A review of the impacts of four identified major human disturbances on the habitat and habitat use of wild giant pandas from 2015 to 2020

Anthropogenic Disturbance and Climate Change Impacts on the Suitable Habitat of Sphenomorphus incognitus in China

Estimating the impacts of anthropogenic activities and climate change on species' spatial distributions is crucial for conservation. In this study, based on 62 valid occurrence records of Sphenomorphus incognitus and 24 environmental factors (19 climate factors, 4 topographic factors, and 1 human activity factor), we utilized the biomod2 combined model platform to predict suitable habitats for S. incognitus under two current scenarios (Scenario 1: natural state; Scenario 2: human interference state) and two future climate scenarios (SSP1-2.6 and SSP5-8.5) in 2050s and 2090s. The mean true skill statistic (TSS) and the area under the receiver operating characteristic curve (AUC) suggested that the ensemble model yield more precise predictions than those of individual models. Rainfall and slope were identified as the most important factors influencing S. incognitus distribution. Human disturbance has significantly reduced suitable habitat by 44.13 × 104 km2, which is a decrease in 23.95% compared to natural conditions. Spatial analysis revealed substantial fragmentation of suitable habitat due to human activities. The incorporation of anthropogenic factors into the analysis of future climate scenarios has revealed that the area of suitable habitat exhibits divergent trends. Two distinct scenarios have been identified, each of which results in a reduction in the area of the region by 29.58 × 104 km2 and an increase by 27.04 × 104 km2, respectively, by the year 2090. The primary influence persists in human activities. The centroid of suitable habitat shifted toward the southeast under SSP1-2.6 and toward the northwest under SSP5-8.5. Our findings highlight the significant impact of anthropogenic factors on S. incognitus habitat and emphasize the need for conservation measures. Future research should incorporate additional socioeconomic data to further investigate the effects of human disturbance on this species.

Generation and characterization of giant panda induced pluripotent stem cells

The giant panda (Ailuropoda melanoleuca) stands as a flagship and umbrella species, symbolizing global biodiversity. While traditional assisted reproductive technology faces constraints in safeguarding the genetic diversity of giant pandas, induced pluripotent stem cells (iPSCs) known for their capacity to differentiate into diverse cells types, including germ cells, present a transformative potential for conservation of endangered animals. In this study, primary fibroblast cells were isolated from the giant panda, and giant panda iPSCs (GPiPSCs) were generated using a non-integrating episomal vector reprogramming method. Characterization of these GPiPSCs revealed their state of primed pluripotency and demonstrated their potential for differentiation. Furthermore, we innovatively formulated a species-specific chemically defined FACL medium and unraveled the intricate signaling pathway networks responsible for maintaining the pluripotency and fostering cell proliferation of GPiPSCs. This study provides key insights into rare species iPSCs, offering materials for panda characteristics research and laying the groundwork for in vitro giant panda gamete generation, potentially aiding endangered species conservation.

Synthesis of giant panda habitat suitability evaluations

Degradation, fragmentation, and habitat loss significantly threaten the survival of giant pandas (Ailuropoda melanoleuca). Habitat suitability evaluations (HSEs) represent a crucial component of giant panda habitat research. However, a systematic review of HSE research on giant pandas has not been conducted in recent years. To make up for that, we synthesised HSE research on giant pandas publicated from 2013 to 2022 and conducted a comprehensive analysis of the evaluation scale, evaluation methods, and research findings. We found a correlation between the geographical distribution of giant pandas and HSE-based studies on giant pandas. Furthermore, we observed a trend towards interdisciplinary and large-scale research. Although the evaluation accuracy has improved compared to that of earlier work, some limitations still remain, such as concentrated evaluation areas, incomplete indicators, and outdated data. Current HSE research on giant pandas helps determine suitable habitat distributions, facilitating protection strategies and management planning for protected areas. We suggest that future research should prioritize those unexplored or under-evaluated areas, incorporate a broader range of microenvironmental indicators, and update data resources and methodologies. This study bridges the gap in systematic reviews on HSEs of the giant panda and provides valuable references and recommendations for future research as well as the protection and management of giant panda habitats.

