Conservation Biology Research Articles

Overlap between priority conservation areas and natural assets appeals to a shared responsibility for global primate conservation

Expanding protected areas (PAs) coverage to match countries’ conservation responsibility is vital to stemming global biodiversity loss. Uneven biodiversity distribution and conservation responsibility among countries pose challenges to the implementation of conservation targets, and currently diminish conservation effectiveness. Using primates as a global model, we evaluated the conservation responsibility of countries to assess if their PA coverage adequately meets their conservation responsibility. We quantified spatial national responsibility for primate species conservation in each country from their range size of priority conservation areas (PCAs) and protected areas coverage on PCAs. We identified the high-responsibility countries for global primate conservation as countries that held > 1 % of global PCAs. We paid particular attention to the circumstances associated with PCAs in the least developed countries, especially the overlap between PCAs and the areas containing natural assets (natural assets areas). Seventeen countries were identified as high-responsibility countries that in total covered 84 % area of global PCAs. Current protected areas only covered less than 50 % of PCAs for fifteen of these high-responsibility countries. Among these fifteen countries, four countries (DR Congo, PA coverage: 19 %; Myanmar, 9 %; Madagascar, 29 %; Laos, 22 %) were the least developed countries. Most existing PCAs (95 %; SD 6 %) in these 17 countries are located within natural assets areas, which creates tension between primate conservation and local development. Global primate conservation is a shared responsibility among the international community. Developing countries have greater responsibility than most because of the overlapping of their PCAs with natural assets areas. For developing countries to fulfill their conservation responsibilities requires international conservation resources (funding support and cooperation). Protected areas expansion has to be matched with a realizable target for each country to avoid crippling conflicts between conservation and local development. Community-based management models, including other effective area-based conservation measures, may reduce potential conflict and improve conservation effectiveness.

Changes in Wuhan’s Carbon Stocks and Their Spatial Distributions in 2050 under Multiple Projection Scenarios

Urbanization in the 21st century has reshaped carbon stock distributions through the expansion of cities. By using the PLUS and InVEST models, this study predicts land use and carbon stocks in Wuhan in 2050 using three future scenarios. Employing local Moran’s I, we analyze carbon stock clustering under these scenarios, and the Getis–Ord Gi* statistic identifies regions with significantly higher and lower carbon-stock changes between 2020 and 2050. The results reveal a 2.5 Tg decline in Wuhan’s carbon stock from 2000 to 2020, concentrated from the central to the outer city areas along the Yangtze River. By 2050, the ecological conservation scenario produced the highest carbon stock prediction, 77.48 Tg, while the economic development scenario produced the lowest, 76.4 Tg. High-carbon stock-change areas cluster in the north and south, contrasting with low-change area concentrations in the center. This research provides practical insights that support Wuhan’s sustainable development and carbon neutrality goals.

The genetic consequences of population marginality: A case study in maritime pine

AbstractAimMarginal tree populations, either those located at the edges of the species' range or in suboptimal environments, are often a valuable genetic resource for biological conservation. However, there is a lack of knowledge about the genetic consequences of population marginality, estimated across entire species' ranges. Our study addresses this gap by providing information about several genetic indicators and their variability in marginal and core populations identified using quantitative marginality indices.LocationSouthwestern Europe and North Africa.MethodsUsing 10,185 SNPs across 82 populations of maritime pine (Pinus pinaster Ait.), a widespread conifer characterised by a fragmented range, we modelled the relationship of seven genetic indicators potentially related to population evolutionary resilience, namely genetic diversity (based on both all SNPs and outlier SNPs), inbreeding, genetic differentiation, recessive genetic load and genomic offset, with population geographical, demo‐historical and ecological marginality (as estimated by nine quantitative indices). Models were constructed for both regional (introducing gene pool as a random factor) and range‐wide spatial scales.ResultsWe showed a trend towards decreasing overall genetic diversity and increasing differentiation with geographic marginality, supporting the centre‐periphery hypothesis (CPH). However, we found no correlation between population inbreeding and marginality, while geographically marginal populations had a lower recessive genetic load (only models without the gene pool effect). Ecologically marginal populations had a higher genomic offset, suggesting higher maladaptation to future climate, albeit some of these populations also had high genetic diversity for climate outliers.Main ConclusionsOverall genetic diversity (but not outlier‐based estimates) and differentiation patterns support the CPH. Ecologically marginal populations and those at the southern edge could be more vulnerable to climate change due to higher climate maladaptation, as predicted by genomic offsets, and/or lower potentially adaptive genetic diversity. This risk is exacerbated by typically small effective population sizes and increasing human impact in marginal populations.

