Decrease In Population Size Research Articles

Hill-Robertson interference may bias the inference of fitness effects of new mutations in highly selfing species.

The accurate estimation of the distribution of fitness effects (DFE) of new mutations is critical for population genetic inference but remains a challenging task. While various methods have been developed for DFE inference using the site frequency spectrum of putatively neutral and selected sites, their applicability in species with diverse life history traits and complex demographic scenarios is not well understood. Selfing is common among eukaryotic species and can lead to decreased effective recombination rates, increasing the effects of selection at linked sites, including interference between selected alleles. We employ forward simulations to investigate the limitations of current DFE estimation approaches in the presence of selfing and other model violations, such as linkage, departures from semidominance, population structure, and uneven sampling. We find that distortions of the site frequency spectrum due to Hill-Robertson interference in highly selfing populations lead to mis-inference of the deleterious DFE of new mutations. Specifically, when inferring the distribution of selection coefficients, there is an overestimation of nearly neutral and strongly deleterious mutations and an underestimation of mildly deleterious mutations when interference between selected alleles is pervasive. In addition, the presence of cryptic population structure with low rates of migration and uneven sampling across subpopulations leads to the false inference of a deleterious DFE skewed towards effectively neutral/mildly deleterious mutations. Finally, the proportion of adaptive substitutions estimated at high rates of selfing is substantially overestimated. Our observations apply broadly to species and genomic regions with little/no recombination and where interference might be pervasive.

Genome-wide patterns of selection-drift variation strongly associate with organismal traits across the green plant lineage.

There are many gaps in our knowledge of how life cycle variation and organismal body architecture associate with molecular evolution. Using the diverse range of green algal body architectures and life cycle types as a test case, we hypothesize that increases in cytomorphological complexity are likely to be associated with a decrease in the effective population size, because larger-bodied organisms typically have smaller populations, resulting in increased drift. For life cycles, we expect haploid-dominant lineages to evolve under stronger selection intensity relative to diploid-dominant life cycles owing to masking of deleterious alleles in heterozygotes. We use a genome-scale data set spanning the phylogenetic diversity of green algae and phylogenetic comparative approaches to measure the relative selection intensity across different trait categories. We show stronger signatures of drift in lineages with more complex body architectures compared with unicellular lineages, which we consider to be a consequence of smaller effective population sizes of the more complex algae. Significantly higher rates of synonymous as well as nonsynonymous substitutions relative to other algal body architectures highlight that siphonous and siphonocladous body architectures, characteristic of many green seaweeds, form an interesting test case to study the potential impacts of genome redundancy on molecular evolution. Contrary to expectations, we show that levels of selection efficacy do not show a strong association with life cycle types in green algae. Taken together, our results underline the prominent impact of body architecture on the molecular evolution of green algal genomes.

The ecological hazards of profenofos revealed by soil beneficial-bacteria, plant seedlings, and plasmid nicking assays: A short-term toxicity investigation

Excessive and indiscriminate use of pesticides may adversely affect the growth and activity of both crop plants and soil microbial populations. The reported study was conducted to evaluate the toxicity of profenofos (PF; an organophosphate insecticide) using bacterial (Pseudomonas fluorescens PSB-3 and Enterobacter cloacae ZSB-8) and plant (Coriandrum sativum and Lactuca sativa L.) bioassays. PF was applied at rates of (0–100 µg mL−1) in vitro. Both bacterial strains were sensitive to PF but showed variable tolerance. Following PF exposure, cellular growth, morphology, survival, and inner membrane permeability of bacterial strains were significantly (p < 0.05) altered. Decreased population size coincided with decline in cellular respiration. The 100 µgmL−1 PF dosage imparted maximum impact on ZSB-8, inhibiting populations by 87%. PF also interfered with bacterial surface adherence (i.e., biofilm formation) in a concentration-dependent manner. Alterations in bacterial biomarker enzymatic activity and oxidative stress were also noted. PGP traits of bacterial strains were negatively and significantly (p ≤ 0.05) affected by insecticide. Under PF stress, reduction in indole-3-acetic and siderophore production followed the order: ZSB-8 > PSB-3. PF-induced phytotoxicity was confirmed via reduction in germination, seedling parameters, survival, tolerance, and vigor indices in both plant species. Additionally, PF caused distortion in morphology of root tips and root surfaces. Under CLSM, PF-exposed C. sativum and L. sativa roots exhibited increased oxidative stress. Cellular death in insecticide-treated roots was observed following staining with Evans blue dye. Insecticide concentration-dependent increase in stress markers (proline and MDA content), and antioxidant enzymatic activities in plant seedlings were observed. A dose-dependent conversion of super-coiled form of DNA to open circular in pBR-322 plasmid revealed the genotoxic potential of PF. These findings provide an understanding of toxic effects of profenofos on beneficial microbes and leafy edible vegetables, including their morphological, and cellular effects. Indeed, insecticidal applications deserve special attention due to their potential environmental hazards.

