Spatiotemporal effects of climate on the relationship between tree diversity and forest ecosystem functioning

Worldwide, forest ecosystem functioning and plant diversity have been altered by global environmental change. Understanding the relationship between biodiversity and ecosystem functioning with long-term environmental change is important because maintaining diversity can mitigate the impacts of environmental change on ecosystem functioning. Here, I i) developed a concept that can elucidate how enhancing plant diversity may help mitigate global environmental change impacts on ecosystem functioning; ii) empirically tested this concept in natural forest systems by examining whether higher tree diversity enhances and reduces positive and negative impacts of long-term environmental change on forest biomass dynamics (biomass growth, loss, and net biomass change); iii) explored effects of spatial variations in climate on the relationship between tree functional diversity and forest biomass dynamics; and iv) investigated how spatial variations in climate mediate the impacts of long-term environmental change on tree functional composition. In order to establish the concept of how tree diversity can mitigate the impacts of global environmental change on forest ecosystem functioning, I reviewed the field of climate change effects on biodiversity-ecosystem functioning. I found mixed evidence for positive diversity effects on ecosystem functioning persistent before and after experiencing changes in climates within grassland communities, but strong support in the few studies conducted in forest ecosystems which are more stable and resilient at higher levels of diversity. I identify the importance of future research combining investigations into climate change impacts on ecosystem functionality with the B-EF. I concluded that biodiversity can hold certain potential to be a solution to mitigate environmental change impacts. Using inventory data of boreal forests of western Canada from 1958-2011, I revealed that aboveground biomass growth of species-rich forests increased with the calendar year but that of species-poor forests decreased. Moreover, species-rich forests experienced less aboveground biomass loss from tree mortality than species-poor forests. I found that the growth of species-rich forests, but not species-poor forests, was positively associated with elevated CO2. Mortality in species-poor forests increased more with decreasing water availability than species-rich forests. In contrast, growth decreased, and mortality increased as the climate warmed regardless of species diversity. The results of this study suggest that promoting high tree diversity may help reduce the climate and environmental change vulnerability of boreal forests

Functional diversity enhances dryland forest productivity under long-term climate change

乾燥地の樹木多様性が気候変動影響を緩和--樹木形質の多様性と形質特性の関係を紐解く--. 京都大学プレスリリース. 2024-04-25.Diversity and productivity go branch-in-branch: Canadian dryland forest productivity boosted by functional diversity in hard times. 京都大学プレスリリース. 2024-04-26.Short-term experimental studies provided evidence that plant diversity increases ecosystem resilience and resistance to drought events, suggesting diversity to serve as a nature-based solution to address climate change. However, it remains unclear whether the effects of diversity are momentary or still hold over the long term in natural forests to ensure that the sustainability of carbon sinks. By analyzing 57 years of inventory data from dryland forests in Canada, we show that productivity of dryland forests decreased at an average rate of 1.3% per decade, in concert with the temporally increasing temperature and decreasing water availability. Increasing functional trait diversity from its minimum (monocultures) to maximum value increased productivity by 13%. Our results demonstrate the potential role of tree functional trait diversity in alleviating climate change impacts on dryland forests. While recognizing that nature-based climate mitigation (e.g., planting trees) can only be partial solutions, their long-term (decadal) efficacy can be improved by enhancing functional trait diversity across the forest community

Virological characteristics of the SARS-CoV-2 XBB variant derived from recombination of two Omicron subvariants

In late 2022, SARS-CoV-2 Omicron subvariants have become highly diversified, and XBB is spreading rapidly around the world. Our phylogenetic analyses suggested that XBB emerged through the recombination of two cocirculating BA.2 lineages, BJ.1 and BM.1.1.1 (a progeny of BA.2.75), during the summer of 2022. XBB.1 is the variant most profoundly resistant to BA.2/5 breakthrough infection sera to date and is more fusogenic than BA.2.75. The recombination breakpoint is located in the receptor-binding domain of spike, and each region of the recombinant spike confers immune evasion and increases fusogenicity. We further provide the structural basis for the interaction between XBB.1 spike and human ACE2. Finally, the intrinsic pathogenicity of XBB.1 in male hamsters is comparable to or even lower than that of BA.2.75. Our multiscale investigation provides evidence suggesting that XBB is the first observed SARS-CoV-2 variant to increase its fitness through recombination rather than substitutions

Frugivory of the Stone Marten (Martes foina Erxl.) in Bulgaria – a review from an urban perspective

The present study reviewed frugivory characteristics of the Stone Marten (Martes foina Erxleben, 1777) in Bulgaria with special reference to cultivated plants. A total of six studies were compiled, which showed that nine species fruits (eight species of them were cultivated) and 17 genus/family-level-identified fruits (six genera of them were cultivated) were consumed by the marten

Does aversion to insects affect insecticide use? An elusive answer calls for improved methods in biophobia research

