Shifting Sands: A Meta-Analysis of Climate Change Impacts on the Distribution and Phenology of Key Woody Plant Species in the Kalahari Ecosystem, Botswana (2020-2024)

© The Author(s) 2025. Published by AMO Publisher. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https:// creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. Shifting Sands: A Meta-Analysis of Climate Change Impacts on the Distribution and Phenology of Key Woody Plant Species in the Kalahari Ecosystem, Botswana (2020-2024) Tachenama Modo  College of Environmental Science and Engineering, Institute of Environment and Sustainable Development (IESD), Tongji University, 1234 Siping Road, Shanghai 200092, China Article History: Received: 22.09.2025 Revised: 13.10.2025 Accepted: 14.10.2025 Published: 15.10.2025 Abstract This study encompasses a meta-analysis of surveys conducted from January 2020 to December 2024 focused on the effects of climate change on the distribution and phenology of the most dominant woody species in the Kalahari ecosystem of Botswana. The anticipation of these challenges is the basis of the conservation and adaptive management. The meta-analysis to the 35 studies included in the research confirms the presence of a significant trend in range shifts toward the poles and uplands for some dominant woody species (weighted average effect size d = 0.42, p < 0.001), indicating a reduced extent of favorable habitat at lower latitudes and elevations. The most pronounced changes in flowering and leafing phenology were more than two standard deviations and were accelerating at a rate above the longterm trend (weighted average effect size: d =-0.31, p<0.001). This indicates shifts in the functioning of ecosystems and plant-pollinator dynamics. In particular, meta-regression analysis revealed range shifts were predicted by the degree of seasonality in rainfall, where species in regions with more pronounced dry season pairs showed greater shifts (dry β =-0.15; p<0.01). Does the same hold for the species that perform poorer during dry spells and are known to develop shallower roots? These are the species that showed a greater rate of advance in leafing phenology (β=-0.12; p<0.01), and that is perhaps because of their greater sensitivity to soil moisture changes. Keywords: Climate change, Adverse impacts, Meta analysis, Kalahari Ecosystem, Phenology, Woody plants. Suggested citation: Modo, T. (2025). Shifting Sands: A Meta-Analysis of Climate Change Impacts on the Distribution and Phenology of Key Woody Plant Species in the Kalahari Ecosystem, Botswana (2020-2024). European Journal of Theoretical and Applied Sciences, 3(6), 15-35. https://doi.org/10.59324/ejtas.2025.3(6).02 Introduction The Kalahari ecosystem, which stretches across Botswana, Namibia, and South Africa, is the world’s largest unbroken sandy area (Thomas & Shaw, 2021). The Kalahari covers an area featuring a dry and patchy savanna, shrubland, and grasslands which provide homes to a wide diversity of plant species that are fundamental to the economy, social life, and many other ecosystem services Shackleton & Shackleton (2018). The ecosystem relies heavily on these species for soil and sand fixation, carbon sink, and nutrients cycling (Smith et al, 2015). To maintain the Kalahari and its ecosystem, it is vital to appreciate the dynamics that informal economies have in the developing world, particularly woody plants. www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 16 The Kalahari region is no different than other parts of the world regarding the ever-growing concern of climate change. Since the IPCC of 2021, there has been a shift of concern regarding the soared temperature averages as well as the erratic change of rainfall, and the unpredictable drought cycles. These changes have an impact on the Kalahari’s woody plants and other similar species. There could possibly be a loss and a shift of changes of the overall species in the ecosystem. The climate change is causing the Kalahari to lose species at a dramatic rate. The people who reside there also have to deal and find a way to restock these dwindling resources, and they seem to be losing hope, especially after Abiodun 2024.Research has started documenting the ways that different woody plant species are responding to climate change in the Kalahari. Some studies reported the range shifts of key species, with some species in the area moving to cooler and wetter regions (Maimbolwa et al. 2024). Other studies noticed the change in the timing of some phenological events, such as earlier flowering or leafing, that might change the plant–pollinator relations, reduce seed production, or be disrupted by the lack of pollinators (Musonda et al. 2023). Each of these studies contributes to a better understanding of the issue, but a comprehensive quantitative synthesis is required to examine the consequences of climate change on the Kalahari woody plant communities. Moreover, a number of recent studies emphasize the need to incorporate species-specific traits in predicting responses to climate change, and the how complex climate and biotic interactions act on an organism (Chidumayo & Gumbo, 2023; Setshogo, 2022). More than simply looking at individual case studies, there should have a broader perspective on factors that determine how a species respond to climate change, including individual level factors (drought resistance and mechanisms of seed dispersal), habitat factors (soil and hydrological regimes), and the interplay of various climate elements (temperature, precipitation, and CO2) (Thuiller et al, 2023). It is these interacting factors that will assist in formulating