Riverscape genomics of the endangered freshwater mussel Lampsilis rafinesqueana

Abstract Historical periods of rapid climate change and associated direct and indirect impacts such as glaciation and restructuring of drainage systems are important in shaping biodiversity, lineage divergence, and contemporary genetic variation amongst many aquatic taxa. Through an understanding of the impacts of these ancient changes in land‐ and waterscapes on current diversity, practitioners can account for a species' unique evolutionary history when developing conservation strategies. We investigated intraspecific genetic diversity of the critically endangered freshwater mussel, Lampsilis rafinesqueana, endemic to the interior region of the U.S.A. Our study (1) characterises genetic variation within and amongst populations to infer biogeographic history and (2) applies genetic information to potential conservation strategies. We applied restriction‐site associated DNA sequencing and mitochondrial DNA sequencing to investigate genetic diversity within and amongst populations of L. rafinesqueana from across the species' distribution. We then considered this information in the context of historical riverscape processes and applicability to conservation. Variation within rivers was similar, but we found different genetic populations associated with two major ecoregions, the Central Interior Highlands and Osage Plains. The plains population displayed an Ne value approximately 10‐fold lower than the highlands population. Historical demographic modelling suggests the two populations diverged approximately 1.2 million years ago and then both populations underwent a substantial decrease in population size around 19,700 years ago. These two major events are each correlated with known periods of historic rapid climate change. We identified two distinct populations of a federally endangered mussel, L. rafinesqueana. Contemporary genetic diversity of this species was strongly influenced by direct and indirect impacts of rapid historic shifts in climate. The highlands population has undergone a recent expansion, typical of post‐Pleistocene climate change, while also having a much larger Ne value than the plains population. Our results suggest low levels of gene flow amongst the two distinct populations across generations. We recommend that conservation managers for this species take into account relative difference in diversity between populations when developing management strategies. In many species, assisted gene flow amongst genetically unique populations should only be considered in extreme circumstances; however, in L. rafinesqueana, low levels of assisted migration amongst populations may be a valuable tactic to maintain natural levels of genetic variation. Our study shows that biogeographical frameworks can be useful for developing conservation strategies that serve to retain important genomic variation that represents the evolutionary potential of target freshwater species.

Widespread cultural change in declining populations of Amazon parrots.

Species worldwide are experiencing anthropogenic environmental change, and the long-term impacts on animal cultural traditions such as vocal dialects are often unknown. Our prior studies of the yellow-naped amazon (Amazona auropalliata) revealed stable vocal dialects over an 11-year period (1994-2005), with modest shifts in geographic boundaries and acoustic structure of contact calls. Here, we examined whether yellow-naped amazons maintained stable dialects over the subsequent 11-year time span from 2005 to 2016, culminating in 22 years of study. Over this same period, this species suffered a dramatic decrease in population size that prompted two successive uplists in IUCN status, from vulnerable to critically endangered. In this most recent 11-year time span, we found evidence of geographic shifts in call types, manifesting in more bilingual sites and introgression across the formerly distinct North-South acoustic boundary. We also found greater evidence of acoustic drift, in the form of new emerging call types and greater acoustic variation overall. These results suggest cultural traditions such as dialects may change in response to demographic and environmental conditions, with broad implications for threatened species.