The US Endangered Species Act and acceptable risk

The fundamental criterion for listing or delisting species under the United States Endangered Species Act (ESA) is acceptable extinction risk. But what is the meaning of “acceptable risk”? This concept has received little attention in conservation biology, and hence, the purpose of this paper is to explain acceptable risk within the context of the ESA. All complex environmental policy decisions involve trade-offs, and hence, choosing one policy from several policy options entails a comparison of the benefits, costs, and risks of all options. Acceptable-risk problems are decision problems requiring a choice among different policy options, and an acceptable risk is defined as the risk associated with the chosen policy. In general, people will accept the risk imposed by a particular policy when that policy yields sufficient net benefits. The ESA, its legislative history, and implementing regulations clearly state that species listing determinations must be based solely on science and “without reference to possible economic or other impacts” caused by the listing of that species. If economic considerations are prohibited from influencing listing decisions, then risk reduction is not constrained by cost, and therefore, the only rational choice for acceptable extinction risk is zero risk. This outcome, known as a “stopping-point problem”, is absurd, and consequently, federal agencies responsible for listing determinations are forced to issue opaque decisions that obscure their true rationale, which in turn, lead to inconsistency and improper political influence. Illustrations of acceptable risk in null hypothesis tests, the United States Clean Air Act, and minimum viable population size are also presented.

Conservation Status of The Military Frog (Atelopus Balios) In the San Miguel Canton Naranjal Community

The present research focused on the conservation status of Atelopus balios, a species classified in the red list in danger of extinction, the destruction of its natural habitat is the main cause not only of the mentioned species but of all the amphibian fauna existing in the locality intervening in its development and reproduction. Three priority conservation areas were monitored within the locality, all this could be carried out with Geographic Information Systems, capturing the coordinates of identification of species records, and thus be able to interpret each of the data, where more specimens were found establishing areas of interest for the conservation of the species where measures for sustainable management should be implemented.

Unravelling the novel sex determination genotype with 'ZY' and a distinctive 2.15-2.95 Mb inversion among poplar species through haplotype-resolved genome assembly and comparative genomics analysis.

Populus tomentosa, an indigenous tree species, is widely distributed and cultivated over 1,000,000 km2 in China, contributing significantly to forest production, ecological conservation and urban-rural greening. Although a reference genome is available for P. tomentosa, the intricate interspecific hybrid origins, chromosome structural variations (SVs) and sex determination mechanisms remain confusion and unclear due to its broad and even overlapping geographical distribution, extensive morphological variations and cross infiltration among white poplar species. We conducted a haplotype-resolved de novo assembly of P. tomentosa elite individual GM107, which comprises subgenomes a and b with a total genome size of 714.9 Mb. We then analysed the formation of hybrid species and the phylogenetic evolution and sex differentiation across the entire genus. Phylogenomic analyses suggested that GM107 likely originated from a hybridisation event between P. alba (♀) and P. davidiana (♂) which diverged at approximately 3.8 Mya. A total of 1551 chromosome SVs were identified between the two subgenomes. More noteworthily, a distinctive inversion structure spanning 2.15-2.95 Mb was unveiled among Populus, Tacamahaca, Turaga, Aigeiros poplar species and Salix, highlighting a unique evolutionary feature. Intriguingly, a novel sex genotype of the ZY type, which represents a crossover between XY and ZW systems, was identified and confirmed through both natural and artificial hybrids populations. These novel insights offer significant theoretical value for the study of the species' evolutionary origins and serve as a valuable resource for ecological genetics and forest biotechnology.

Population structure of Dugong dugon across the Indo-Pacific revealed by historical mitogenomes.