the best possible conservation and adaptive management frameworks to reduce the impacts of climate change on the Kalahari ecosystem. Niche theory says that with climate change, there are new sets of factors that are redefining the environments that make up a species’ niche, resulting in shifts in distribution and changes in the timing of recurring biological events (Pulliam, 2000). Moreover, and in the context of climate change, metacommunity theory says that the ability of a species to track changing climate in new areas is greatly determined by the level of dispersal and the degree of connectivity of the new regions (Leibold et al, 2004). Additionally, it is important to understand the boundaries of the current research and to point out the biases that exist in the literature today. For instance, the prevailing literature on the impacts of climate change may suffer from the publication bias, attributing to the overall effect of climate change, unproportionately, compared to literature that reports the contrary. Meta analysis, especially in its modern developments, fulfills this purpose of unrefined bias and evidence synthesis. Such recent developments in meta-analysis as explored by Viechtbauer (2010), provide precise methods to parse research heterogeneity and determine the roles of moderators on estimates of effect size. Rationale for this Meta-Analysis: This metaanalysis attempts to fill this critical gap in literature by quantitatively synthesizing recent research on the effects of climate change on the distribution and blooming times of major woody plants within the Kalahari ecosystem. This research aims to address the complexities of climate change resilience within this fragile region. This study aims to address the concerns raised in literature regarding the impact of climate change and the biodiversity crisis, with an emphasis on dryland ecosystems and key vegetation dynamics (Hannah et al., 2020; Scheffers et al., 2016). This study will describe the net impact of climate change on the distribution and blooming times of species, determine the primary drivers of species response, and evaluate the scope of publication bias in the literature. Furthermore, this metaanalysis seeks to further characterize the climate change resulting threats to the Kalahari and outline impact mitigation measures. www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 17 The purpose of this meta-analysis is to systematically and thoroughly bring together the pivotal themes and issues, and the responses of the woody plant communities of the Kalahari Desert to climate change. This research attempts to improve the existing literature, inform the climate and conservation policy discussion, and develop practices that ensure more efficient and sustainable climate change adaptation. This meta-analysis is expected to result in better and more precise approaches to mitigating and adapting to climate change in the Kalahari ecosystem. Objectives This meta-analysis has two central objectives: 1. Assess the impact of climate change on the distribution (range shifts) and phenology (timing of life cycle events) of selected key woody plant species in the Kalahari ecosystem, Botswana. 2. Examine and characterize factors that explain the variability of species responses to climate change, particularly species and habitat, and climate change. Literature Review The entire world is undergoing climate change, its impacts are being felt on ecosystems the world over, especially on semi-arid ecosystems like the Kalahari. Climate change scenarios predict increased temperature and changes in rainfall in ways that will drastically alter the distribution and timing of plant flowering and fruiting, having a domino effect on the structure and function of the entire ecosystem. In this literature review, the impacts of climate change on plant distribution and phenology are examined, with particular emphasis on the Kalahari ecosystem. Climate Change Impacts on Plant Distribution and Phenology Globally Studies encompassing various biomes have examined climate change impacts on plant distribution and phenology. Parmesan and Yohe (2003) conducted a meta-analysis and documented changing distribution patterns of a multitude of plant and animal species, confirming shifts in their ranges poleward and upslope. This indicates that species interact on a global level in response to warming temperatures. Advances in phenology and earlier flowering and leafing dates have also been documented in various regions by Menzel et al (2006). These shifts and modifications in plant distribution and phenology can disrupt the ecosystem processes that depend on plantpollinator relationships, the dynamics of carbon cycling, and the susceptibility to biotic invasions in a range of ecosystems (Cleland et al., 2007). More recent criticisms of climatic response models highlight the importance of ecological traits and context (Crimmins et al., 2011; Wolkovich et al., 2012). Recent research (2020-2024) continues to add information on the impact of climate change on plant communities. For instance, in research by Piao et al. (2019), the authors show that the intensity and the nature of plant phenological changes differ due to the interplay of temperature and moisture. In another study, Batllori et al. (2020) argues that climate change is likely to restrict the range and increase the extinction risk of species that are poorly dispersed, as they are less able to follow shifting suitable environments. Such research demonstrates that the plant responses to climate change are poorly understood and need further investigation. Kalahari Region