Fragmentation Of Natural Habitats Research Articles

Public attitudes to urban wild deer (Cervus nippon) and management policies: A case study of Kyoto City, Japan

The expansion of urban areas has resulted in the fragmentation and reduction of natural habitats. This leads to a fundamental reconfiguration of interactions between humans and wildlife, with profound ecological, social, and policy implications. However there is a research gap in understanding public perceptions of urban wildlife and their management. This study pursues three objectives: (1) to explore the primary types of conflicts between the public and urban wildlife, focusing on Sika deer (Cervus nippon) as an example; (2) to examine public attitudes towards urban deer; and (3) to investigate differences in public acceptance of hunting and fencing management policies. A questionnaire survey was conducted in the urban area of Kyoto City, Japan in September 2022 (n = 759). The survey addressed issues related to deer behavior in the city, public perceptions of urban deer, and feedback on management policies We employed statistical descriptive analysis to study the main ways in which people interact with urban deer. Subsequently, we examined the urban deer image from the public perspective and public perceptions of urban deer. Additionally, mining analysis was conducted on open-ended responses, and public demands were explored in conjunction with feedback on current management schemes in Kyoto City The results indicate that the main type of human-urban deer conflict has an impact on damaging urban vegetation. Public attitudes towards urban deer and other wildlife (besides deer) show significant differences but tend towards negative attitudes. We found a positive inclination towards the efficacy of fencing as a viable solution concurrently revealing a low-approving sentiment regarding hunting policies. These findings bear implications for the development and enhancement of sustainable management strategies aimed at mitigating the complex challenges posed by the swift urbanisation and evolution of urban ecosystems.

Pollinator-mediated connectivity in fragmented urban green spaces—tracking pollen grain movements in the city center

Cities are expanding rapidly and emerging as complex ecosystems. This expansion of urbanized areas has resulted in the alteration and fragmentation of several natural habitats. Recent studies have shown that cities support a significant level of biodiversity. This unexpected role of cities holds promise for advancing knowledge of urban ecosystems and promoting their conservation. In particular, the connectivity of plant populations through pollen transfer is crucial for the long-term persistence of insect-pollinated plant species. In this study, we tracked pollen movement areas in four isolated patches of urban greenery in urbanized area using quantum dots. We studied Fritillaria imperialis (spring) and Hemerocallis sp. (mid-summer). Our research revealed frequent pollen transfer between small, isolated flowering patches, even when these locations were not connected by green corridors. Common elements found in urban ecosystems, such as streets, trails, and pavements, do not stop the dispersion of pollen grains. Moreover, the migration pathways of pollen grains vary for each species according to different factors. For F. imperialis, we identified the proportion of green areas in proximity to the study location as a key factor in shaping pollen transfer. For Hemerocallis, we discovered that the proportion of green areas, the distance between study sites, and the frequency of pollinator visits are influential factors. Our study demonstrates that small isolated plant populations exchange pollen due to pollinator movement, indicating that these small populations may serve as stepping stones for pollinators among larger populations.

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.

How do different processes of habitat fragmentation affect habitat quality? – Evidence from China

Large-scale loss and fragmentation of natural habitats is one of the critical factors in the global decline of biodiversity. Habitat quality is the foundation for supporting biodiversity, so exploring the mechanisms by which habitat fragmentation affects habitat quality is important for biodiversity protection. However, little is known about the specific forms that various processes of habitat fragmentation affect habitat quality. Taking China as an example, the three processes of habitat fragmentation (the decrease in habitat area, the increase in habitat isolation, and the increase in habitat edge) and variations in habitat quality were quantitatively assessed from 2000 to 2020. On this basis, Pearson coefficients, Generalized Additive Model (GAM) and Geographical detector were employed to examine the linear\ on-linear\\combined impacts of habitat fragmentation different processes on habitat quality. The results indicated that there was a clear trend of habitat fragmentation and degradation of habitat quality in 2000–2020. 56.94%, 42.33%, and 50.89% of the area experienced the decrease in habitat area, the increase in habitat isolation, and the increase in habitat edge, respectively, and 63.12% experienced degradation of habitat quality. All three of these habitat fragmentation processes result in a downward trend in habitat quality. However, the specific form of impacts of habitat fragmentation different processes on habitat quality showed non-linear characteristics. The decrease in habitat area and the increase in habitat isolation consistently had a significant negative influence on habitat quality, albeit with varying strengths at different segments. While the increase in habitat edge causes an overall decrease in habitat quality, the two have a more complex non-linear relationship, with response curves varied between positive and negative correlations. In addition, negative impacts on habitat quality are exacerbated when multiple habitat fragmentation processes occur simultaneously. These findings reveal the complex impacts of different habitat fragmentation processes on habitat quality and inform the development of more rational landscape planning and biodiversity conservation measures in China.