Sirenia, an iconic marine taxon with a tropical and subtropical worldwide distribution, face an uncertain future. All species are designated 'Vulnerable' to extinction by the IUCN. Nonetheless, a comprehensive understanding of geographic structuring across the global range is lacking, impeding our ability to highlight particularly vulnerable populations for conservation priority. Here, we use ancient DNA to investigate dugong (Dugong dugon) population structure, analysing 56 mitogenomes from specimens comprising the known historical range. Our results reveal geographically structured and distinct monophyletic clades characterized by contrasting evolutionary histories. We observe deep-rooted and divergent lineages in the East (Indo-Pacific) and obtain new evidence for the relatively recent dispersal of dugongs into the western Indian Ocean. All populations are significantly differentiated from each other with western populations having approximately 10-fold lower levels of genetic variation than eastern Indo-Pacific populations. Additionally, we find a significant temporal loss of genetic diversity in western Indian Ocean dugongs since the mid-twentieth century, as well as a decline in population size beginning approximately 1000 years ago. Our results add to the growing body of evidence that dugong populations are becoming ever more susceptible to ongoing human action and global climate change.

Inferring the extinction risk of marine fish to inform global conservation priorities.

While extinction risk categorization is fundamental for building robust conservation planning for marine fishes, empirical data on occurrence and vulnerability to disturbances are still lacking for most marine teleost fish species, preventing the assessment of their International Union for the Conservation of Nature (IUCN) status. In this article, we predicted the IUCN status of marine fishes based on two machine learning algorithms, trained with available species occurrences, biological traits, taxonomy, and human uses. We found that extinction risk for marine fish species is higher than initially estimated by the IUCN, increasing from 2.5% to 12.7%. Species predicted as Threatened were mainly characterized by a small geographic range, a relatively large body size, and a low growth rate. Hotspots of predicted Threatened species peaked mainly in the South China Sea, the Philippine Sea, the Celebes Sea, the west coast Australia and North America. We also explored the consequences of including these predicted species' IUCN status in the prioritization of marine protected areas through conservation planning. We found a marked increase in prioritization ranks for subpolar and polar regions despite their low species richness. We suggest to integrate multifactorial ensemble learning to assess species extinction risk and offer a more complete view of endangered taxonomic groups to ultimately reach global conservation targets like the extending coverage of protected areas where species are the most vulnerable.

Microhabitat and seasonal influence on bess beetle (Coleoptera: Passalidae) assemblage in Altitudinal Atlantic Forest

AbstractUnderstanding the spatiotemporal distribution of diversity has been a significant challenge in the field of conservation biology. Presently, there exists a limited understanding of the spatial distribution of passalid beetles within decomposing logs, as well as their distribution in microhabitats such as the cortex, heartwood and trunk–soil interface. Moreover, there is a scarcity of studies that delve into the temporal distribution patterns of passalid beetles. We evaluate the effect of seasons of the year and microhabitats on the distribution of passalid in an Altitudinal Atlantic Forest. More specifically, the effects of the period of the year and microhabitats were analysed on an assemblage scale and population structure scale. Collections were actively conducted monthly, during dry and rainy seasons, and distinct microhabitats of logs (tree cortex, heartwood and trunk–soil interface) were sampled. We discovered passalid galleries within 235 logs, housing a total of 785 individuals representing nine species across six genera and two tribes. Within the three examined microhabitats, the heartwood and cortex harboured the majority of individuals. In contrast, the trunk–soil interface microhabitat displayed reduced diversity and abundance and the absence of indicator species, exhibiting a distinct community structure compared with the others. The dry season stood out with a greater number of individuals, underscoring the influence of precipitation on passalid activity in this study. Our study contributes to understanding the ecological dynamics of these insects and evaluating their resilience to current landscape transformations on the planet.

The complex effects of modern oncogenic environments on the fitness, evolution and conservation of wildlife species.