Speculation on Climate Change According to applicable models, there will be relatively large changes to general temperature and precipitation patterns for the Kalahari region (IPCC, 2021) in the future. In Kalahari, levels of temperature are observed to increase by 2-4 degrees Celsius by the end of the 21st century. More specifically, by the end of the 21st century, the Kalahari region will experience an increase in surface temperature by 2 degrees Celsius and the central parts of the continent will warm by close to 4 degrees. Changes also include an increase in the variability of rainfall which is expected to be much greater than the rainfall itself, the average frequency, and the intensity of droughts and floods. The impact of climate change in the Kalahari Region will have lasting and positive changes on the region's plant communities and species composition change, www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 18 and will also improve the functionality and resilience of the _ecosystem_ to future climate changes (Davis et al., 2022; New, 2002). Engelbrecht et al. (2015) also stated that the region's aridity, coupled with the worryingly low levels of rainfall and the lack of _agricultural_ development_ accounts for the region's extreme vulnerability to the adverse effects of climate change. There have been some studies between 2020 and 2024 which attempt to improve understanding of climate change forecasting related to the Kalahari region. For example, Groves et al. (2008) added detail to the adaptation planning portion of their work by setting of local projections of temperature and precipitation changes using high resolution climate models. Kgathi et al. (2020) studied the consequences of climate change in the Kalahari region in terms of the availability of water and chronicled dwindling water supplies and increased competition as potential troubling outcomes. As these accounts suggest, the need to develop adaptive management strategies to deal with climate change impacts in the Kalahari ecosystem is growing. Particular Research on the Location and Phenology of Important Woody Plant Species in the Kalahari There are a number of works on the distribution and phenology of key woody plants species in the Kalahari that have contributed to knowledge on their responses to climate change. Moleele et al. (2023), for instance, documented the distribution of a number of woody plants and their responses to changing rainfall distributions. In another study, Musonda et al. (2023) reported on the phenology of flowering of several species that has shifted in the last few decades, and that has the potential of unbalancing plant-pollinator relationships. These studies offer insights into the climate change impacts, and its specifically on the Kalahari woody plant communities. Aimed at addressing the dynamics of key species of woody plants to climate change, the study by Maimbolwa et al, 2024, for instance, employs species distribution models to analyze the possible future range of Acacia erioloba and its projections under diverse climate change scenarios, showing at least its range will substantially contract in forthcoming decades. Krug (2017) examine the growth and the survivorship of Colophospermum mopane in the context of climate change and find the species to be relatively drought tolerant, although, somewhat prone to extreme heat. These studies underline the critical need for species and traitcentered approaches in understanding the impacts of climate change. The Role of Traits of Species and Characteristics of the Habitat in the Mediation of the Effects of Climate Change In plant communities the impacts of climate change are partially mediated by the traits of species and the characteristics of the habitat. For instance, the species that are more drought resistant are more likely to persist and reproduce in areas that are more arid, while the species that are more sedentary are less able to track climate change (Chesson, 2000; Tilman, 1994). Likewise, factors like soil type and the availability of water and nutrients in the habitat can reduce the impact of climate change on plant communities (Chapin et al., 1986; Grime, 1977). The impact of climate change on specific species and the attributes of the habitat needs to be understood so that effective conservation and adaptive management responses can be formulated. Recent studies have further reinforced the need to take into account species characteristics and habitats when assessing the likely impacts of climate change. For instance, Funk et al. (2017) noted that, in Mediterranean ecosystems, plant functional traits are among the strongest indicators of change in species due to climate change. Also, Ackerly et al. (2010) showed that plant community climate change impacts can be mitigated by habitat heterogeneity that provides different microclimates and resources. These studies illustrate the growing need to examine plant community impacts of climate change more comprehensively. Meta-Analytic Approaches in Ecology and Climate Change Research Meta-analysis serves as a crucial method for trying to combine the outcome of several studies in order to draw key conclusions that may exist www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 19 within the field of ecology and climate change (Gurevitch & Hedges, 1999). For instance, metaanalysis can evaluate the effects of climate change on the distribution and phenology of plants, determine factors that drive the species responses, and examine the extent of publication bias in the field (Koricheva et al., 2013). New developments in meta-analytic methods have made it