Abstract Insecticides are commonly used to control insects and other arthropods in homes (hereafter collectively referred to as ‘insects’). Although aversion to insects might encourage the use of insecticides, it is unclear whether such feelings truly influence the decision to use insecticides. We investigated the connection between feelings of disgust towards insects and the use of household insecticides. Our aim was to uncover the unexplored emotional drivers of insecticide use, in order to provide insights that might help develop new programmes to reduce exposure to household insecticides. We conducted an online survey (n = 2500) that focussed on insecticide use and disgust feelings towards six species commonly found in homes (cockroaches, ants, spiders, mosquitoes, flies and centipedes). Respondents rated their level of disgust towards these species and reported various beliefs and practices related to household insects and insect control. Approximately 70% of respondents expressed strong disgust towards these species (ratings of 6 or 7 on a scale of 1–7). More than half (53.3%) reported using aerosol insecticides in their homes in the 6 months prior to the survey. Path analyses highlighted several factors that influenced insecticide use, including infestation level, disgust intensity, lack of knowledge about arthropods and aversion to chemicals. However, the observed effect sizes were modest, particularly regarding the influence of disgust on insecticide use, which somewhat constrains our study's contribution to the understanding of the motivators driving household insecticide use. We explain how our findings potentially reflect a critical methodological limitation in the standard methods commonly used for measuring aversion in biophobia (fear of nature) research. This limitation originates from the fact that highly aversive animals often provoke extreme reactions from most participants, resulting in a very low data variation that hinders data analysis. We address this concern in the context of our findings and propose potential solutions that could pave the way for future research on how attitudes towards highly aversive animals affect individuals, society, and the relationships between people and nature. Read the free Plain Language Summary for this article on the Journal blog

<資料>京都府南部の市街地内(京都大学・宇治キャンパス)で確認されたフクロウStrix uralensisの記録

2023年8月21日の夜間，京都府南部の市街地に位置する京都大学・宇治キャンパス(京都府宇治市)構内において森林性の大型鳥類フクロウStrix uralensis(京都府の順絶滅危惧種)が観察された．これまでの宇治キャンパス構内における鳥類相報告ではフクロウの記録はなく，本報告は既存の目録に重要な1種を加えるものである．At midnight on August 21, 2023, the Ural owl (Strix uralensis: Strigiformes, Strigidae), a large predatory bird species, was observed on the Uji Campus of Kyoto University, located in the urban area of southern Kyoto Prefecture, western Japan. The Ural owl is a forest-dwelling species and is categorized as a Near-Threatened Species in the Red List of Kyoto Prefecture. There are no previous records of owls in the bird assemblages reported within the Uji Campus of the university. The present report adds an important species to the previous survey results

Species-rich boreal forests grew more and suffered less mortality than species-poor forests under the environmental change of the past half-century

Climate and other global environmental changes are major threats to ecosystem functioning and biodiversity. However, the importance of plant diversity in mitigating the responses of functioning of natural ecosystems to long-term environmental change remains unclear. Using inventory data of boreal forests of western Canada from 1958 to 2011, we found that aboveground biomass growth increased over time in species-rich forests but decreased in species-poor forests, and importantly, aboveground biomass loss from tree mortality was smaller in species-rich than species-poor forests. A further analysis indicated that growth of species-rich (but not species-poor) forests was statistically positively associated with rising CO 2 , and that mortality in species-poor forests increased more as climate moisture availability decreased than it did in species-rich forests. In contrast, growth decreased and mortality increased as the climate warmed regardless of species diversity. Our results suggest that promoting high tree diversity may help reduce the climate and environmental change vulnerability of boreal forests

A Comparison of Visual and Genetic Techniques for Identifying Japanese Marten Scats - Enabling Diet Examination in Relation to Seasonal Food Availability in a Sub-Alpine Area of Japan

We compared the reliability of visual diagnostic criteria to DNA diagnostic techniques, including newly designed primers, to discriminate Japanese marten (Martes melampus) feces from those of other sympatric carnivore species. Visual criteria proved > 95% reliable for fresh, odoriferous scats in good condition. Based upon this verification, we then examined if and how Japanese marten diet differs among seasons at high elevation study site (1500-2026 m). We also considered how intra-specific competition with the Japanese red fox (Vulpes vulpes japonica) may shape marten feeding ecology. From 120 Japanese marten fecal samples, high elevation diet comprised (frequency of occurrence) 30.6-66.0% mammals, 41.0-72.2% insects and 10.6-46.2% fruits, subject to seasonal variation, with a Shannon-Weaver index value of 2.77. These findings contrast substantially to seasonal marten diet reported in adjacent lowland regions (700-900 m), particularly in terms of fruit consumption, showing the trophic adaptability of the Japanese marten. We also noted a substantial dietary overlap with the red fox (n = 26 scats) with a Shannon-Weaver index of 2.61, inferring little trophic niche mutual exclusion (trophic niche overlap: 0.95), although some specific seasonal prey selection differences were likely related to relative differences in body size between foxes and martens. This additional information on the feeding ecology of the Japanese marten enables a better assessment of the specific risks populations face in mountainous regions

Species‐rich boreal forests grew more and suffered less mortality than species‐poor forests under the environmental change of the past half‐century

Climate and other global environmental changes are major threats to ecosystem functioning and biodiversity. However, the importance of plant diversity in mitigating the responses of functioning of natural ecosystems to long-term environmental change remains unclear. Using inventory data of boreal forests of western Canada from 1958 to 2011, we found that aboveground biomass growth increased over time in species-rich forests but decreased in species-poor forests, and importantly, aboveground biomass loss from tree mortality was smaller in species-rich than species-poor forests. A further analysis indicated that growth of species-rich (but not species-poor) forests was statistically positively associated with rising CO 2 , and that mortality in species-poor forests increased more as climate moisture availability decreased than it did in species-rich forests. In contrast, growth decreased and mortality increased as the climate warmed regardless of species diversity. Our results suggest that promoting high tree diversity may help reduce the climate and environmental change vulnerability of boreal forests

Data and R codes for Hisano et al. (2024): Functional diversity enhances dryland forest productivity under long-term climate change

Data and R codes for Hisano et al. (2024): Functional diversity enhances dryland forest productivity under long-term climate change.</p