Growing evidence indicates that human activities are causing cancer rates to rise in both human and wildlife populations. This is due to the inability of ancestral anti-cancer defences to cope with modern environmental risks. The evolutionary mismatch between modern oncogenic risks and evolved cancer defences has far-reaching effects on various biological aspects at different timeframes, demanding a comprehensive study of the biology and evolutionary ecology of the affected species. Firstly, the increased activation of anti-cancer defences leads to excessive energy expenditure, affecting other biological functions and potentially causing health issues like autoimmune diseases. Secondly, tumorigenesis itself can impact important fitness-related parameters such as competitiveness, predator evasion, resistance to parasites, and dispersal capacity. Thirdly, rising cancer risks can influence the species' life-history traits, often favoring early reproduction to offset fitness costs associated with cancer. However, this strategy has its limits, and it may not ensure the sustainability of the species if cancer risks continue to rise. Lastly, some species may evolve additional anti-cancer defences, with uncertain consequences for their biology and future evolutionary path. In summary, we argue that the effects of increased exposure to cancer-causing substances on wildlife are complex, ranging from immediate responses to long-term evolutionary changes. Understanding these processes, especially in the context of conservation biology, is urgently needed.

Scale effect of landscape characteristics on undergrowth vegetation variance with different ecological traits

Herbaceous understory vegetation plays a significant role in temperate forested ecosystems, with its diversity strongly dependent on both local and landscape conditions. However, the contribution of these factors across different spatial scales (e.g., scale effect) remains inadequately understood. The objective of this study was to determine the most important landscape and local characteristics influencing the species richness of the herb layer. We surveyed and sampled 53 sites in a mountainous forest within the Baihuashan National Nature Reserve of Beijing. Using generalized linear models, we investigated the simultaneous effect of local (e.g. tree density, average tree height, and cover of tree, shrub, and ground vegetation) and landscape (e.g. Area-weighted Mean Patch Size, Area-weighted Mean Euclidean Nearest Neighbor Distance, Area-weighted Mean Fractal Dimension Index, forest area, and shrubbery area) variables on the richness of species in the understory herb layer. Variation partitioning was used to examine the individual contribution of local and landscape variables. Our results identified 366 plant species from 95 families across 53 sampling sites. Significant differences in species richness were found among life forms, seed dispersal types, and habitat preferences (P < 0.001). Parsimonious models indicated that combining local and landscape factors at a 2 km scale explained the most variation in phanerophytes (R2 = 0.658). Locally, average tree height significantly influenced the species richness of biotic dispersal, phanerophytes, and geophytes. At the landscape level, variables such as the Area-weighted Mean Fractal Dimension Index and farmland area significantly impacted plant community traits across different scales. Understanding these effects is crucial for developing effective sustainable forest ecosystem management strategies and for establishing robust ecological conservation policies.

Ecological zoning and ecosystem management based on landscape ecological risk and ecosystem services: A case study in the Wuling Mountain Area

Land use and cover changes have substantially altered surface landscape patterns, resulting in landscape ecological risk (LER) and jeopardizing the continued supply of ecosystem services (ES). Although ES and LER are positive and negative aspects of ecological security representation, respectively, the spatiotemporal mechanism of their interaction still needs to be further clarified. This study focused on the Wuling Mountain Area (WMA), a critical ecological functional zone. First, multi-source data and multi-models were used to evaluate LER and ES and analyze their spatiotemporal characteristics. Subsequently, a geographically and temporally weighted regression model was applied to uncover the spatiotemporal heterogeneity of the impacts of LER on various ES. Finally, ecological zones were delineated based on the LER-ES quadrant, a driving force analysis was conducted, and ecological management strategies are proposed. The main results are as follows: (1) LER and various ES showed overall decreasing and increasing trends, respectively. (2) Except for water yield, the impact of LER on various ES showed clear spatiotemporal non-stationarity, with a significant negative impact, which was most pronounced for habitat quality. (3) The WMA was divided into four ecological zones: ecological risk prevention zone, ecological conservation zone, ES enhancement zone, and ecological reshaping zone. Elevation, normalized difference vegetation index, and human footprint were identified as the main drivers of ecological zoning. This research lays a solid foundation for in-depth understanding of the impacts of LER on ES. The proposed zoning scheme provides strong support for the ecologically sustainable development of the WMA.

