Ecological Research最新文献

Appropriate management of wildlife requires sound knowledge and high-quality data about species distributions, abundance, and trends in numbers. From a legal standpoint, Article 12 of the European “Birds” Directive requires Member States to report on breeding populations sizes. Acquiring such data is difficult owing to the wide distribution of most species and the multispecies nature of surveys. We relied on a stratified two-stage spatial sampling design to assess breeding population size of waterbirds in European France. The data come from 2428 grid cells of 500 m × 500 m surveyed by territory or spot mapping three times at one-month interval between 15 March and 15 June during the springs of 2021 or 2022. Individual bird location within each grid cell and their breeding behavior were recorded. A total of 6938 grid cell visits were undertaken, yielding 64,731 observations accounting for 132,292 individuals. These data are primarily aimed to assess the breeding population size of the 25 most common waterbirds (the population size estimates will be presented in a future article). However, because the location and time of observation of all individuals, as well as their behavior, are recorded, questions such as intra- and interspecific distribution rules, or habitat selection processes, can be addressed with this dataset too. As observers were also incited to record all other species among Anatidae, Rallidae, Charadriiforms and Podicipediforms, this dataset also provides robust original data on exotic and rare birds. The detailed Metadata and complete data set are available in MetaCat in JaLTER at https://jalter.diasjp.net/data/ERDP-2025-02.

Describing the population abundance of species remains a fundamental challenge in ecology, particularly in soil ecosystems. While the preferred habitats of moles—top predators in the soil food web—are well documented in open areas such as cultivated lands and grasslands, few studies have focused on mountain forests, where assessing mole abundance is complicated by thick layers of plant leaf litter and complex topography. Additionally, many monoculture conifer plantations in Japan are poorly managed, potentially resulting in compacted soil that is less suitable for moles compared to natural broad-leaved forests. Here, we aimed to quantify the relative abundance of the lesser Japanese mole (Mogera imaizumii) in the mountain forests of Yamagata, Japan, by carefully searching for mole tunnels along 29 census routes (unpaved mountain trails) over 7 months. Although tunnels were detected on most routes (75.9%) regardless of forest type, tunnel density (tunnels/km) was lower in cedar (Cryptomeria japonica) plantations than in natural oak forests. The variation in tunnel density was positively related to earthworm biomass, highlighting the importance of earthworms as a food source. Lower earthworm biomass was associated with either higher soil hardness or higher soil moisture; however, only soil moisture tended to be higher in plantations. As cedars are typically planted in moist environments, the reduced mole abundance in these plantations may be related to the specific soil conditions of cedar plantations. These results demonstrate that mole abundance varies significantly across forest sites in response to soil environments.

We employed stable isotope ratio analysis to quantitatively assess the feeding behaviors of individual macaques within a wild group of Japanese macaques (Macaca fuscata). The primary objective was to evaluate macaque's feeding habits at the individual scale and to clarify the relationship between feeding habits and social factors, including age, sex, and social rank. The study population consisted of the Main group of Japanese macaques on Koshima Island. We collected 78 body hair samples and 29 food resource samples for isotopic analysis. The variability in carbon, nitrogen, and sulfur isotope ratios among individuals in the Main group has ranges of 5.5‰, 6.5‰, and 6.8‰, respectively. Furthermore, the Bayesian mixture model revealed that there were individual differences in the utilization of forest-derived (62.3%–90.5%), marine-derived (6.1%–27.6%), and human-derived (1.7%–23.4%) food resources, driven by the effect of sex, rank, and year. These findings particularly emphasize the utility of sulfur stable isotope ratios and demonstrate how the combined use of three stable isotope ratios enables effective analysis of the relationships between Japanese macaques and their food resources. Furthermore, our results provide a valuable opportunity for the advancement of future research that integrates stable isotope approaches with field investigations. This study not only highlights the applicability of sulfur isotope ratios as a tool for uncovering the use of marine resources by primates in other regions but also shows the potential of using isotopic techniques to distinguish human-derived resources, such as wheat, and to develop strategies for managing crop-raiding by macaques.