Genetic Diversity of the Common Black Carp Strain (Cyprinus carpio var. baisenensis)

The Common Black Carp Strain (Cyprinus carpio var. baisenensis), known for its black skin, is commonly cultured in the integrated rice-agriculture (IRA) system in Guangxi province, China. This study aimed to compare the genetic diversity of three common carp strains/populations (Common Black Carp Strain, Huanghe, and Songpu) using resequencing data. The genome-based method reveals a significant difference (p &lt; 0.05) in identified loci and SNP frequency (p &lt; 1 × 10−6) between the Songpu (Sp) or mirror carp and Huanghe (Hh) new strain. Additionally, the Common Black Carp Strain (Bk) exhibits a higher number of Tajima’s D values, possibly due to its population size and mutations within its entire genome. The average value of population nucleotide diversity (π) for the Bk is 1.706 × 10−4 while the mean number for the Hh and Sp strains is 1.691 × 10−4 Heterozygosity analysis results indicate that the Bk has the highest F coefficient compared to the Sp and Hh hybrids. This suggests that the isolated population of the Bk may have experienced a decrease in population size as a result of environmental disturbances in the IRA system. PCA results further reveal that all individuals of the Bk, except for one, are clustered together, while individuals of the Hh form a separate group. On the other hand, Sp displays a distinct distribution pattern. The comparative study of the genetic diversity of the Bk provides baseline data on its genome makeup. Assessing genetic diversity and genetic structure is critical for fisheries management and the conservation of critically endangered fish species.

Genetic consequences in the southern African endemic seabream Polysteganus undulosus (Sparidae) after eight decades of overfishing

The Critically Endangered seventy-four seabream Polysteganus undulosus, a slow-growing sparid that forms spawning aggregations off South Africa, faced heavy exploitation from 1910 until a fishery moratorium was put in place in 1998. Utilising temporal samples from 1962/1963 (mid-collapse) and 2005/2006 (post-collapse), we assessed genetic diversity at six microsatellite loci. Amplification success for archived samples was low (43%), necessitating a rarefaction approach, revealing a 40% decrease in allelic diversity. Significant genetic differences between recent and archived samples confirmed the impact of overfishing. Simulation studies indicated that missing genotypes did not affect these tests, validating the genetic differences. Using a coalescent-based approach, a 10-fold decrease in effective population size (Ne) was estimated over this 43-year period (Ne = 43.88 to 4.76). Simulations provided corrected Ne of 36.86, accounting for missing genotypes that were responsible for inflated values. Assuming 25% of pristine levels in the 1960s, pristine Ne values ranged from 147 to 176 in 1910, suggesting a 96.8–98.3% genetic decline over 88 years of exploitation. This study emphasises severe genetic consequences of overfishing on P. undulosus diversity and effective population size. The results provide vital genetic baseline data for recovery assessment and conservation efforts, as well as an analytical framework to evaluate the stock decline using partial genotyping data gathered from degraded archived samples.

Centrality to the metapopulation is more important for population genetic diversity than habitat area or fragmentation.

Drift and gene flow affect genetic diversity. Given that the strength of genetic drift increases as population size decreases, management activities have focused on increasing population size through preserving habitats to preserve genetic diversity. Few studies have empirically evaluated the impacts of drift and gene flow on genetic diversity. Kryptolebias marmoratus, henceforth 'rivulus', is a small killifish restricted to fragmented New World mangrove forests with gene flow primarily associated with ocean currents. Rivulus form distinct populations across patches, making them a well-suited system to test the extent to which habitat area, fragmentation and connectivity are associated with genetic diversity. Using over 1000 individuals genotyped at 32 microsatellite loci, high-resolution landcover data and oceanographic simulations with graph theory, we demonstrate that centrality (connectivity) to the metapopulation is more strongly associated with genetic diversity than habitat area or fragmentation. By comparing models with and without centrality standardized by the source population's genetic diversity, our results suggest that metapopulation centrality is critical to genetic diversity regardless of the diversity of adjacent populations. While we find evidence that habitat area and fragmentation are related to genetic diversity, centrality is always a significant predictor with a larger effect than any measure of habitat configuration.