Insights into nitrogen biogeochemical cycling in mangrove wetland from Genome-Resolved metagenomic sequencing

The critical role of nitrogen (N) in sustaining the vitality of mangrove wetlands is widely recognized, yet research elucidating complex microbiome structures and functional genes driving N biogeochemical cycles are markedly limited. This study leverages high-throughput and metagenomic sequencing to investigate N biogeochemical cycling from the Dongzhai Harbor mangrove wetland. Results reveal that Proteobacteria (29.95–49.26%), Chloroflexi (15.68–35.33%), and Acidobacteria (5.18–12.46%) are the predominant phyla, with Deltaproteobacteria (3.71–7.95%), Gammaproteobacteria (0.83–8.73%), and Alphaproteobacteria (1.73–14.13%) leading at the order level. Microbial diversity and the prevalence of functional genes diminish with increasing sediment depth, indicating that N transformation predominantly occurs in surface sediments. The identified N metabolic pathways in mangrove sediments encompass N fixation (nifD, nifK, nifH genes), nitrification (amoA, amoB, amoC, hao, nxrA and nxrB genes), denitrification (narG, nirK, nirS, norB and nosZ genes), dissimilatory nitrate reduction to ammonium (hzo、hzsA and hzsB genes), and organic N mineralization (gdhA and ureC genes). Organic N mineralization and N fixation are most pronounced in mangrove sediments, with N fixation exhibiting greater intensity in the mangrove than mudflat zone. Salinity, TOC, TN, and SO42- predominantly foster N cycling facilitated by microbial activities, while Fe appears to impede it. These insights offer a scientific foundation for the ecological restoration and conservation of mangrove wetlands.

Significance of AI-assisted techniques for epiphyte plant monitoring and identification from drone images

Monitoring forest canopies is vital for ecological studies, particularly for assessing epiphytes in rain forest ecosystems. Traditional methods for studying epiphytes, such as climbing trees and building observation structures, are labor, cost intensive and risky. Unmanned Aerial Vehicles (UAVs) have emerged as a valuable tool in this domain, offering botanists a safer and more cost-effective means to collect data. This study leverages AI-assisted techniques to enhance the identification and mapping of epiphytes using UAV imagery. The primary objective of this research is to evaluate the effectiveness of AI-assisted methods compared to traditional approaches in segmenting/identifying epiphytes from UAV images collected in a reserve forest in Costa Rica. Specifically, the study investigates whether Deep Learning (DL) models can accurately identify epiphytes during complex backgrounds, even with a limited dataset of varying image quality. Systematically, this study compares three traditional image segmentation methods Auto Cluster, Watershed, and Level Set with two DL-based segmentation networks: the UNet and the Vision Transformer-based TransUNet. Results obtained from this study indicate that traditional methods struggle with the complexity of vegetation backgrounds and variability in target characteristics. Epiphyte identification results were quantitatively evaluated using the Jaccard score. Among traditional methods, Watershed scored 0.10, Auto Cluster 0.13, and Level Set failed to identify the target. In contrast, AI-assisted models performed better, with UNet scoring 0.60 and TransUNet 0.65. These results highlight the potential of DL approaches to improve the accuracy and efficiency of epiphyte identification and mapping, advancing ecological research and conservation.

The Taxonomic Diversity and Conservation Status of Endemic Plant Species in the Gangetic Plains of Prayagraj

Abstract: This study investigates the taxonomic diversity and conservation status of endemic plant species in the Gangetic plains of Prayagraj. Field surveys and literature review identified 125 endemic plant species, distributed across 45 families and 78 genera. Assessment of their conservation status revealed that 30% of these species are threatened, with 15% categorized as critically endangered. The primary threats to these endemic plants include habitat loss due to urbanization and agricultural expansion, fragmentation, and anthropogenic pressures such as grazing and invasive species encroachment. Conservation efforts are urgently needed to mitigate these threats and ensure the preservation of the unique flora in the Gangetic plains of Prayagraj. Priority actions include habitat preservation, restoration initiatives, and community engagement to promote sustainable land use practices. This research provides valuable insights into the conservation priorities for endemic plant species in this region, serving as a foundation for future conservation strategies and biodiversity management efforts.