easier to assess the issues of heterogeneity in studies, and to determine the role of moderators in effect sizes (Viechtbauer, 2010). There have been meta analyses of the impact climate change brings to plant communities. For one, Chen et al. (2011) described the shift of plant and animal species' geographic ranges to new regions, highlighting their movement in a poleward direction and to higher elevations. In another case, Wolkovich et al. (2012) found that in many places, plants are ‘getting smarter’— advancing their flowering time and leafing even further. These meta analyses are important in showing how climate change in a global sense. More such region-targeted meta-analyses are needed, even for the less-studied Kalahari, to provide better context for conservation and management. It is to the point, though, that the literature has been proved to contains a gap in relating regionecosystem such as the Kalahari with the concerning creased of shrub and tree distribution and the overall shift in blooming phenology that climate change invites. Speciation in a climactic change is a multifaceted issue and is likely better defined (if defined at all) through the consideration of traits of each species, habitat parameters, and even factors such as the under-review deforming bias in published literature. The Kalahari is still only a case example within the climate change discourse and so folds to accept further scrutiny and speculated parameters. Methodology This research has applied meta-analysis technique to synthesize empirical research regarding the impacts of climate change on keystone woody plant species in the Kalahari ecosystem along with their distribution and phenology. The use of meta-analysis in addressing a key research question spanning multiple independent studies and garnering different outcomes in different studies is indispensable in chronicling prominent trends and drawing conclusions regarding the congruence of different studies (Borenstein et al. 2009). This type of research is designed to focus on climate change and its variances on different geographical locations and studies. The impacts of climate change on different interactions and components of an ecosystem such as the Kalahari ecosystem pose great challenges to research (Gurevitch et al. 2018). The multifarious nature of ecological data and the broad variability in different methodologies designed for studying climate change impacts on Kalahari vegetation necessitates a meta-analysis for the development of a more comprehensive concept. Search Strategy Web of Science, Scopus, and Google Scholar were searched systematically to obtain relevant empirical studies. These were selected because of their extensive coverage of peer-reviewed scientific literature, including journals in ecology, climate change, and botany. The focus was on empirical studies published in the period January 2020 to December 2024 to extract the latest information available on the impacts of climate change on the Kalahari ecosystem. In addition, Google Scholar was employed to capture grey literature such as thesis, reports, and conference proceedings that may not be available in traditional databases. This is particularly relevant to the capture of research carried out by local Botswana and neighboring institutions which are often unpublished or absent in international journals (Haddaway et al., 2015). Myriad “climate change”, “Kalahari region”, “interested plant distribution”, and “interested plant phenology” keywords and phrases were strategically crafted and employed across databases. The phrases or keywords below were forged or selected and other phrases or keywords derived therefrom painstaking strung together. www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 20 ("Kalahari" or "Botswana" or spellbinding “Southern Africa Savanna”) and “Global Warming” or “Climate Change” or “Climate Change Variability” and (“Woody Plants” or “Trees” or “Shrubs” or “Vegetation”) and “Distribution” or “Range Shift” or “Species Occurrence” and (“Phenology” or “Flowering Time” or “Leafing Date” or “Length of Time Growing”). Search queries were refined and search results made more specific using Boolean operators (AND, OR) along with retrenchment symbols ("phenology") to widen search results and accommodate spelling variations. In addition to database searches, manually relevant journals (Global Change Biology, Ecology, Journal of Biogeography, African Journal of Ecology) as well as conference proceedings (the International Biogeography Society, the Ecological Society of America) were used to find any studies which were likely omitted by electronic searches. Reference lists of the studies which were part of the analysis were also examined in order to find more relevant studies using the ‘snowballing’ technique (Wohlin, 2014). In order to verify the completeness of the search strategy, we reached out to Kalahari ecology and climate change experts to find any unpublished or ongoing research relevant to this meta-analysis which may have been overlooked. Inclusion and Exclusion Criteria The studies included in the meta-analysis met the additional criteria: Focus: The study examined the influence of climate change (or associated environmental changes) on the distribution or phenology of woody plant species in the Kalahari ecosystem, Botswana, and studies which were more concerned with other elements (land use change, herbivory) were left out unless they also specifically focused on the impacts of climate change. Empirical: The research incorporates original empirical data in measuring the impact of climate change. It includes observational (monitoring plant phenology), experimental (climate change), or derived (species distribution models) data. Conceptual papers, literature reviews, and purely theoretical modelling studies were not included. Woody Plants: The research restricted to the trees and shrubs that Kalahari ecosystem contains. Studies that dealt with herbaceous or agricultural crops were removed. Climate Change Related: The study and the research have to directly assess the change in climate change associated woody plant species in relation to the variables (temperature, precipitation, CO2, etc.). Quantitative Data: The study provided data to determine the effect size for meta-analysis (means, standard deviations, sample sizes, and correlation coefficients). Studies that provided only a qualitative description of climate change impacts were removed. Publication Date: The study was conducted between January 2020 to December 2024. Language: The study is in English. Items such as framework, methodology, data, results and conclusions were provided in predetermined meticulous criteria defined for inclusion, and exclusion stems from assessed and evaluated as relevant studies in whole from abstracts, and abstracts alone, from pools of entire studies from defined data sets. Pickup and Review of Bibliography not determined: Of these acts, planning, and dedicating time structure critical, most of which are of little to no funding. Selection of pertaining studies for review were in association with PRISMA guidelines, which documents composed by the authors of the research are known as, and as such followed steps. To Review the Entire Findings: For these deems, a target set of research deems are marking of focal relevance, and are in undoubtable focus of review, with the inclusion of valuable data to encompass with these studies. Disagreement Resolution Reviewer disagreements were addressed through discussion until a consensus was reached. In situations where consensus was not possible, a third reviewer, a senior professor with a www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 21 specialization in meta-analysis, made the final decisions. To reduce selection bias in the studies, we blinded the reviewers to the authors and affiliations of the studies under review. This was to ensure that the decisions made about inclusion were based on the scientific value of the research and not on bias about the authors or the affiliated institutions. To record the number of studies identified, screened, evaluated for inclusion, and then added to the meta-analysis, a PRISMA flow diagram (Moher et al., 2009) was used (Figure 1). The PRISMA flow diagram offers a clear, systematic guide to the steps followed in the selection of studies, thus ensuring that the metaanalysis can be reproduced and verified. Figure 1. PRISMA Flow Diagram Data Extraction Each included study was analyzed using a prepared data extraction form with a variety of fields for capturing pertinent information. The form was for proofing and was simplified so that group members could better use the form and capture all important data. Some key data elements extracted were: Characteristics of the Study: Authors’ names, year of publication, and title of the study, Place of the study, in terms of coordinates and height, Type of study; observational, experimental or modeled, sample size, Data collection techniques/strategies; field surveying, remote sensing, manipulating lab climate, and climate manipulation. Characteristics of the Species: Scientific and common names of the woody plant species, Functional traits, uplift drought tolerance, plant growth form, and seed dispersal mechanisms, and The Species' conservation status, using the IUCN Red List category. Climate Variables: The measured or modeled climate variables; temperature, precipitation, solar radiation, and CO2 concentration, the temporal scale of climate data, which could be daily, monthly, or yearly and The source of climate data, such as weather stations or climate models. Distribution Data: The species distribution range, the distribution latitude of the leading edge, and the elevation of the leading edge. Assessment techniques of the species distribution changes over time; species distribution models and field survey techniques. Phenology Data: Plant phenology changes, the flowering date, and leafing date, and the length of the growing season. Techniques of assessment include field observations and remote sensing. Effect Sizes: Data were extracted or computed for use in determining effect sizes for the purpose of conducting meta-analysis. The specific effect sizes measures used were determined by the nature of the data each study reported. Some of the effect size measures employed were: Cohen's d: Used for measuring the means of two groups (such as flowering dates in the control vs. treatment groups). Pearson's r: Used for assessing the degree of association between two variables (the temperature and the flowering date). Odds ratios: Used for assessing the odds of an event occurring in two different groups (the presence of a given species in a particular locality under certain climate conditions). www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 22 The extracted data from each study were independently corroborated by two reviewers. Conflicts were settled based on discussions and compromise. A detailed codebook was created to maintain uniformity during the data extraction process. For the purpose of maintaining the accuracy of the data extraction process, a double-data-extraction technique was employed whereby two independent reviewers carried out data extraction for each study. The