Agricultural landscape composition alters ant communities in maize fields more than plant diversity enrichment

Abstract. Pasaribu DN, Rizali A, Tarno H, Priawandiputra W, Johannis M, Buchori D. 2024. Agricultural landscape composition alters ant communities in maize fields more than plant diversity enrichment. Biodiversitas 25: 205-213. Fragmented natural habitats in human-modified landscapes play a crucial role in conserving biodiversity. Ants, as keystone species, are integral to terrestrial ecosystems, making it essential to comprehend the factors influencing their survival. This study investigates the impact of agricultural landscape composition and plant diversity enrichment (flowering plants) management on shaping ant communities in maize (Zea mays L.) fields. The research occurred in maize fields surrounded by other crops, semi-natural habitats, and housing areas in Malang District, East Java, Indonesia. The four agricultural areas were divided into control and treatment plots, considering landscape composition parameters, particularly Class Area (CA) and the Number of Patches (NP), measured within a 500 m radius. The landscape around the maize fields was characterized by manually digitizing land use. Six types of plant diversity enrichment were employed in this study: wild cosmos (Cosmos caudatus), white buttercup (Turnera subulata), sunflower (Helianthus annuus), long bean (Vigna unguiculata), ornamental bean (Arachis pintoi), and coral vine (Antigonon leptopus). The study was divided into the dry season (April-July 2022) and the wet season (September-December 2022). Ant sampling was conducted using pitfall traps and, based on generalized linear models, revealed that plant diversity enrichment management did not affect species richness, abundance, or composition of ants. Landscape composition positively influenced ant species richness but negatively impacted species composition, particularly the number of semi-natural habitat patches. Maize crop age also positively influenced ant species richness but negatively affected beta diversity. Wet season was also found to have a negative effect on beta diversity. In conclusion, the proportion of semi-natural habitats in agricultural landscapes and crop age contribute significantly to species richness and species composition of ants.

Symbiont plasticity as a driver of plant success.

We discuss which plant species are likely to become winners, that is achieve the highest global abundance, in changing landscapes, and whether plant-associated microbes play a determining role. Reduction and fragmentation of natural habitats in historic landscapes have led to the emergence of patchy, hybrid landscapes, and novel landscapes where anthropogenic ecosystems prevail. In patchy landscapes, species with broad niches are favoured. Plasticity in the degree of association with symbiotic microbes may contribute to broader plant niches and optimization of symbiosis costs and benefits, by downregulating symbiosis when it is unnecessary and upregulating it when it is beneficial. Plasticity can also be expressed as the switch from one type of mutualism to another, for example from nutritive to defensive mutualism with increasing soil fertility and the associated increase in parasite load. Upon dispersal, wide mutualistic partner receptivity is another facet of symbiont plasticity that becomes beneficial, because plants are not limited by the availability of specialist partners when arriving at new locations. Thus, under conditions of global change, symbiont plasticity allows plants to optimize the activity of mutualistic relationships, potentially allowing them to become winners by maximizing geographic occupancy and local abundance.

Chiropterofauna (Mammalia: Chiroptera) from the Altamiro de Moura Pacheco State Park, Goiás, Brazil

The Brazilian Cerrado is undergoing important changes. It is estimated that 70% of its natural area has converted to human use. The loss and fragmentation of natural habitats is considered the main cause of species loss in ecosystems. However, the lack of knowledge of biodiversity makes it difficult to design effective conservation measures. This article presents a list and an estimate of the richness of bats in the Parque Estadual Altamiro de Moura Pacheco (PEAMP) in Goiás. All collected bats belong to the Phyllostomidae family, with Carollia perspicillata (67%) and Artibeus planirostris (18%) representing 86% of the captured individuals.