The herpetofauna of the Sporades Islands (Aegean Sea, Greece): New discoveries and a review of a century of research

The Sporades are one of the most biologically important archipelagos in the Aegean Sea (Greece) and have received priority conservation over the last 50 years. However, despite numerous early efforts, its herpetofauna is only partially described, resulting in many distributional gaps that have prevented adequate understanding and management of the resident species communities. We review one century of bibliography from the Northern Sporades and combine this information with a review of museum specimens and insights from numerous extensive field surveys over the last near-decade to provide for the first time a comprehensive picture of the reptiles and amphibians of the archipelago. We report here on 26 new island records and find that the herptile communities of the region are largely derived from the herpetofauna of the nearby Thessaly mainland, with only a few introduced taxa. There is also a small but significant set of endemic taxa in the archipelago. Island species richness declines with decreasing island size and increasing duration of island isolation. Herptile communities on smaller islands are progressively nested subsets of the communities on larger islands. The presence of reptile species depends sensitively on the condition and management of native ecosystems. While non-aquatic species maintain largely healthy populations, most populations are under pressure from the combined effects of rampant tourist development, the destruction and degradation of rare wetland habitats, and the abandonment of traditional agricultural landscapes. We provide recommendations regarding sustainable management of the local reptile and amphibian populations.

Measuring museum sustainability in China: a DSR model-driven approach to empower sustainable development goals (SDGs)

In the past few years, sustainable development has undoubtedly become an essential perspective for museums. Museums have been committed to raising social awareness around ecological conservation and cultural diversity through various exhibitions, education and research projects, and public engagement. However, the concepts, approaches, and practises of “sustainability” differ across nations and regions, and there is a lack of sufficient quantitative research on sustainable development by and within museums. This article aims to establish an evaluation framework and evaluation approach for museum sustainability in China. Its framework is initially based on the DSR model, in which “D” delineates seven deeds of museum visitors, “S” characterizes the status of sustainable practises within museums, and “R” involves presenting sustainability strategies pertinent to Chinese museums by integrating Sustainable Development Goals (SDGs). A fuzzy QFD model is then used to develop an evaluation approach for analyzing the Zhejiang Natural History Museum (ZNHM)’s sustainable development strategies, using data from surveys and in-depth interviews. As a result of this study, significant opportunities for deepening sustainable practises were identified for ZNHM, which include updating the collection system, enhancing professionalism in exhibitions and educational projects, and securing funding policies. ZNHM’s sustainability efforts prioritize enhancing social awareness, and internal reforms related to social value, governance, and professional capabilities. With these foundations in place, international cooperation among museums may be the next step towards a sustainable future.

Morphology of arthropods discovered in pitchers of Nepenthes at Aceh Singkil District, Indonesia

Abstract. Tarigan MRM, Faisal M, Manalu K, Khairuna, Tambunan EPS, Rahmadina, Asy’ari H, Ritonga YE. 2024. Morphology of arthropods discovered in pitchers of Nepenthes at Aceh Singkil District, Indonesia. Biodiversitas 25: 2888-2900. Nepenthes plants create unique microhabitats and are home to diverse arthropod communities. These plants, known for their complex and specialized structures, attract various species of arthropods and contribute to the region's biodiversity. The study of arthropod morphology is critical to understanding the complex interactions within these microhabitats as well as broader ecosystem dynamics. Although this plant has great ecological importance and conservation significance, detailed morphological studies of the arthropods living on it are still rare. This study aimed to identify the families of arthropods trapped in the upper and lower pitchers of Nepenthes. This study used descriptive methods to reveal the morphology of arthropods found in Nepenthes pitchers in Aceh Singkil District, Indonesia. Arthropods were obtained from the upper and lower pitchers of N. ampullaria, N. gracilis, N. mirabilis, N. rafflesiana, N. reinwardtiana, N. x hookeriana, and N. x trichocarpa. Samples were obtained through direct observations conducted between October to December 2023. The results showed the presence of arthropod families, namely Culicidae, Formicidae, Gryllidae, Calliphoridae, Coccinellidae, Curculionidae, Rhyaparochromidae, Blattellidae, Salticidae, and Araneidae. However, Culicidae and Formicidae were observed to be the most abundant and Gryllidae was observed to be the least abundant. A mutualistic symbiosis was established, in which ants used the tendrils of Nepenthes to lay eggs and collected nectar generated by the honey glands, while the egg-laying process helped in the breakdown of the pitcher. This discovery suggests that the plants provided a habitat for Culicidae and a conducive environment for Formicidae larvae. However, Araneidae, Rhyparochromidae, Salticidae, Curculionidae, and Coccinellidae are not attracted to petals and peristomes. Gryllidae and Blattellidae were present in Nepenthes pitchers as a result of their close association with the plant and UV color-trapping mechanism. The study of the morphology of arthropods found in Nepenthes pitchers has several overall implications. First, it contributes to our understanding of ecological interactions in Nepenthes plants, providing insight into predator-prey dynamics, nutrient cycling, and plant evolution. Second, it underscores the importance of Nepenthes plants as a microhabitat that supports diverse arthropod communities, and highlights the ecological role of arthropods in nutrient-poor environments. This research also informs conservation efforts, emphasizing the need to protect Nepenthes plant habitat to maintain biodiversity.