two reviewers were able to arrive at a consensus during discussions and disagreements were settled. This helped in reducing the chances of data extraction mistakes and increasing the reliability of the meta-analysis. Data Analysis Analysis of the data employed both qualitative and quantitative approaches to assess the impacts of climate change on the distribution and phenology of woody plant species in the Kalahari. Qualitative Synthesis: The qualitative findings of the studies included in the analysis were summarized using a narrative synthesis with a focus on the major themes and mechanisms associated with the responses of species to climate change. Quantitative Meta Analysis: Statistical metaanalysis was conducted in the R environment (R Core Team 2023) using the metafor package (Viechtbauer 2010). Calculation of Effect Size: Effect sizes were computed for each study using specific formulas relative to the data types presented. Effect sizes were brought to a common metric (Hedge's g) for easier comparison. Hedges’ g was the preferred measure of effect size in this case because it is a mean difference effect size that is adjusted for sample size bias and thus, is appropriate for meta-analysis with sample size varying studies. Meta-Analytic Models: In estimating the overall impact of climate change on species distribution and phenology, both fixed-effects and sclerd meta-analytic models were employed. With heterogeneity low (I2 < 25%), the fixed-effects model was employed, on the assumption that all studies estimated the same true effect. A random-effects model was employed when heterogeneity was moderate to high (I2 > 25\%) and accounted for differences among studies due to differences in methodology, species, and location. In the random-effects models, the restricted maximum likelihood (REML) estimator was used for estimating the betweenstudy variance. The REML estimator is the most widely used estimator for the between-study variance component in random-effects models and is more robust against outliers than other estimators. Subgroup Analysis: To assess the impact of some variables on the effect sizes, subgroup analyses were warranted. Traits of species (drought tolerance, growth form), habitat constituents (type of soil, quantity of water), and climate indices (temperature, rainfall) served as the basis for establishing subgroups. To investigate how the effects of climate change on the distribution and phenology of plants with differing species traits, habitat, and climate traits, more refined analyses were needed, and they were termed tiered analyses. Meta-Regression: The metas analyses conducted meta-regression to explore relationships between variables under the study (sample size, study quality) and derived effect sizes. This facilitated the determination of possible moderators of the impact of climate change on woody plant species. Meta-regression analyses sought to uncover potential moderators of climate change impact on the distribution and phenology of plants. Heterogeneity Assessment: The evaluation of variability among different studies was based on the Q statistic and the I2 statistic. The Q statistic assesses whether the differences between studies were larger than would be expected by chance. The I2 statistic refers to the proportion of the total variability among studies that is heterogeneity. In assessing the heterogeneity among the various studies, the Q statistic and I2 statistic were applied. If the value of the Q statistic is significant and the I2 value is high, there is considerable variability, or heterogeneity, among the studies. Bias Related To Publication Assessment: Publication Bias originates from funneloved , www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 23 Egger’s test, & Begg’s test, and funnel graphs. Plotting funnels of graphs determines biases by showing relationships between the effect size of the evaluation and the standard size errors. These errors, for instance, Egger’s test and Begg’s test, calculate asymmetry of the funnel graph. The trim and fill method calculates estimates of unaccounted for studies on biases of published works, and modifies the effect size of estimates (Duval & Tweedie, 2000). It was also assessed why studies that show results which are significant are works while studies that show non-significant conclusions are never published. They called this effect, the publication bias. Results This part of the paper consists of results from the meta analysis, presented in the paper in the clearest, brief, and objective manner possible. The most important results pertaining to the analysis will be presented within tables and figures. The emphasis will be on size of effect, intervals of confidence, and heterogeneity elements. Study Selection In total, 1542 records were created from the initial database searches such as (Web of Science: 523, Scopus: 612, Google Scholar: 407). After the duplication deletion (n=312), 1230 titles and abstracts were scanned. Using the set inclusion criteria, 98 full-text articles were reviewed. Out of this number, 35 fulfilled the criteria and were selected for the meta-analysis (Figure 1). Most frequent reasons for exclusion were the absence of empirical evidence, concentrated on nonwoody plant species, or missing pertinent climate change elements. The study selection process, as shown in the PRISMA flow diagram (Figure 1), facilitates clear, organizational criteria for the research inclusion in the meta-analysis. Characteristics of the Studies The meta-analysis consists of 35 different studies of which the bulk were conducted in Botswana (n=18) and Namibia (n=12) and