Soil carbon, phosphorus, and nitrogen are crucial components that influence the stability of herbaceous plant communities in desertified land restoration. However, there is a dearth of data on the variables that impact the stability of herbaceous communities at various stages of restoration. This study investigated the variables of soil and plant communities on desertified land with varying recovery periods (recovery time less than 10 years, 10–20 years, and more than 20 years) to examine the alterations in the stability of herbaceous communities and the influence of soil nutrients on these changes. Our results indicated that the stability of herbaceous communities exhibited a positive correlation with recovery time. Further research suggests that total carbon (TC) and available nitrogen (AN) levels of soil significantly influenced the herbaceous community's stability when the recovery period was less than 10 years. Total nitrogen (TN) and TC levels of soil affected the community's stability when the recovery period ranged from 10 to 20 years. When the duration of recovery surpassed 20 years, available potassium (AK) in soil significantly impacted the community's stability. This suggested that soil nutrients influence the stability of the herbaceous community. Our findings suggest that soil nutrition is a crucial factor in the initial phase of ecological restoration on desertified land. These findings offer empirical evidence for comprehending the stabilizing mechanism of herbaceous communities in desertified land and provide theoretical backing for ecological restoration methods.

Brittle stars are marine invertebrates that often dominate the seafloor. Their global distribution and abundance make them useful as marine environmental bioindicators. Despite their importance, however, there is limited availability of data on brittle star specimens in Japan. In this study, we focused on Sagami Bay, one of the oldest Japanese marine areas for the study of brittle stars, and organized the data from the specimens collected there. This collection included specimens collected between 2005 and 2021, comprising a total of 695 samples, which were identified as 108 species. All data are deposited in the Global Biodiversity Information Facility (GBIF) through the Japan Node of GBIF and are thus accessible via the GBIF portal under the Creative Commons Attribution 4.0 International license. The Metadata for this abstract published in the Data Article section of the journal are available in MetaCat in JaLTER at https://jalter.diasjp.net/data/ERDP-2025-01.

Malayan tapir is the only extant Asian species in the family Tapiridae, which is endangered and threatened by the risk of inbreeding from population structure. To elucidate the demographic and evolutionary history of the tapirs in Southeast Asia (SEA), this study analyzed whole-genome data from 10 individuals for historical effective population size (Ne) inference using sequentially Markovian coalescent (i.e., PSMC, MSMC, MSMC2), folded site frequency spectrum (i.e., Stairway Plot 2), and their hybrid SMC₊₊. The results revealed that tapir Ne ranged from 6000 to 12,000 in the last glacial period but decreased to <2000 in recent times. Genomic analysis and population split time analysis (PSMC and SMC₊₊) supported a population divergence (Fst > 0.25) between the Sumatran and mainland SEA tapirs 10–6 kya. Subsidence of Sundaland and rainforest reduction were the major drivers for Ne decline. The timing of the population split corresponded well with the inundation of the Straits of Malacca to present-day levels by rapidly rising sea levels ~11 kya. The results of this study, as well as contemporary geographical isolation, support the subspecies status of the Sumatran population. This will have implications for the ex-situ conservation practices that may have produced hybrids of the isolated populations.

Passive acoustic monitoring (PAM) has recently been developed and used for long-term and/or large spatial scale surveys. PAM is expected to be one of the most efficient methods for assessing species distribution and examining the factors affect it, helping identify important areas for biodiversity conservation and inform the management plan. In this study, we tested the feasibility of the PAM for monitoring bird species and revealed some critical points to consider in improving or developing more widely applicable PAM. We conducted PAM in the subtropical forest landscape of Amami-Oshima Island, Japan, which harbors rich biodiversity (over 100 species), including endangered and/or endemic plants and animals. Nine endemic forest bird species were detected across recording locations. The effects of environmental factors on the four bird species were analyzed, excluding the five species that were commonly detected and did not require occupancy modeling. Different environmental factors influenced the occupancy probability of the four species examined according to their habitat preferences, which is consistent with previous studies. Our results suggest that the combination of PAM and occupancy model enables us to identify the bird's spatial occupancy pattern, associated environmental factors, and the important areas that should be protected for conservation. PAM is a relatively low-cost and non-invasive method that can be applied in various monitoring of biodiversity conservation areas.