Spatial distribution of the ethnomedicinal plant Aglaonema simplex at the Sakaerat Environmental Research Station, Northeastern Thailand

Abstract. O-thong N, Tasen W, Marod D, Thinkampheang S, Phumphuang W. 2024. Spatial distribution of the ethnomedicinal plant Aglaonema simplex at the Sakaerat Environmental Research Station, Northeastern Thailand. Biodiversitas 25: 3043-3050. Aglaonema simplex Blume (Araceae) is an evergreen herbaceous plant used ornamentally and in traditional medicine. Although the usefulness of this plant has been widely studied and reported, its ecology remains poorly understood. In this study, we examined the effects of various environmental factors on the spatial distribution of A. simplex in a Dry Evergreen Forest (DEF) at the Sakaerat Environmental Research Station (SERS) in Northeastern Thailand. All individual plants were counted; their positions were recorded within a 16-ha Forest Dynamics Plot (FDP), and their distribution pattern was analyzed using Ripley's K function. The spatial distribution of A. simplex was determined using a generalized linear model that incorporated plant density and topographic and edaphic variables within the 16-ha study plot. We found a total of 11,232 A. simplex individuals with a density of 702 individuals ha-1, with a clumped distribution pattern. The modeling results showed that the spatial distribution of A. simplex was positively influenced by soil clay content, soil pH, exchangeable magnesium, and adult tree density; it was negatively influenced by sapling density and rocky outcrops. These findings contribute to the broader understanding of the ecological niche of A. simplex. They can be used to design integrated land management approaches that balance ecological conservation with economic development goals.

Shaping Baltimore’s urban forests: past insights for present-day ecology

ContextLand use history of urban forests impacts present-day soil structure, vegetation, and ecosystem function, yet is rarely documented in a way accessible to planners and land managers.ObjectivesTo (1) summarize historical land cover of present-day forest patches in Baltimore, MD, USA across land ownership categories and (2) determine whether social-ecological characteristics vary by historical land cover trajectory.MethodsUsing land cover classification derived from 1927 and 1953 aerial imagery, we summarized present-day forest cover by three land cover sequence classes: (1) Persistent forest that has remained forested since 1927, (2) Successional forest previously cleared for non-forest vegetation (including agriculture) that has since reforested, or (3) Converted forest that has regrown on previously developed areas. We then assessed present-day ownership and average canopy height of forest patches by land cover sequence class.ResultsMore than half of Baltimore City’s forest has persisted since at least 1927, 72% since 1953. About 30% has succeeded from non-forest vegetation during the past century, while 15% has reverted from previous development. A large proportion of forest converted from previous development is currently privately owned, whereas persistent and successional forest are more likely municipally-owned. Successional forest occurred on larger average parcels with the fewest number of distinct property owners per patch. Average tree canopy height was significantly greater in patches of persistent forest (mean = 18.1 m) compared to canopy height in successional and converted forest patches (16.6 m and 16.9 m, respectively).ConclusionsHistorical context is often absent from urban landscape ecology but provides information that can inform management approaches and conservation priorities with limited resources for sustaining urban natural resources. Using historical landscape analysis, urban forest patches could be further prioritized for protection by their age class and associated ecosystem characteristics.