Trends of Human-Wildlife Conflicting in Kali Tiger Reserve Forest, Karnataka, South India

Human-wildlife conflict (HWC) is a growing concern, impacting both conservation efforts and livelihoods. This study was conducted to analyse trends in wildlife conflicts involving agriculture, cattle, and human injuries from 2015-16 to 2022-23 with a focus on the Kali Tiger Reserve in Karnataka, India. The compound annual growth rate (CAGR) method was used to assess the data, revealing critical insights. Agriculture-wildlife conflict showed an overall upward trend with a CAGR of 3.16 per cent. Notably, there was a significant increase in 2016-17, followed by fluctuations in subsequent years. This conflict arises due to natural habitat fragmentation and deterioration resulting animals encroaching on agricultural fields. Cattle-wildlife conflict exhibited a CAGR of 8.20 per cent, indicating a gradual increase with fluctuating cases from year to year. Tigers and leopards pose a threat to farmers who graze cattle near the forest reserves. Innovative solutions are required to balance the synergy of agriculture production and wildlife management policy. Human injuries due to wildlife displayed fluctuations, with a slight overall decrease (CAGR -0.47%) in the number of cases and an increase of 2.66 per cent in compensation. These incidents occur when people venture into forests for various reasons. Proper regulations and permissions are necessary to minimize such encounters. Overall compensation payments showed a CAGR of 5.83 per cent, reflecting fluctuating growth rates and significant changes in 2022-23. The forest and wildlife conservation sectors determine compensation based on specific factors for crop loss, cattle deaths, and human injuries. However, conflicts related to human injuries have shown a declining trend. The study suggests relocating rehabilitation efforts away from forest buffer zones and introducing off farm activities for affected communities to reduce their dependence on the forest.

Impacts of livestock grazing on blue‐eared pheasants (Crossoptilon auritum) survival in subalpine forests of Southwest China

AbstractThe degradation and fragmentation of natural habitats, driven largely by anthropogenic activities such as grazing, represent growing concerns in environmental conservation. We examined the impact of grazing activities on the survival of the blue‐eared pheasant Crossoptilon auritum, a ground‐nesting bird endemic to subalpine forests. Using camera‐trapping and artificial nest experiments, we compared two sites in Sichuan, China: Wanglang (high grazing intensity) and Jiuzhaigou (no grazing) national nature reserves. The study, conducted from 2017 to 2021, evaluated habitat suitability changes for these pheasants and examined the impact of grazing on nesting success by conducting a nest predation experiment. The results of our study showed that (1) since the significant increase of free‐ranging livestock post‐2014, the area of most suitable and moderately suitable habitats for blue‐eared pheasants in Wanglang decreased by 14.28% (net loss 15.12 km2); (2) predominant natural predators of the pheasant, such as yellow‐throated martens (Martes flavigula) and leopard cats (Prionailurus bengalensis), were mostly observed to be spatially distant from livestock; (3) the pheasant's nesting failure rate was 2.18 times higher in Wanglang than in Jiuzhaigou; (4) high‐intensity livestock disturbance correlated with decreased food resources for pheasants, yet resulted in an increased abundance of Coleopteran insects. These results illustrate a complex dynamic: Although forest pheasants, such as the blue‐eared pheasant, may initially benefit from the presence of livestock through increased predator refuge and access to specific food resources, they ultimately face greater risks. These include a significant increase in nest failure rates and remarkable habitat loss and degradation. In light of these results, we advocate for strict control and management of grazing activities inside reserves. Additionally, we recommend the implementation of a systematic monitoring program that focuses on the population dynamics and habitat use of endangered pheasants in Southwest China.

Population size is not a reliable indicator of seed germination

AbstractSmall isolated plant populations are one of the consequences of fragmentation of natural habitats by humans. We asked what effect does the creation of smaller populations from larger ones has on the plant fitness-related trait seed germination. Using information on 119 species (142 species entries) in 50 families, we found that seeds in only 35.2% of the species entries from larger populations germinated to higher percentages than those from smaller populations. In the other entries, seeds from large and small populations germinated equally well (57.7% of total entries) or seeds from small populations germinated better (7.0% of total entries) than those from large populations. These results indicate that population size is not a reliable predictor of seed germinability. Furthermore, there was little relationship between seed germination and either seed mass, genetic diversity or degree of population isolation, or between population size and genetic diversity.