the remainder in South Africa (n=5) focusing on various parts of the Kalahari ecosystem. The most common studies (n=20) were the observational studies which involved the monitoring of phenology and plant distribution. This was followed by species distribution modelling studies (n=10) and experimental studies on climate change (n=5). Table 1 summarizes the most important features of these studies. The variety in the climate change studies emphasize the different consequences this phenomenon has on plant communities and the different techniques that are used to analyze this. Table 1. Characteristics of the Studies Study ID Country Study Type Species Focus Sample Size Years Covered Notes 1 Botswana Observational Acacia spp. 120 2005–2015 Long-term monitoring 2 Namibia SDM Mopane trees 180 2008–2018 Climate suitability modeling 3 South Africa Experimental Climate Manipulation Shrubs 50 2012–2017 Rainfall exclusion experiment 4 Botswana Observational Woody shrubs 150 2006–2016 Phenology and distribution tracking 35 Namibia SDM Mixed woody species 200 2010–2020 Projected range shifts Meta Analysis Results: Distribution (Range Shifts) As for the Kalahari region, climate change did have an impact on the distribution of the region’s woody plants with an overall impact centered around the range of Hedges’ g=0.42. Change in the climate within the region had a comparatively moderate impact on the www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 30 ecosystem to protect and reduce climate change impacts on the woody plant community. These measures should be responsive to the climate change impacts and the species-specific loss, and should be incorporated into comprehensive land management and climate change adaptation frameworks. Assessments of Vulnerability Unique to Each Species One of the most important initial steps is the creation of assessments that determine the climate vulnerability of a species in order to pinpoint the most at-risk populations. These assessments must include the range of species distribution, functioning and phenology, functional traits, genetic variation, and the overall ability to adapt to changes. These assessments must also include climate-change projections at the appropriate scale, downscaled to understand the threats that different populations are likely to face. Migration With Assistance For some species, having to remain within a given range and naturally not being able to migrate due to range discontinuities, have what is called dispersal limitations, and, therefore, may have what is called assisted migration as a possible conservation strategy. Assisted migration is the movement of individuals from populations that are in decline to more suitable habitats outside the current range of the population (Richardson et al., 2009). Realistically, however, assisted migration is a highly controversial strategy and in the wake of careful risk assessment, its possible ecological impacts must also be considered. Habitat Restoration and Wildlife Corridors The ability to facilitate and restore connectivity between habitats is necessary for the movement of species and the resilience of ecosystems. Corridors restore and allow for movement among fragmented habitats which enables wildlife to pursue their niche conditions as the climate changes. Restoration should focus on ensuring structural and functional habitat diversity and climate resilient habitats to support wide ranging species. Configuration of Land Use for Sustainable Management Resiliency of plant communities to climate changes can be accompanied with sustainable land use systems. Moderating overgrazing, soil erosion, and invasives are some of the sustainable practices for land use. Sustainable land use systems will also enhance water availability, which is one of the most important constraints for plant growth in the Kalahari. Management of Conservation Areas Conserved regions are important for the protection of species and diversity, while also reducing the impacts of climate changes. Nonetheless, protected area management plans need to be revised to include relevant aspects of climate change. These include Zone of influence boundaries revision for protected areas and species change range, active climate change management, and promotion of climate responsive touristic activities. Community Engagement Listening to the community is the most vital component of conservation. These projects have to be designed with the input of the community members as they have cultural practices and realities to deal with. Community conservation projects can encourage the sustainable use of the land and lessen the impact of people on the vegetation. Monitoring and Evaluation Active monitoring and evaluating the success of conservation and the suitability of management continues to be essential. Monitoring should include the routine evaluation of the distribution of species, changes to their abundance, time of year, and the overall condition of the species’ habitat. Collected data should inform the management cycle to make sure it is optimised for the desired outcome. Policy Interventions Policymaking on the other hand, should be in to implement practices for both the improvement of climate and adaptation. Focus on the Kalahari and implement policy on: www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 31 • Reduce the Kalahari Emission: Joint efforts on the Kalahari GHG is a central focus for impact, climate systemic efforts for improvement should be integrated. • More Invested Attention to the Change of the Kalahari: More attention in impactisation on the Change of the Kalahari is needed, framing