Integrated framework for dynamic conservation of bamboo forest in giant panda habitat under climate change

Climate change presents formidable challenges to forest biodiversity and carbon storage. Bamboo forests will be affected particularly in Southwest China's mountainous regions. Bamboo serves as not only a key food resource and habitat for giant panda Ailuropoda melanoleuca but also a potential carbon sink due to its rapid energy-to-matter conversion capability. We employ the MaxEnt model to project the distribution shifts of 20 giant panda foraged bamboo species in Sichuan Province under future climate scenarios, utilizing climate data of 30m resolution. Based on the changes in the diversity and distribution area of bamboo communities caused by climate change, the changing of giant pandas' food resources and the carbon storage of bamboo forests were calculated. The results indicated that the area of bamboo communities is projected to expand by 17.94%-60.88% more than now by the end of the 21st century. We analyzed the energy balance between the dietary needs of giant pandas and the energy provided by bamboo. We predicted that bamboo communities from 2000 to 2150 could support the continuous growth of the giant panda population (6533 wild individuals by 2140-2150 in an ideal state in Sichuan province). However, the species diversity and carbon storage of bamboo forests face out-of-sync fluctuations, both temporally and spatially. This is a critical issue for subalpine forest ecosystem management under climate change. Therefore, we propose a dynamic conservation management framework for giant panda habitats across spatial and temporal scales. This framework aims to facilitate the adaptation of subalpine forest ecosystems to climate change. This innovative approach, which integrates climate change into the conservation strategy for endangered species, contributes a conservation perspective to global climate action, highlighting the interconnectedness of biodiversity preservation and climate mitigation.

Assessment of stress levels and reproductive condition in giant pandas: insights from hair, faecal and saliva samples

Concerted conservation efforts have brought the giant panda (Ailuropoda melanoleuca) back from the brink of extinction, but pandas continue to face anthropogenic threats in the wild and breeding success in captivity remains low. Because stress can have detrimental impacts on reproduction, monitoring stress- and sex-steroid levels would help assess the effectiveness of conservation mitigation measures in panda populations as well as monitor the welfare and reproductive health of captive animals. In this proof-of-concept study, we used faecal sex steroid and cortisol concentrations (n = 867 samples collected from five males and five females at Beijing Zoo every 4 days over the course of 12 months) as a reference to investigate if testosterone, estradiol, progesterone and cortisol can be meaningfully measured in panda hair (n = 10) using radio-immuno-assays. Additionally, we calculated the ratio of testosterone to cortisol (T:C ratio) for each male, which can provide a biomarker of stress and physical performance. Our findings revealed distinct monthly variations in faecal sex-steroid and cortisol concentrations, reflecting reproductive seasonality and visitor-related stress among individual pandas. Notably, the oldest male had a significantly lower T:C ratio than other males. Our results confirm that the level of sex steroids and cortisol can be assayed by panda hair, and the hair cortisol concentrations correlate significantly with that in faeces with one month lag behind (r = 0.68, P = 0.03). However, the concentrations of hormones detected in saliva are lower than those in faeces by two orders of magnitude, making it difficult to ensure accuracy. By assessing the applicability of hair, faecal and salivary sampling, we can infer their utility in monitoring the reproductive status and acute and chronic stress levels of giant pandas, thereby providing a means to gauge the success of ongoing habitat restoration efforts and to discuss the feasibility of sample collection from wild populations.

A review of research advances and perspectives on the habitat ecology of Sichuan and golden takins: 2001 to 2022

The Sichuan takin (Budorcas tibetanus) and the golden takin (Budorcas bedfordi) are endemic to China. Studies of their habitat ecology have attracted attention, but dedicated reviews of the topic have not been published. To fill this gap, research advances on the habitat ecology of these takin species were reviewed based on published journal papers from 2001-2022, covering habitat selection and use, as well as habitat assessment and protection. Habitat selection and use by the takins received the most frequent reports in a few protected areas, such as the Tangjiahe Nature Reserve in Sichuan and the Foping Nature Reserve in Shaanxi. Higher herb cover characterized some of the Sichuan takin habitats, while some of the golden takin population exhibited seasonal altitude migration. The focus on habitat assessment and protection differed between the two species. Studying the habitat of the Sichuan takin involves the relationship between its habitat and the protected areas and habitat status in various ranges while studying the habitat of the golden takin involves habitat distribution and change, protection effects, and corridor planning. Some issues worthy of consideration in future research are proposed, including basic habitat information, impacts of human disturbances, habitat restoration, and theoretical, independent, and comprehensive studies on both takins. Habitat conservation frameworks should be formulated for both takins to improve protection and restoration effects. This review provides convenient information to help understand the habitat characteristics of the two takins and is a reference for future research.

The Science Underlying Giant Panda Conservation Translocations

The giant panda (Ailuropoda melanoleuca) is the flagship species of animal conservation worldwide, and the number of captive pandas reached 673 in 2021. According to the Fourth National Survey Report on the Giant Panda, there are 1864 wild pandas, segregated into 33 local populations, and 25 of these populations are too small to be self-sustaining. In addition to the conservation and restoration of panda habitats, conservation translocations, an approach that has been shown to be effective in slowing or reversing biodiversity loss, are highly desirable for panda conservation. The captive-bred panda population has grown rapidly, laying the foundation for releasing captive-bred pandas into the wild. This paper reviews the scientific advances in conservation translocations of pandas. Studies have shown that before translocation conservation programs are implemented, we should determine what factors are causing the depletion of the original population at the release site. The selection of suitable release sites and individuals will help to improve the survival rate of released individuals in the wild. Pre-release training and post-release monitoring are essential to ensure successful releases. We also see the great potential for increasing applications of Adaptive Management to improve the success of giant panda conservation translocation programs. This review provides theoretical guidance for improvement of the success rate in conservation translocations for captive pandas, and uses the panda as a model species to provide a global reference for the conservation translocations of rare and endangered species.

A review of the habitat restoration of giant pandas from 2012 to 2021: Research topics and advances

The giant panda (Ailuropoda melanoleuca) is a flagship species in nature conservation. Habitat degradation and fragmentation threaten the sustainable survival of giant pandas, and thus degraded habitats need to be restored and fragmented habitats require connection. In the past ten years, some new studies have emerged on the habitat restoration of giant pandas, yet no specialized reviews of this topic have been published. This paper reviews the habitat restoration of giant pandas based on related articles published between 2012 and 2021. Three principal research topics are identified and summarized: restoration effect, restoration requirements, and restoration considerations. The review demonstrates that some measures, such as protection projects and policies, controlling human disturbances and impacts, and natural recovery, contribute to the habitat restoration of giant pandas. Many issues related to artificial forests need to be addressed to clarify their role in habitat restoration. Many habitats with clear locations and types need restoration, especially those that are disturbed or threatened by human activities and some that are disturbed by natural disturbances such as earthquakes. To integrate consideration factors, a reference habitat should be established and well described. In addition, social and economic factors should not be ignored. More targeted studies of the habitat restoration of giant pandas are urgently needed, including theoretical, cross-scale, interdisciplinary, multi-factor, and long-term monitoring studies. This review provides a reference for future research work and a source of information for future restoration of giant panda habitat.

Assessing the effect of roads on mountain plant diversity beyond species richness

A comprehensive understanding of the effects of mountain roads on plant diversity is critical to finding the most effective solutions for managing this particular driver. Little is known, however, about the simultaneous effects that road have on the multiple facets of biodiversity, although roads are considered to be one of the major disturbances in the Qionglai mountain range. In this study, we analyzed the impact of roads on the multiple facets of plant diversity (taxonomic, functional and phylogenetic diversity) in the study area using Hill numbers by comparing plant diversity between roadside and interior plots at the landscape scale, then, we used linear mixed models to analyze the effect of mountain roads on the multiple facets of plant diversity along an elevational gradient. The results showed that the roadside plots lacked 29.45% of the total number of species with particular functional traits (such as a relatively high specific leaf area (SLA), a relatively low leaf dry matter content (LDMC) and relatively old clades) and exclusively contained 14.62% of the total number of species. Compared with the interior community, the taxonomic, functional and phylogenetic diversity of roadside community decreased by no more than 26.78%, 24.90% and 16.62%, respectively. Taxonomic and functional diversity of dominant and common species showed greater changes to road disturbances, while rare species showed the greatest change in phylogenetic diversity. Taxonomic homogenization of roadside communities was accompanied by functional and phylogenetic homogenization. Additionally, the impact of roads on these three facets of plant diversity showed the characteristics of peak clipping along the elevation gradient. Our findings highlight the negative impact of roads on the taxonomic, functional and phylogenetic diversity of the Qionglai mountain range, as roads promote communities that are more similar in taxonomic, functional, and phylogenetic composition, and to a greater extent contributed to compositional evenness. These effects tend to be functionally and phylogenetically non-random, and species in some clades or with some functional traits are at higher risk of loss. Our results are important for the conservation and management of nature reserves, especially for local governments aiming to create new infrastructure to connect natural mountainous areas.

Temporary Stability Characteristics and Influencing Factors of Abies faxoniana-Dominated Communities in the Wanglang Nature Reserve

Specialized studies on the stability of Abies faxoniana (AF) communities are lacking. In order to fill this gap, a field survey of AF communities was conducted in the Wanglang Nature Reserve. Temporary stability is the possibility of the most dominant species to remain unchanged in a short period, reflecting the persistence of community stability to some extent. In this study, the temporary stability characteristics and influencing factors of the AF-dominated communities were analyzed. The results showed that the dominance of AF over the second dominant tree species became more pronounced as the temporary stability of the AF-dominated communities increased. Communities with the largest temporary stability value were dominated by AF alone. Furthermore, temporary stability had a significant linear positive relationship with the number of AF trees but not the AF size. There was no significant difference in the temporary stability between communities with and without large AF trees. It was concluded that with the increase in temporary stability, AF became more impossible to be replaced by other tree species in the short term, and the number of AF trees significantly affected the temporary stability of the AF-dominated communities. This study provides new insights into the stability characteristics of AF communities.

Environmental drivers of sympatric mammalian species compositional turnover in giant panda nature reserves: Implications for conservation

The charismatic giant panda (Ailuropoda melanoleuca) is an iconic species of wildlife conservation worldwide. As the most effective measure to protect giant pandas and their habitats, China has established 67 giant panda nature reserves (GPNR) during the last five decades, which also bring benefits to many sympatric medium- and large-bodied mammals (MLM). To better inform the planning of the GPNR network with the view of preserving regional MLM diversity, we investigated the zeta diversity (a novel index to measure species compositional turnover considering the contributions of both rare and common species) patterns (i.e. zeta decline and retention rate curve) of MLMs across 40 GPNRs. The effects of species' body mass and conservation status on the zeta diversity patterns were tested. Further, we applied the multi-site generalized dissimilarity modelling (MS-GDM) framework to explore the impacts of environmental and geographic distances on MLM turnover. The results indicated that there are a core set of 17 MLM species sympatric with the giant panda in the GPNRs. Species' body mass can affect the patterns of zeta decline and retention rate curves, and the number of large-bodied species shared by multiple GPNRs is higher than that of medium-bodied species across zeta orders. The MS-GDM revealed the important roles of difference in habitat heterogeneity and spatial distance between GPNRs in driving MLM turnover. Consequently, we advocate maintaining and increasing the diversity of (natural) habitats in GPNRs to protect giant panda's sympatric MLM diversity. The government should consider optimizing the GPNR network (e.g. incorporating multiple small GPNRs into one single large reserve) to capture the most turnover of MLMs, and the newly-established Giant Panda National Park is relevant to fulfilling this long-term goal.

Understanding Species–Habitat Associations: A Case Study with the World’s Bears

Habitat modeling is one of the most common practices in ecology today, aimed at understanding complex associations between species and an array of environmental, bioclimatic, and anthropogenic factors. This review of studies of seven species of terrestrial bears (Ursidae) occupying four continents examines how habitat models have been employed, and the functionality of their predictions for management and conservation. Bear occurrence data have been obtained at the population level, as presence points (e.g., sign surveys or camera trapping), or as locations of individual radio-collared animals. Radio-collars provide greater insights into how bears interact with their environment and variability within populations; they are more commonly used in North America and Europe than in South America and Asia. Salient problematic issues apparent from this review included: biases in presence data; predictor variables being poor surrogates of actual behavioral drivers; predictor variables applied at a biologically inappropriate scale; and over-use of data repositories that tend to detach investigators from the species. In several cases, multiple models in the same area yielded different predictions; new presence data occurred outside the range of predicted suitable habitat; and future range projections, based on where bears presently exist, underestimated their adaptability. Findings here are likely relevant to other taxa.

Integrating Livestock Grazing and Sympatric Takin to Evaluate the Habitat Suitability of Giant Panda in the Wanglang Nature Reserve

Simple Summary

Giant pandas are facing the threat of habitat degradation. Both grazing livestock and sympatric animals have certain impacts on the giant panda habitat. This study evaluated the habitat suitability of giant panda in Wanglang Nature Reserve by simultaneously investigating livestock grazing and sympatric takin. Results for the giant panda habitat in Wanglang are not optimistic, and the extensive overlap of suitable habitats for livestock, takin and panda makes the situation worse.

Abstract

Habitat suitability provides essential information for the management of protected species. However, studies that jointly consider the impacts of human disturbance and sympatric animals in habitat suitability assessments of giant panda are limited, which may overestimate the habitat status. To address this issue, we evaluated the habitat suitability of giant panda in Wanglang Nature Reserve by simultaneously investigating livestock grazing and sympatric takin via MAXENT, a new attempt at the assessment of the habitat suitability of giant panda. We focused on describing the habitat suitability of giant panda and determining the habitat overlap between livestock, takin, and panda to evaluate the impacts of livestock grazing and sympatric takin on the suitable giant panda habitat. Results revealed that only 16.33% of the area in Wanglang was suitable giant panda habitat, of which 67.66% was shared by livestock, and 97.99% of the remaining suitable panda habitat not shared by livestock was revealed to be shared by takin. The results indicate an unfavorable habitat status of giant panda in Wanglang, with the potential extensive habitat overlap between livestock, takin and panda exerting further pressure. Thus, to effectively protect giant pandas and their habitats, grazing activity should be controlled. Furthermore, to accurately protect sympatric animals, the monitoring of panda and takin activities in the overlapping areas must be maintained.