Whole-genome resequencing confirms the genetic effects of dams on an endangered fish Hemibagrus guttatus (Siluriformes: Bagridae): A case study in a tributary of the Pearl River

Dam construction in riverine ecosystems has fragmented natural aquatic habitats and has altered environmental conditions. As a result, damming has been demonstrated to threaten aquatic biodiversity by reducing species distribution ranges and hindering gene exchange, leading to the inability to adapt to environmental changes. Knowledge of the contemporary genetic diversity and genetic structure of fish populations that are separated by dams is vital to developing effective conservation strategies, particularly for endangered fish species. We chose the Lianjiang River, a tributary of the Pearl River, as a case study to assess the effects of dams on the genetic diversity and genetic structure of an endangered fish species, Hemibagrus guttatus, using whole-genome resequencing data from 63 fish samples. The results indicated low levels of genetic diversity, high levels of inbreeding and decreasing trend of effective population size in fragmented H. guttatus populations. In addition, there were significant genetic structure and genetic differentiation among populations, suggesting that the dams might have affected H. guttatus populations. Our findings may benefit management and conservation practices for this endangered species that is currently suffering from the effects of dam construction.

No impact of habitat fragmentation on condition and dispersal ability in the highly mobile butterfly Pieris rapae

AbstractThe loss and fragmentation of natural habitats due to agricultural intensification have a strong negative impact on farmland biodiversity. The concomitant isolation of essential resources may exert selection pressures toward increased dispersal performance in flying insects, possibly resulting in differences in flight morphology and dispersal propensity across landscapes. Here, we compared condition, flight morphology, dispersal capacity, and propensity of the common butterfly Pieris rapae among four pairs of highly fragmented “modern” and less fragmented “traditional” agricultural landscapes. We did not find differences between landscape types, but between locations and sexes. These results are not entirely unexpected, as P. rapae is a highly mobile generalist species, able to exploit temporarily available resources such as rapeseed in modern agricultural landscapes. In addition, our negative results may suggest a lack of time for evolutionary change such that differences may appear in the future. However, more specialized species with low dispersal ability may show clearer patterns and may well suffer from habitat fragmentation, and investigating such interrelation is an important task for future research.

Agriculture in the cerrado: a sleeping giant rose up

Cerrado is a savanna biome, the second in extension among Brazilian ecosystems. The soils of the Cerrado are among the oldest on Earth. Weathering effects resulted in impoverished, acid soils in the Cerrado. Until the inauguration of Brasília (the capital of Brazil) in central Brazil, Cerrado was regarded as useless for agricultural exploitation. Research and implementation of techniques of soil fertilization, plant and animal genetics, breeding, and farming technology turned the Cerrado the main Brazilian area for food production. Notable gains in overall production and productivity of several crops were obtained. Over four decades, grain production in Brazil increased 6-fold, whereas the cultivated area increased 1.6-fold. Brazil became the third world’s food producer and the second top exporter of food products. On the other hand, much of the original extension of the Cerrado domain was replaced by farming fields. In consequence, Cerrado is presently the most threatened Brazilian biome, chiefly due to losses and fragmentation of natural habitats. A balance between farming and environmental protection of the Cerrado is needed, aiming a sustainable food production, by means of a harmonic convivence of farming and environment preservation.

Quantifying the landscape changes within and outside the Dachigam National Park, Kashmir Himalaya, India using observations and models.