The biodiversity crisis driven by anthropogenic pressures significantly threatens marine ecosystems. The rate of climate change and anthropogenic impacts outpace our traditional observation tools' capabilities, underscoring the urgency for new assessment methods. Environmental DNA (eDNA; DNA traces released by organisms) metabarcoding, a non-invasive method widely developed over the last decade, represents a promising biomonitoring tool thanks to a large spatio-temporal coverage, high detection of rare species and its time and cost-effectiveness. However, capturing fish diversity using eDNA requires genetic reference databases, currently lacking. Improving reference databases relies on opportunistic sampling enabling the reporting of sequences for new species. The data provided here consists of barcoding 86 species of fishes over the 12S mitochondrial DNA gene. We generated 156 sequences of the mitochondrial 12S gene adapted to the “Teleo” barcodes from fishes sampled in the Bay of Biscay (BoB; Northeast Atlantic, France) between 2017 and 2019. In addition, we provided each individual the barcode details (Genbank accession number, chromatograms), a photograph, 5 ecomorphological measures and 11 life-history traits documenting ecological functions (e.g., dispersion, habitat use, diet). Furthermore, we provided the sampling metadata (e.g., date, time, gear, coordinates, depth) and environmental variables measured in situ (e.g., conductivity, water/air temperature). This data set is valuable to improve the Northeast Atlantic eDNA genetic database, thus helping to better understand the effects of environmental forcing in the BoB, a transition zone housing mixed assemblages of boreal, temperate, and subtropical fish species susceptible to display variability in functional traits to adapt to changing conditions. The detailed Metadata for this abstract published in the Data Article section of the journal is available in MetaCat in JaLTER at https://jalter.diasjp.net/data/ERDP-2024-09.

A glacial relict, a remnant of a cold-adapted species or population from a postglacial retreat, is essential for understanding the formation processes of present-day vegetation. Although past distributions have been reconstructed for several woody species in Japan, few studies have focused on the cold-adapted woody species that survive in the Japanese Archipelago. Betula costata Trautv., a species considered a glacial relict, is a common canopy tree in the cool-cold temperate forests in Northeast Asia. However, B. costata is rare and has a disjunct distribution in the Japanese Archipelago, and the reasons for its rarity and disjunction in Japan remain poorly understood. Therefore, we investigated the distribution of B. costata in Northeast Asia since the last glacial maximum (LGM; between ca. 27,000 and 19,000 years ago) using species distribution models (SDMs). We tested the working hypothesis that B. costata was once abundant in the Japanese Archipelago during the LGM. However, postglacial climate warming caused it to become a disjunct and relict. Two types of SDMs, Maxnet and Random Forest, predicted suitable habitats for the species with three time periods: The LGM, mid-Holocene, and present. The resulting maps of suitable habitats during the LGM showed extensive distribution across continental Asia and the Japanese Archipelago. By the mid-Holocene and the present, suitable habitats expanded northward in continental Asia but retreated in the Japanese Archipelago due to increases in the minimum coldest quarter temperature and precipitation. These simulation results support the hypothesis that the Japanese population of B. costata is a glacial relict.

Recognizing and maintaining locally rooted human–nature interactions is essential for utilizing ecosystem services. Although the general public's awareness of biodiversity and ecosystem services has been examined using various proxies, it remains unclear how local governments—key sectors in creating conservation policies—appreciate them within a solid local context. Here, we focused on the “city flower,” an official symbolic species of Japanese cities, as a new proxy for measuring governmental attitudes toward biota and its services. We aimed to capture temporal changes in the awareness of species with locally relevant value at the city government level by examining the changes in city flowers over more than half a century. Data from the official websites of municipalities, including the names, the adoption years, and the reasons for adoption, revealed two major periods of adoption, with a notable increase in species diversity in and after 1993. This increase could be attributed to a recent reduction in bias toward popular flowers and growing interest in alternative, less popular flowers. Analysis of the reasons for adoption suggested that the temporal change in adopted flower species was related to the increasing emphasis on species with an explicit local context, especially those with instrumental value to the city. Our findings indicate the tendency for local governments to increasingly recognize their biocultural backgrounds and the ecosystem services of plants within their regions. The growing awareness of the local governments regarding their biocultural background is a positive sign for the conservation of biodiversity and ecosystem services.