Large shallow lake response to anthropogenic stressors and climate change: Missing macroinvertebrate recovery after oligotrophication (Lake Balaton, East-Central Europe)

East-Central Europe's largest shallow lake, Balaton, experienced strong eutrophication in the 1970–80s, followed by water quality improvement and oligotrophication by 2010 CE. Recently however, repeated cyanobacterial blooms occurred and warned that internal P-recycling can act similarly to external P load, therefore we need a better understanding of past water level (WL) and trophic changes in the lake. In this study we discuss the last 500-yr trophic, WL and habitat changes of the lake using paleoecological (chironomids, pollen) and geochemical (sediment chlorophyll, TOC, TS, TN, C/H ratio, major and trace element) methods. We demonstrate that the most intensive and irreversible change in the macroinvertebrate fauna occurred during the period of economic boom between the First and Second World War (∼1925–1940 CE), when large-scale built-in and leisure use of the lake has intensified. At that time, the Procladius-Microchironomus-Stempellina dominated community transformed to Procladius-Chironomus plumosus-type-Microchironomus community that coincided with land use changes, intensified erosion and water-level regulation in the lake with the maintenance of year-round high WL. This was followed by the impoverishment and population size decrease of the chironomid fauna and Procladius dominance since 1940 CE, without any recovery after 1994 CE despite the ongoing oligotrophication. Accelerated rate of change and turnover of the fauna was connected to an increase in the benthivorous fish biomass and eutrophication. The basin lost almost completely its once characteristic Stempellina species between 1927 and 1940 CE due to trophic level increase and seasonal anoxia in the Szemes Basin. Reference conditions for ecosystem improvement were assigned to 1740–1900 CE. We conclude that in spite of the ongoing oligotrophication, the re-establishment of the Procladius-Microchironomus-Stempellina assemblage is hampered, and requires fish population regulation.

A sea of change: Tracing parasitic dynamics through the past millennia in the northern Adriatic, Italy

Abstract Our study uses data from Holocene core samples and modern death assemblages to understand how human-induced environmental change in the northern Adriatic Sea (Italy) may have affected parasite-host dynamics in the economically important bivalve Chamelea gallina. Thirty-one radiocarbon dates confirm temporal distinctness between the periods before and after the onset of significant human influence and confirm that trematode prevalence has decreased by an order of magnitude over the past ~2 k.y. The median number of parasite-induced pits per bivalve host and parasite aggregation has also decreased significantly, signaling a substantial decrease in the effective population size of digenean trematodes. Gaussian finite mixture modeling of pit size does not support the hypothesis of parasite extinction. Combined, these results indicate the (potentially ongoing) collapse of parasite-host interactions in C. gallina in concert with human influence on the Adriatic and its transition to an “urban sea.”

Genetic variation of English yew (Taxus baccata L.) in the Bavarian Forest National Park, Germany

AbstractTaxus baccata L. is a highly valuable species with wide distribution but scattered and locally rare occurrence. Human intervention, including forest management practices and fragmentation, can significantly impact the species’ genetic diversity, structure, and dynamics. In this study, we investigated these factors within T. baccata populations in the Bavarian Forest National Park (NP) in Germany and their implications for conservation. We used 13 EST-SSRs to assess the genetic diversity and structure of the population. Our analysis revealed a scarcity of small-diameter trees, indicating limited natural regeneration over time. However, conservation efforts, like selectively removing competitor species and using protective fencing, have improved growth conditions and promoted seedling emergence. The NP’s natural zone has no active management, which is confined to the development and management zones. Genetic diversity assessments revealed high genetic diversity (He: 0.612 and 0.614 for seedlings and adults, respectively) compared to other studies in Taxus baccata, dispelling concerns of significant inbreeding and showcasing a stable genetic structure. However, significant spatial clustering of related individuals (family structures) in both cohorts and low effective population size in the progeny hints at restricted gene flow, necessitating conservation efforts prioritizing safeguarding and promoting natural regeneration in development and management zones. Limited natural regeneration and the recent decrease in effective population size in the NP populations indicate habitat fragmentation and human interventions. Effective population size estimates emphasize the need for diverse conservation strategies. Conservation efforts should prioritize protecting natural regeneration and enhancing gene flow by actively promoting European yew, e.g., by shelterwood cutting, to ensure the long-term viability of T. baccata in the region outside the NP.