Protected areas are the cornerstone of biodiversity and serve as a haven for biodiversity conservation. However, due to immense anthropic pressures and ongoing changes in climate, the protected reserves are under immense threat. Human interference through land system changes is a major precusor of fragmentation of landscapes resulting in the decline of Himalayan biodiversity. In this context, this research assessed land use land cover changes (LULCCs) and fragmentation within and outside the Dachigam National Park (DNP) using remote sensing data, GIS-based models and ground truth over the past 55 years (1965-2020). Landscape Fragmentation Tool (LFT) helped to compute edge effect, patchiness, perforation and core areas. The Land Change Modeller (LCM) of IDRISI TerrSet was used for simulating the future LULC for the years 2030, 2050, 2700 and 2100. The analysis of LULCCs showed that built-up and aquatic vegetation expanded by 326% and 174%, respectively in the vicinity of the DNP. The area under agriculture, scrub and pasture decreased primarily due to intensified land use activities. Within the DNP, the area under forest cover declined by 7%. A substantial decrease was observed in the core zone both within (39%) and outside (30%) the DNP indicative of fragmentation of natural habitats. LCM analysis projected 10% increase in the built-up extents besides forests, shrublands and pastures. This knowledge generated in this study shall form an important baseline for understanding and characterising the human-wildlife relationship, initiating long-term ecological research (LTER) on naturally vegetated and aquatic ecosystems (primarily Dal Lake) of the region.

Breeding records, urban habitat, and threats to the masked palm civet in Taiwan

AbstractAn increasing number of mammalian species worldwide have adapted to urban environments following the alteration and fragmentation of natural habitats. In recent years, the masked palm civet (Paguma larvata) has increased in several highly populated cities in Taiwan. Twelve‐years (2010–2021) of civet records in Taichung (the largest city in central Taiwan) from the rescue center of Taichung Wildlife Conservation Group report the population of civets has grown steadily since 2017, with the number of records in 2020 (n = 58) and 2021 (n = 55) approximately 5 times of that in 2010–2014 (mean ± SD = 5.0 ± 2.6). Our objective was to use the records from the rescue center to evaluate the potential sexual dimorphism of urban civets, explore temporal variation of civet activity and age structure, identify major threats to civets inhabiting urban areas, and investigate the environmental characteristics surrounding civet nesting sites in urban environments. The civet breeding season lasts from spring to autumn, with primary mating season in spring. The main cause of mortality in adults was dog attack followed by car accident, while the main rescue reason for young civets was because they were considered orphans following human interferences. Many civets in urban areas inhabit locations where >90% of the land cover is covered by buildings and man‐made structures, and even nest inside buildings. Our results demonstrated the need for new civet conservation and management policies to minimize dog attacks on civets to enhance co‐existence between wildlife and humans.

Preserving large tracts of natural grassland promotes mammal species richness and occurrence in afforested areas

The global loss of biodiversity paired with the shortcomings of protected areas highlights the need to improve the conservation potential of human-modified lands. Although often referred to as “ecological deserts”, large spatial scales and long rotation periods make tree plantations a relatively stable and permeable environment that could provide an important link between fragmented natural habitats. Different intensities of afforestation within the same geographic grassland region provide an opportunity to test how transformation by commercial plantations affects local biodiversity. We conducted camera trap surveys at two sites characterised by different degrees of afforestation. We demonstrate a higher mammalian diversity and a higher probability of habitat use in less transformed areas, suggesting that preserving large tracts of native vegetation is vital when offsetting biodiversity loss from timber plantations, especially regarding grassland-specialist species. Community-level habitat use increased in more rugged areas, while in the highly transformed site, habitat use increased closer to indigenous patches and roads. Our research highlights the importance of maintaining comprehensive networks of protected units as part of a broader landscape management approach and identifies a major challenge for the forestry industry moving forward, with plantation stands being dominated by species that threaten the long-term sustainability of the crop itself.

Supplementation of seasonal natural resources with year‐round anthropogenic resources by coyotes in natural fragments within a high‐density urban area

Coyotes Canis latrans in urban landscapes provide important food web functions and ecological services but can also trigger human‐wildlife conflict when their diet includes anthropogenic resources or domestic pets. As adaptable omnivores, coyotes adjust their diet to their environment, routinely switching among food items to accommodate spatial and seasonal differences in availability. To evaluate the coyote's potential impacts within the food web of urban Long Beach, California where human‐wildlife conflict involving coyotes may occur, we analyzed 115 scat samples collected once every two weeks from four open space fragments inside the urban matrix. We hypothesized that differences in scat composition would correlate with seasonal and site differences, with greater use of anthropogenic resources during the dry season supplementing lower prey availability, and with greater consumption of wild mammal prey during the wet season when fruiting plants are less abundant. We found coyote diet was predominately composed of natural prey and vegetation year‐round, with seasonal variation. Mammals made up more of coyote diet in the wet season than the dry, while invertebrates and vegetation were more prevalent in dry season scats. Coyotes relied on rabbits as their main prey year‐round across all sites. Domestic cats Felis catus were the third most common individual prey species found in coyote scats, occurring in 14% of scat samples in both seasons. Coyotes also supplemented seasonally available natural food sources with anthropogenic resources, which occurred in 13% of coyote scats overall with no significant seasonal variation. While rabbits appeared in scat from all sites, the occurrence of invertebrates, small mammals, and vegetation in scats varied between sites. While there is a potential for human‐wildlife conflict in coyote's consumption of feral or domestic cats, coyotes may also be providing an ecological service by reducing cats in natural habitat fragments.

