - Anthony Karani
AU  - Andrew Gichira
AU  - Tobin Musembi
AU  - Lucy Adhiambo
AU  - Victor Otieno
AU  - Jonathan Jenkins
Y1  - 2026/03/26
PY  - 2026
N1  - https://doi.org/10.11648/j.jps.20261402.12
DO  - 10.11648/j.jps.20261402.12
T2  - Journal of Plant Sciences
JF  - Journal of Plant Sciences
JO  - Journal of Plant Sciences
SP  - 79
EP  - 92
PB  - Science Publishing Group
SN  - 2331-0731
UR  - https://doi.org/10.11648/j.jps.20261402.12
AB  - Ecological restoration partially relies on plant regeneration from the above-ground vegetation (AGV) and soil seed banks (SSB); however, the co-occurrence of species in these sources vary across ecosystems. In this study, we measured soil properties and surveyed SSB and AGV, monitored regenerants for two years to estimate survival rates. We assessed the variation of species abundance in AGV, SSB and natural regenerants using a log-linear model and tested for correlation between soil properties using Pearson’s correlation coefficient and the association between the importance value index and survival rate of regenerants using generalised linear models. We found within-community dissimilarity between AGV and SSB, and the co-occurrence of species was predicted by periods of invasive species removal. There were five (4.46%) common species and five (4.46%), 34 (30.36%) and 42 (37.5%) exclusive species in natural regenerants, SSB and AGV, respectively. The common species among all periods of invasive species removal were 12.5%, 20%, and 41.7% in AGV, natural regenerants, and SSB, respectively. The diversity of SSB was positively associated with the survival rate of regenerants, but not AGV diversity. Survival rates of regenerants were associated with seed mass but not plant height, while plant functional traits were not associated with importance value indices of AGV. These findings show that native plant recovery can be accelerated by removal of invasive species; however, diversity differences exist between AGV and SSB, which were not necessarily modulated by plant functional traits and soil characteristics.
VL  - 14
IS  - 2
ER  -

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