Efficient purging of deleterious mutations contributes to the survival of a rare conifer.

Cupressaceae is a conifer family rich in plants of horticultural importance, including Cupressus, Chamaecyparis, Juniperus, and Thuja, yet genomic surveys are lacking for this family. Cupressus gigantea, one of the many rare conifers that are threatened by climate change and anthropogenic habitat fragmentation, plays an ever-increasing role in ecotourism in Tibet. To infer how past climate change has shaped the population evolution of this species, we generated a de novo chromosome-scale genome (10.92Gb) and compared the species' population history and genetic load with that of a widespread close relative, C. duclouxiana. Our demographic analyses, based on 83 re-sequenced individuals from multiple populations of the two species, revealed a sharp decline of population sizes during the first part of the Quaternary. However, populations of C. duclouxiana then started to recover, while C. gigantea populations continued to decrease until recently. The total genomic diversity of C. gigantea is smaller than that of C. duclouxiana, but contrary to expectations, C. gigantea has fewer highly and mildly deleterious mutations than C. duclouxiana, and simulations and statistical tests support purifying selection during prolonged inbreeding as the explanation. Our results highlight the evolutionary consequences of decreased population size on the genetic burden of a long-lived endangered conifer with large genome size and suggest that genetic purging deserves more attention in conservation management.

Modeling viral evolution: A novel SIRSVIDE framework with application to SARS-CoV-2 dynamics

Understanding evolutionary trends in emerging viruses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is crucial for effective public health management and response. Nonetheless, extensive debates have arisen concerning viral evolutionary trends, particularly the interplay between transmissibility, pathogenicity, and immune escape. In this context, we have developed a novel computational model named SIRSVIDE (Susceptible-Infected-Recovered-Susceptible-Variation-Immune Decay-Immune Escape) to simulate the transmission and evolutionary dynamics of viral populations. Our simulation results indicate that under conditions of high mutation rates, elevated transmission rates, and larger susceptible host populations, viral populations exhibit prolonged increases in transmissibility and immune escape, accompanied by reductions in pathogenicity and noticeable short-term fluctuations. However, when the total susceptible population size and mutation rate decrease, substantial uncertainty in the evolutionary trends of viral populations becomes apparent. In summary, the SIRSVIDE model establishes a comprehensive framework for generating both short- and long-term viral epidemiological and evolutionary dynamics. The simulation outcomes align with existing evidence indicating that SARS-CoV-2 is undergoing selection for heightened transmissibility, decreased pathogenicity, and enhanced immune escape. Furthermore, the model sheds light on the possible evolutionary dynamics of other viruses.

Phylogeography of the freshwater crab Potamon persicum (Decapoda: Potamidae): an ancestral ring species?

