TreeGOER: A database with globally observed environmental ranges for 48,129 tree species

Understanding sustainability of woody species suitability zones on the Loess Plateau for optimal creation zone selection in response to future climate change

Climate change has profound implications for the distribution of suitable habitats for woody species. In this study, we assessed the optimal distribution thresholds for twelve woody species on the Loess Plateau using the Maximum Entropy (MaxEnt) model, incorporating sample points of tree species alongside relevant environmental variables. We analyzed the sustainability of potentially suitable zones and proposed a framework for selecting a regulatory model to establish the most suitable creation zones in response to future climate change. The results indicated that: (1) The distributions potentially suitable for Platycladus orientalis and Pinus tabuliformis were predominantly influenced by mean annual temperatures, whereas Pinus armandii and Quercus aliena var. acutiserrata exhibited optimal conditions at temperatures around -4 °C. Both Hippophae rhamnoides and Larix gmelinii var. principis-rupprechtii had suitable threshold precipitation levels exceeding 200 mm, with optimal thresholds surpassing 250 mm. (2) Most high-suitability zones for woody species across various future climate scenarios were primarily located in southern regions, including examples such as Betula platyphylla Sukaczev, Platycladus orientalis, Pinus sylvestris var. mongholica. Some of these high-suitability areas displayed insular and linear distributions, notably Larix gmelinii var. principis-rupprechtii, Quercus aliena var. acutiserrata, Salix cheilophila. (3) There was no southward shift in the northern boundary of the sustainability zones for any woody species across the different scenarios. Betula platyphylla and Salix babylonica exhibited the broadest distribution of sustainability zones. (4) The most suitable areas for the establishment of woody species were primarily found in the western, southern, and eastern regions, whereas the northern and central areas were less favorable for tree growth. Among the scenarios analyzed, SSP585 presents the most extensive distribution area. This study is expected to improve the distribution structure of woody species and the implementation of management policies.

Accelerated succession in Himalayan alpine treelines under climatic warming

Understanding how climate change influences succession is fundamental for predicting future forest composition. Warming is expected to accelerate species succession at their cold thermal ranges, such as alpine treelines. Here we examined how interactions and successional strategies of the early-successional birch (Betula utilis) and the late-successional fir (Abies spectabilis) affected treeline dynamics by combining plot data with an individual-based treeline model at treelines in the central Himalayas. Fir showed increasing recruitment and a higher upslope shift rate (0.11 ± 0.02 m yr-1) compared with birch (0.06 ± 0.03 m yr-1) over the past 200 years. Spatial analyses indicate strong interspecies competition when trees were young. Model outputs from various climatic scenarios indicate that fir will probably accelerate its upslope movement with warming, while birch recruitment will decline drastically, forming stable or even retreating treelines. Our findings point to accelerating successional dynamics with late-successional species rapidly outcompeting pioneer species, offering insight into future forest succession and its influences on ecosystem services.

Boosting biodiversity monitoring using smartphone-driven, rapidly accumulating community-sourced data

Comprehensive biodiversity data is crucial for ecosystem protection. The Biome mobile app, launched in Japan, efficiently gathers species observations from the public using species identification algorithms and gamification elements. The app has amassed >6 million observations since 2019. Nonetheless, community-sourced data may exhibit spatial and taxonomic biases. Species distribution models (SDMs) estimate species distribution while accommodating such bias. Here, we investigated the quality of Biome data and its impact on SDM performance. Species identification accuracy exceeds 95% for birds, reptiles, mammals, and amphibians, but seed plants, molluscs, and fishes scored below 90%. Our SDMs for 132 terrestrial plants and animals across Japan revealed that incorporating Biome data into traditional survey data improved accuracy. For endangered species, traditional survey data required >2000 records for accurate models (Boyce index ≥ 0.9), while blending the two data sources reduced this to around 300. The uniform coverage of urban-natural gradients by Biome data, compared to traditional data biased towards natural areas, may explain this improvement. Combining multiple data sources better estimates species distributions, aiding in protected area designation and ecosystem service assessment. Establishing a platform for accumulating community-sourced distribution data will contribute to conserving and monitoring natural ecosystems.

Forestry trials and species adaptability to climate change

Most climate change analyses of extinction risk rely on species' climatic requirements determined from only their natural distributions. Many tree species can grow successfully under climatic conditions distinctly different from those of their natural distributions. Gathering together results from these introduction trials would help to assess the importance of this climatic adaptability for different tree species.