Strong decreases in genetic diversity despite high gene flow for a solitary bee

Many organisms live in landscapes that include fragments of natural habitat interspersed with agricultural or urban areas. In such areas, dispersal across human-dominated landscapes may be important for the maintenance of genetic diversity within habitat fragments. Understanding the extent to which dispersal occurs across fragmented habitat and how genetic diversity changes over time is particularly important for bee populations. Population sizes of many bee species are declining, which can have profound negative impacts on both agricultural pollination and the fitness of wild plants. We quantified dispersal across 100 km of mixed landscapes in southern Costa Rica for the solitary bee species Euglossa championi, and we quantified changes in genetic diversity over an eleven-year period. Our SNP-based analysis revealed high dispersal across the geographic area and no evidence that deforestation restricted dispersal. However, we found strong decreases in genetic diversity over time. Expected heterozygosity decreased by 28% over eleven years, regardless of the amount of forest that surrounded sites. Our results suggest that while high dispersal over deforested landscapes may render E. championi less susceptible to land use change than species that show restricted dispersal, the strong decrease in genetic diversity within sites over time suggests this species may warrant conservation monitoring.

Habitat quality assessment based on InVEST model - Zhengzhou, China

Human activities and global urbanisation have affected the integrity and continuity of ecological land, and resulted in the fragmentation of natural habitats and worldwide ecological security issues. Some ecological functions of landscape patches have been degraded or even lost. We need to study the impact of land use changes on natural habitats that are caused by urbanisation. As the research area, we selected Zhengzhou, a city in central China that has undergone rapid urbanisation in the early 21st century. By using the InVEST-habitat quality model and ArcGIS geographical analysis, we evaluated changes in land use and habitat quality in Zhengzhou from 2000 to 2020. The results show that: The area of construction land increased sharply by 806.76km2 from 2000 to 2010, while during 2010-2020 the growth rate slowed to 33km2 per year, and most of it was converted from arable land. The area of forest and grassland was also greatly reduced in 2000-2010, but did not change significantly in 2010-2020. This indicates that urban expansion gradually shifted from the acceleration of 2000-2010 to a period of stability in 2010-2020, and construction land has taken over a large amount of arable land. Habitat quality was higher in the mountain forests to the west and the south, while the low habitat quality areas in the eastern plain gradually expanded with the development of urban construction. The Yellow River, the most important river in China, was also negatively affected by urbanisation in the north of Zhengzhou, but its habitat quality gradually improved during 2010-2020. In the central urban area, habitat quality was improved in some places due to the creation of green spaces and artificial lakes in recent years, and also through with the improved maintenance of green spaces. However, it is worth continuing to explore whether artificial lakes and large-scale green spaces are the optimal solutions to improve habitat quality. In the future, we will be able to seek the best cost-effective ecological protection methods in terms of economic investment and ecological benefits.

Conservation Status and Effectiveness of the National and International Policies for the Protection and Conservation of Sturgeons in the Danube River and Black Sea Basin

Rivers and their watersheds have been subject to various changes, including biodiversity, caused by anthropogenic activities. The Danube River and Black Sea basin overlap the geographic range of six species of anadromous fish belonging to the family Acipenseridae. Nowadays, they are endangered or at risk of extinction in the wild due to fragmentation and destruction of natural habitats, blocking their migration to spawning grounds, water pollution, and poaching. This paper presents a review of the historical and current distribution and evolution of the sturgeon populations of sturgeon species in the Danube River basin. Conservation status and measures for species protection, conservation, and restoration at the national, regional, and global levels are presented.