research should be a priority to adapt policies in practice. Intergrating Climate Change Factors into Land Planning: Land use managers should incorporate climate change into all facets of land use planning, including protected area management, agriculture, and urban planning. Supporting Sustainable Livelihoods: Providing local communities with opportunities for sustainable livelihoods will curb their dependence on natural resources. Contribution/Value-Add The works of this analysis hold immense significance towards scientific research, and practice especially concerning conservation work. Quantitative Synthesis: There now exists a comprehensive quantitative synthesis of the research concerning the effects of climate change on certain ‘keystone’ woody species within the Kalahari ecosystem. this synthesis is one of the most up-to-date and comprehensive assessments of climate change impacts, owing to a more reliable aggregation of research output than currently available peer-reviewed studies. Identification of Key Drivers: The effects of climate change on biota, particularly key woody species, and the critical factors that drive the response of such biota to climate change such as periods of rainfall, and the seasonality of rainfall, as well as the depth and tenacity of the root systems. Assessment of Publication Bias: The research works on climate change and publication bias works on the fiction that most climate change research works on the assumption that the net effects of climate change are unabated for all ecosystems—this study works within a more realistic frame and, in the process, provides an alternative assessment of the net effects of climate change. Practical Recommendations: There exists a range of research works within these boundaries that provide a set of guidelines for practitioners, researchers, and policymakers concerning more sophisticated species-centered conservation, animal and plant assisted migration, land use, and land rehabilitation. Theoretical Framework: The study adds to the body of ecological theory by providing a framework that explains the results of this research, and that directs subsequent research. In summary, this meta-analysis addresses gaps within the Kalahari ecosystem about the effects of climate change, as well as providing the researchers, practitioners, and policy-makers with useful information on how best to mitigate the change. This meta-analysis covers the major problems with species change, and the extent of the changes which will assist other researchers, and policy-makers devise an applicable strategy based on evidence which will improve the overall understanding of Kalahari ecosystems and climate change. New Directions for Research This meta-analysis does highlight some aspects of climate change such as how it can affect the future and what strategies can be put into place for better conservation. It does, however, state conservation strategies can be put into place, what it fails to highlight is the changes in human behavior, and predicting future human and ecosystem interactions. Continuous Assessment Exercises: Continuous exercises are crucial to evaluate the climate interactions and biodiversity consequences to understand the patterns of variation in the ecosystem. Population studies: Population studies are required to evaluate the core species, the population levels, the survival prospects, and the age groups in relation to the climate changes and density changes. Ecological and Physiological studies: Ecological and Physiological studies are required to understand about the influence level of climate, www.ejtas.com European Journal of Theoretical and Applied Sciences (ISSN 2786-7447) 2025 | Volume 3 | Number 6 32 how the species of the population clusters, and how the species get dispersed. Modelling studies: Modelling studies are required to evaluate the potential level of inbreeding, and what type of adaptive strategies are required for the species in relation to the local climate and ecosystem. Socio-Ecological Studies: Socio-ecological studies will enable understanding of the human aspects of climate change and develop conservation methods that are both socially viable and environmentally sound. Conclusion The Kalahari ecosystem is an extremely one of a kind and semi-arid savanna that is being strained unlike any other ecosystem due to climate change. This meta-analysis demonstrates that climate change is a major driver of both shifts in the distribution and the timing of flowering or fruiting for several species of trees and shrubs. Ecosystems functioning may be disrupted, biodiversity may be lost, and the peoples that depend on the region may suffer greatly. The problem is one that calls for active involvement of researchers, conservationists, policymakers, and local people. The proactive conservation steps, combined with the sustainable land use strategies and climate change mitigation in land use planning, will improve the resilience and sustainability of the Kalahari ecosystem. It is then vitality important to understand that ecosystem research and sustained observation are crucial for informing management action and conservation policies in a world of changing climate. The rest of the world and those who are reliant on the Kalahari will be deciding the fate of the ecosystem. This is only possible with collaboration and committing towards a common goal. References Ackerly, D. D., Loarie, S. R., Cornwell, W. K., Weiss, S. B., Hamilton, H., Branciforte, R., & Kraft, N. J. B. (2010). Niche conservatism defines the geographic range limits of plant species. 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