The Zagros Mountains, characterized by complex topography and three large drainage systems, harbor the endemic freshwater crab Potamon persicum in Iran. Our study delves into the evolutionary history of P. persicum, utilizing two mitochondrial and one nuclear marker. We collected 214 specimens from 24 localities, identifying 21 haplotypes grouped into two major evolutionary lineages. Substantial differentiation exists between drainage systems and lineages. Historical demographic analysis revealed a significant decrease in population size during the late Holocene, accompanied by a recent population bottleneck. Species distribution modeling has revealed eastward shifts in suitable habitats between the last glacial maximum and the present day. Following the last glacial maximum, habitat fragmentation occurred, resulting in the establishment of small populations. These smaller populations are more vulnerable to climatic and geological events, thereby limiting gene flow and accelerating genetic differentiation within species. Historical biogeographic analysis traced the origin of P. persicum to the western Zagros Mountains, with major genetic divergence occurring during the Pleistocene. Our genetic analyses suggest that P. persicum may have shown a genetic pattern similar to a classical ring species before the Pleistocene. The Namak Lake sub-basin could have served as a contact zone where populations did not interbreed but were connected through gene flow in a geographic ring. Currently, genetic separation is evident between basins, indicating that P. persicum in the Zagros Mountains is not a contemporary ring species. Also, our biogeographical analysis estimated that range evolution may have been driven initially by dispersal, and only during the late Pleistocene by vicariance.

Does urbanisation lead to parallel demographic shifts across the world in a cosmopolitan plant?

Urbanisation is occurring globally, leading to dramatic environmental changes that are altering the ecology and evolution of species. In particular, the expansion of human infrastructure and the loss and fragmentation of natural habitats in cities is predicted to increase genetic drift and reduce gene flow by reducing the size and connectivity of populations. Alternatively, the 'urban facilitation model' suggests that some species will have greater gene flow into and within cities leading to higher diversity and lower differentiation in urban populations. These alternative hypotheses have not been contrasted across multiple cities. Here, we used the genomic data from the GLobal Urban Evolution project (GLUE), to study the effects of urbanisation on non-adaptive evolutionary processes of white clover (Trifolium repens) at a global scale. We found that white clover populations presented high genetic diversity and no evidence of reduced Ne linked to urbanisation. On the contrary, we found that urban populations were less likely to experience a recent decrease in effective population size than rural ones. In addition, we found little genetic structure among populations both globally and between urban and rural populations, which showed extensive gene flow between habitats. Interestingly, white clover displayed overall higher gene flow within urban areas than within rural habitats. Our study provides the largest comprehensive test of the demographic effects of urbanisation. Our results contrast with the common perception that heavily altered and fragmented urban environments will reduce the effective population size and genetic diversity of populations and contribute to their isolation.

Marine fishes experiencing high-velocity range shifts may not be climate change winners.

Climate change is driving the global redistribution of species. A common assumption is that rapid range shifts occur in tandem with overall stable or positive abundance trends throughout the range and thus these species may be considered as climate change 'winners'. However, although establishing the link between range shift velocities and population trends is crucial for predicting climate change impacts it has not been empirically tested. Using 2,572 estimates of changes in marine fish abundance spread across the world's oceans, we show that poleward range shifts are not necessarily associated with positive population trends. Species experiencing high-velocity range shifts seem to experience local population declines irrespective of the position throughout the species range. High range shift velocities of 17 km yr-1 are associated with a 50% decrease in population sizes over a period of 10 yr, which is dramatic compared to the overall stable population trends in non-shifting species. This pattern, however, mostly occurs in populations located in the poleward, colder, portion of the species range. The lack of a positive association between poleward range shift velocities and population trends at the coldest portion of the range contrasts with the view that rapid range shifts safeguard against local population declines. Instead, our work suggests that marine fishes experiencing rapid range shifts could be more vulnerable to climatic change and therefore should be carefully assessed for conservation status.

Scenarios of the Near Future: Sustainable Development, Retreat or Collapse and Regeneration?

The elementary “map of the near future” could consist of three basic scenarios: sustainable development; sustainable retreat; or collapse and regeneration. Sustainable development remains the most serious attempt at finding an answer to the question of how to allow all people and nations to develop and improve their quality of life, while preserving functional ecosystems and a healthy environment for humankind. James Lovelock was the first to articulate the idea that it is too late for sustainable development and that we should strive for sustainable retreat. For Lovelock, the deadliest issue is the ongoing climate change, as it is irreversible and only can be mitigated. Sustainable retreat is hard to enforce politically and difficult to absorb mentally. Collapse of a civilization is a decrease in population size or political, economic, and social complexity over a large area for a long time. The collapse of a society does not usually come in the form of a sudden and apocalyptic downfall. Whether a society collapses or not depends on the society´s response to its problems and its capacity to solve them. A collapse is usually followed by rebirth and regeneration. This is a pattern in nature. Human society has followed a similar trend. Regardless how big a crisis is, it always presents an opportunity for catharsis and hope for a new beginning. However, there is no guarantee of the results.

