Potential distributions of seven sympatric sclerophyllous oak species in Southwest China depend on climatic, non-climatic, and independent spatial drivers

Key message An ensemble modelling approach was performed to predict the distributions of seven sympatric sclerophyllous oak species in the Hengduan Mountains of Southwest China. Spatial eigenvector filters revealed missing factors in addition to commonly used environmental variables, thus effectively improved predictive accuracy for the montane oak species. This study identified a richness center of sclerophyllous oaks, which provides a reference for proper conservation and utilization of oak resources. Context As key species and important trees for construction- and fuel-wood, montane sclerophyllous oaks (Quercus sect. Heterobalanus) in the Hengduan Mountains of Southwest China are threatened by climate change, habitat fragmentation, and human activities. Aims This study aims to simulate the potential distributions of seven sympatric sclerophyllous oak species with an emphasis on exploring the relative importance of climatic, non-climatic, and additional spatial factors. Methods We performed an ensemble modelling approach of six ecological niche models in combination with spatial eigenvector filters to predict the potential distributions of seven oak species. Results The results elucidated that temperature seasonality, followed by land use/cover and the human influence index were the most critical variables controlling oak species distributions. Regardless of the selected algorithm, the best performing models for most oaks combined climatic and non-climatic factors as well as additional spatial filters. Conclusion It is necessary to strengthen the conservation of oak species at the junction of Sichuan and Yunnan Province where we found the richness center of the studied oaks. Our research provides essential insights for the rational conservation and management of sclerophyllous oak species, suggesting that spatial constraints might reflect limited ability of migration under future climate change.Peer reviewe

Phosphorous application improves drought tolerance of phoebe zhennan

Phoebe zhennan (Gold Phoebe) is a threatened tree species in China and a valuable and important source of wood and bioactive compounds used in medicine. Apart from anthropogenic disturbances, several biotic constraints currently restrict its growth and development. However, little attention has been given to building adaptive strategies for its conservation by examining its morphological and physio-biochemical responses to drought stress, and the role of fertilizers on these responses. A randomized experimental design was used to investigate the effects of two levels of irrigation (well-watered and drought-stressed) and phosphorous (P) fertilization treatment (with and without P) to assess the morphological and physio-biochemical responses of P. zhennan seedlings to drought stress. In addition, we evaluated whether P application could mitigate the negative impacts of drought on plant growth and metabolism. Drought stress had a significant negative effect on the growth and metabolic processes of P. zhennan. Despite this, reduced leaf area, limited stomatal conductance, reduced transpiration rate, increased water use efficiency, enhanced antioxidant enzymes activities, and osmolytes accumulation suggested that the species has good adaptive strategies for tolerating drought stress. Application of P had a significant positive effect on root biomass, signifying its improved water extracting capacity from the soil. Moreover, P fertilization significantly increased leaf relative water content, net photosynthetic rate, and maximal quantum efficiency of PSII under drought stress conditions. This may be attributable to several factors, such as enhanced root biomass, decreased malondialdehyde content, and the up-regulation of chloroplast pigments, osmolytes, and nitrogenous compounds. However, P application had only a slight or negligible effect on the growth and metabolism of well-watered plants. In conclusion, P. zhennan has a strong capability for drought resistance, while P application facilitates and improves drought tolerance mostly through physio-biochemical adjustments, regardless of water availability. It is imperative to explore the underlying metabolic mechanisms and effects of different levels of P fertilization on P. zhennan under drought conditions in order to design appropriate conservation and management strategies for this species, which is at risk of extinction.Fil: Tariq, Akash. Chinese Academy of Sciences; República de ChinaFil: Pan, Kaiwen. Chinese Academy of Sciences; República de ChinaFil: Olatunji, Olusanya A.. Chinese Academy of Sciences; República de ChinaFil: Graciano, Corina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; ArgentinaFil: Li, Zilong. Chinese Academy of Sciences; República de ChinaFil: Sun, Feng. Chinese Academy of Sciences; República de ChinaFil: Sun, Xiaoming. Chinese Academy of Sciences; República de ChinaFil: Song, Dagang. Chinese Academy of Sciences; República de ChinaFil: Chen, Wenkai. Chinese Academy of Sciences; República de ChinaFil: Zhang, Aiping. Chinese Academy of Sciences; República de ChinaFil: Wu, Xiaogang. Chinese Academy of Sciences; República de ChinaFil: Zhang, Lin. Chinese Academy of Sciences; República de ChinaFil: Mingrui, Deng. Chinese Academy of Sciences; República de ChinaFil: Xiong, Qinli. Chinese Academy of Sciences; República de ChinaFil: Liu, