Ecology and Evolution最新文献

Arid and semiarid regions constitute the primary distribution areas of desert ecosystems, and the long-term, multifactor dynamic assessments of ecological quality can provide a scientific basis for the regional construction and sustainable development of desertified steppe ecosystems. To address the ecological vulnerability and monitoring needs of the Yinshan Mountains, we constructed a new MODIS-based Remote Sensing Ecological Indicator (MODIS RSEI) based on MODIS data from 2001 to 2023. This indicator integrates greenness (SAVI, Soil Adjusted Vegetation Index), humidity (SWCI, Surface Water Capacity Index), dryness (NDBBI, Normalized Difference Bareness and Built-up Index), heat (LST, Land Surface Temperature), as well as a salinity index (CSI, Comprehensive Salinity Index). Additionally, an optimal parameter geographic detector (OPGD) was employed to analyze the driving factors affecting ecological quality and their interactions. The results show that (1) the MODIS RSEI in the Yinshan Mountains exhibited a spatial pattern of "low in the west and high in the east," fluctuating temporally between poor (0.20-0.40), moderate (0.40-0.60), and good (0.60-0.80) levels; (2) analysis of the Hurst index indicated that 62.53% of the MODIS RSEI in the Yinshan Mountains exhibited sustainable stability; and (3) single-factor detection based on the OPGD showed that the spatial differentiation of MODIS RSEI was mainly affected by NPP (q = 0.837), precipitation (q = 0.474), and grazing intensity (q = 0.416). The interaction of multiple factors was significant, and the interaction of any two driving factors was greater than the influence of a single driving factor on the spatial differentiation of the Yinshan Mountains. This study provides a methodological framework and empirical evidence to support ecological conservation planning in the Yinshan Mountains, with potential applications in other arid and semiarid regions.

Orchids are traded globally, where wild populations can be threatened by overharvesting, habitat loss, and climate change. Many orchid species lack ex situ protection, such as botanical gardens, making in situ genetic studies of wild populations critical to inform conservation plans. Taiwan is a center for orchid diversity and has witnessed declines in wild orchids. Holcoglossum pumilum, an island endemic epiphytic species, is popular among citizen scientists and shows potential for public engagement in biodiversity conservation. This study aims to evaluate the genetic diversity, population structure, and adaptive potential of wild Holcoglossum pumilum in Taiwan, not only to serve as an example for public outreach but also to inform conservation policy. We collected 64 plants from 18 sites across Taiwan and used ddRADseq to generate genome-wide SNP data. We found higher genetic diversity in southern populations than in northern ones. While evidence for genetic clustering and isolation by distance was limited, we detected significant genotype-environment associations, especially with annual precipitation. Demographic reconstructions suggested a pre-LGM expansion followed by a plateau. Contemporary Ne estimates varied by data filtering strategies but were mostly below 500. Our study demonstrates the critical role of genomic data not only in revealing the evolutionary origin of genetic diversity but also in guiding conservation plans. Specifically, we argued that the seasonal monsoon and the mountainous landscape of Taiwan may have shaped a latitudinal gradient of genetic diversity in H. pumilum. As a result, southern populations exhibit greater genetic diversity, which makes them priorities for conservation management.

Pastoralism is one of the most common land uses worldwide and has been a fundamental part of Mediterranean ecosystems for thousands of years. We aimed to investigate how this land use influences carrion ecology and species interactions among mammalian facultative scavengers in East Mediterranean habitats. We carried out an in situ "cafeteria" field experiment, placing domesticated (Bos taurus) versus native (Sus scrofa) species' carrion in both pastoral and nonpastoral areas. We monitored scavenger activity using camera traps and analyzed changes in species interactions and carrion preferences between these two habitat types. The average camera encounter rate of the three most common scavenger species was significantly higher in nonpastoral areas than in pastoral ones. Our results also showed a notable preference for boar over cow carrion by foxes (Vulpes vulpes), while wild boars (Sus scrofa) and golden jackals (Canis aureus) exhibited no significant preferences. Using Piecewise Structural Equation Modeling (PSEM), we found no significant interactions among facultative scavengers in pastoral lands, whereas most scavenger species interactions in nonpastoral areas were significant and negative. Our findings indicate a significant, though variable, impact of pastoralism on facultative scavengers. From a conservation standpoint, these results highlight the challenge of maintaining an optimal structure for the mammalian scavenger guild in mixed landscapes.

Betel nut plantations have rapidly expanded in recent decades owing to their considerable economic benefits, resulting in a significant reduction of tropical secondary rainforests, which has had substantial impacts on soil hydrological properties. However, few studies have investigated the effects of forest conversion on these properties. In this study, soil samples from secondary forests (SF) and betel nut plantations (BP) were collected to assess soil physicochemical and hydrological properties. The results showed significantly higher topsoil (0-10 cm) water content and saturated water-holding capacity in SF than in BP. However, the opposite pattern was observed in the subsurface soil layer (20-60 cm). Similarly, the 0-10 cm soil layer showed higher capillary water capacity and field capacity in SF than in BP, but this trend was reversed in the 10-60 cm soil layer. Additionally, the conversion of forests into betel nut plantations led to a reduction in saturated hydraulic conductivity. The soil hydrological properties were significantly affected by land-use change through alterations in soil properties. We found that the soil nutrient content in BP was much lower than that in SF. Besides, soil capillary porosity played a role in influencing soil water retention, accounting for 32.03% of the variation, followed by total porosity (27.04%) and soil bulk density (26.5%), whereas the soil particle composition also had a resistance to soil degradation effect on soil water retention. Together, the conversion of secondary forest into betel nut plantations not only led to soil degradation, but also has negative effects on soil water retention capacity by reducing soil porosity and increasing soil bulk density. These findings provide important insights for the management of agroecological systems in tropical regions.

This study aimed to elucidate the intra and interpopulation genetic variation of Pastor roseus in Xinjiang, China. Sequences of the mitochondrial genes COI and Cytb of 108 individuals from 10 distinct geographical populations across four regions of Xinjiang Uyghur Autonomous Region were analyzed. The mitochondrial genes were 1551 and 1143 bp in full length, respectively, and the AT content of bases was greater than the GC content. Based on the molecular variation in COI and Cytb, 62 and 69 haplotypes were detected, respectively; the average haplotype diversity (H _d) values were 0.976 ± 0.006 and 0.944 ± 0.018, respectively, and the nucleotide diversity (π) values were 0.00316 ± 0.00016 and 0.00292 ± 0.00021, respectively, indicating that there was high genetic diversity among the 10 population. Analysis of molecular variance (AMOVA) indicated that the major source of genetic variation was within the populations. Analysis of molecular signatures of neutrality indicated that Tajima's D value was not significant, but Fu's F _S was significant, suggesting that P. roseus populations have recently experienced a large population expansion, but that the populations are currently relatively stable and the selection pressure is low, The Bayesian Skyline Plot (BSP) results indicate that the expansion occurred approximately 0.0015 million years ago. Although the P. roseus currently maintains a high level of genetic diversity and population connectivity, its recent population decline and the geographical isolation risks faced by some populations cannot be ignored. To sustain its crucial ecological role as a natural enemy of locusts, future conservation strategies should focus on ensuring habitat quality, preserving migration route integrity, and facilitating gene flow among populations.

Physiological plasticity is fundamental for resisting environmental change. As climate change accelerates and environmental stressors become more frequent, understanding how habitat-forming species shift their physiology to match their environment is essential for predicting broader ecosystem responses. In this study, we examined whether prior exposure to sub-bleaching heat stress influenced the gene expression responses to a subsequent thermal challenge in a common reef-building coral. We primed Acropora corals from the World Heritage-listed Ningaloo Reef (WHNR) to acute (24 h) sub-bleaching temperatures (+5°C from the mean monthly maximum MMM, 32°C) before subjecting them to a more intense thermal challenge (+6°C from MMM, 33°C), and assessed the physiological and transcriptional responses in both naïve (no prior preconditioning) and primed corals compared to controls. Both groups mounted large gene expression responses to heat stress (33°C), which returned to baseline after a recovery period (16 h) at control temperatures (27°C, MMM), with no visible signs of physiological stress. However, primed corals showed a dampened stress response relative to naïve corals, marked by a 28% decline in differentially expressed genes and an overall reduction in intensity of expression of those genes compared to controls. Similar patterns were observed in the symbiotic partners, which showed a dampened response within the primed corals compared to the controls, despite no detectable declines in photosynthetic performance within either treatment. Our results show that short-term preconditioning of corals is associated with transcriptional dampening of key stress response genes, and that corals are capable of rapid transcriptional recovery and resilience to recurrent heat stress.

Establishing key life history traits (i.e., somatic growth rates) for sea turtles produces insights into population demography and informs conservation efforts. Despite a plethora of studies on sea turtles over the past decades, there remain significant knowledge gaps for the demography of many populations. From 2015 to 2022, we measured somatic growth for 215 foraging green turtles (Chelonia mydas) captured among three foraging areas in the Fijian Archipelago, tropical South Pacific. We modeled a mean size-specific growth rate function for this foraging aggregation that was non-monotonic decreasing with size. The mean growth rate for this foraging aggregation was 1.6 ± 0.1 cm year^-1 curved carapace length, and we found some spatial variation in growth rates across the three foraging sites (range of means = 1.1-1.8 cm year^-1), perhaps owing to differences in habitat quality and/or ontogeny-based differences in feeding ecology. Overall, the range of Fijian juvenile green turtle growth rates aligns with those reported from foraging aggregations elsewhere in the Pacific and also conforms to the general pattern of non-monotonic declining growth reported for green turtles throughout this ocean basin. Establishing foraging area-specific growth parameters for Fijian green turtles provides current estimates to inform ecological and health assessments vital to the development of future conservation plans.

Flowering is an important trait for the resilience of marine angiosperms (seagrasses) as they face rising seawater temperatures, more frequent extreme weather events, and anthropogenic disturbances. Using the seagrass Zostera marina, we applied a common garden approach to experimentally test how flowering and its underlying molecular mechanisms responded to elevated water temperature (+3°C). We focused on developmental and reproductive traits paired with florigen gene expression to gain insight into the molecular mechanism underpinning differences in flowering responses. We compared annual seedlings from two source populations (Willapa Bay along the coast and Padilla Bay in the Salish Sea, Washington, USA) to understand natural variation not only in morphological and reproductive traits but also in the gene-environment interactions governing flowering onset. At the individual and population levels, annual seedlings in the +3°C heated treatment produced more spathes and accelerated the development of inflorescences, so seeds dispersed sooner. Seedlings from Padilla Bay flowered at greater rates and earlier than those from Willapa Bay, and these differences were exaggerated by the +3°C heated treatment. A predicted repressor of flowering onset, ZmaFT9, was expressed at lower levels in the shoots grown in the +3°C heated treatment, and even more so in the Padilla Bay population, which flowered earlier than the Willapa Bay population. For two predicted floral activators, ZmaFT2 and ZmaFT4, expression increased throughout the summer regardless of population and showed no response to the temperature treatment. ZmaTFL1a, a gene predicted to be involved with downstream flowering processes, showed no significant response to the temperature treatment. Together, these results support a key role for antiflorigen (ZmaFT9) in the molecular control of flowering in Z. marina, and ZmaFT9 expression contributes to the temperature-based response of the timing of flowering onset. Impacts of elevated seawater temperature on flowering timing and spathe production, with different responses by population, have potential consequences for seed yield and variation in meadow resilience.

DNA metabarcoding offers a powerful, non-invasive tool to identify dietary composition with high taxonomic resolution, yet its quantitative accuracy and bias remain a well-recognised limitation across taxa and sample types. This universal challenge is particularly evident in herbivores, where plant material introduces additional amplification constraints. This study evaluates the accuracy of DNA metabarcoding in reconstructing the diets of sheep under controlled feeding trials involving high and low digestibility forage, using two widely used plant DNA barcodes (ITS2 and trnL). A secondary trial tested the detectability and proportional representation of a target species, Medicago sativa, when added to the diet in varying amounts (1%, 5%, 10%). ITS2 provided greater species-level resolution, while trnL showed broader taxonomic coverage but reduced precision. Both markers distinguished diet treatments effectively; however, faecal DNA showed proportional discrepancies from vegetation input, particularly under low-digestibility conditions. M. sativa was reliably detected even at 1% inclusion but was consistently overrepresented in sequence reads. Our findings highlight the strengths and limitations of DNA metabarcoding for herbivore diet studies and underscore the importance of marker choice and the effects of differential digestion biases. These findings demonstrate the need for multi-marker approaches and calibration controls in dietary studies, especially when quantitative interpretation is required. Despite limitations in quantitative accuracy, faecal DNA metabarcoding provides valuable insights into herbivore diet composition and preferences, with future refinements expected to improve its resolution and reliability for ecological monitoring and grazing management.

Cognitive flexibility and inhibitory control are core executive functions that enable animals to adapt their behaviour to variable environments. Although these abilities are extensively studied in primates, and despite a growing interest in ungulate cognition, research specifically targeting executive functions in ungulates remains limited. In this study, we compare the performance of domestic goats (Capra hircus) and sheep (Ovis aries) in a reversed-reward contingency (RRC) task. This task is traditionally used to test inhibitory control (the ability to resist a prepotent response), but it should also involve cognitive flexibility (the ability to adapt to changed contingencies). Overall, goats performed better than sheep. Two young goats met the success criterion spontaneously, and two more succeeded following corrective procedures. No sheep exceeded chance-level performance. Only younger goats solved the task, confirming that cognitive flexibility is indeed a core process in this task for ungulates. The differences between sheep and goats reflect subtle differences in their behavioural flexibility both in the social and ecological domains. These results extend comparative cognition research beyond primates, highlighting ungulates as promising models for studying the evolution of executive functions.