Bigger is better: age class‐specific survival rates in long‐lived turtles increase with size

AbstractVital rates for small, non‐breeding individuals are important components of population dynamics for many species, but often individuals of these sizes are difficult to locate, capture, and track. As such, biologists frequently lack reliable estimates of juvenile survival because sample sizes and recapture rates for this life stage are low. Long‐lived animals often take many years to reach sexual maturity and spend much of this time in the smaller size classes, making them sensitive to changes in survival rates. We estimated the survival rates of all size classes for the northern map turtle (Graptemys geographica) using a mark‐recapture dataset with &gt;3,500 captures from 2019–2021 and 210 nests from 2018–2021. As turtle size increased, annual survival probability increased regardless of sex. Estimated annual survival probability for turtles &gt;18 cm long (i.e., adult females &gt;15 years) was about 0.95, over 4 times higher than turtles that were 3 cm long (i.e., hatchlings &lt;1 year; 0.22 annual survival probability). Although we did not observe a difference in survival probability between sexes of any size class, adult females are nearly twice the size of adult males, leading to an increased annual survival probability for females of 0.95, compared to 0.80 for males. Changes in adult survival had the greatest influence on population estimates over time, with temporary decreases, such as those due to poaching or an environmental disaster, potentially leading to unrecoverable decreases in the overall population size. Our study provides detailed survival rates for all size classes in a long‐lived turtle, which are necessary to assess population stability and can be used to determine the most effective conservation or management practices.

The population development of small trees and shrubs after 100 years of free succession of a wooded meadow in southern Sweden

Wooded meadows are characterised by traditional-historic human use. Deliberate selection of species, pollarding and haymaking has created a complex and biodiverse habitat where small trees and shrubs were prevalent. This study set out to document what happens to such trees and shrubs during succession to forest, the normal fate when wooded meadows are abandoned but also when other open to semi-open patches revert to forest. The study was conducted at a site in southern Sweden where traditional management was abandoned by 1923 when the area was protected for research and allowed to follow natural succession. The current study is a follow-up of a 1937-inventory of small trees and shrubs. The results show a decrease in both population size and canopy cover in the selected species during the past 86 years. Hence, we can expect a loss of these species when wooded meadow are abandoned and left to developed into forests. On the other hand, several tree and shrub specimens endured for a century, pointing to the slow changes involved as well as the potential for restoration.

IMPLEMENTASI GEOGRAPHICALLY WEIGHTED LOGISTIC REGRESSION PADA LAJU PERTUMBUHAN PENDUDUK DI BOJONEGORO

Population Growth Rate is the rate at which influencing factors increase and decrease population size. The development of large populations in regional governments causes uncontrolled population growth rates. The population growth rate in Bojonegoro Regency from 2019 to 2020 experienced a significant increase of 0.96%. The increase in population has an impact on the emergence of various problems in the economic and social fields. This problem requires effective and comprehensive spatial modeling, namely Geographically Weighted Logistic Regression (GWLR) with Fixed Gaussian and Adaptive Gaussian weighting. GWLR modeling aims to determine the implementation of knowledge and insight into the factors that influence the rate of population growth in each area of ​​Bojonegoro District. based on the results of GWLR modeling with the Akaike Index Criteria (AIC) on the Fixed Gaussian kernel function of 33.91. This value identifies that the population growth rate modeling in each sub-district has different values. This difference can be seen from 6 sub-districts which are significantly influenced by the number of births and 5 sub-districts are significantly influenced by the number of couples of childbearing age who participate in family planning. The results of modeling predictions (GWLR) in Bojonegoro Regency show that 11 sub-districts have low growth rate categories while 17 sub-districts have high population growth rate values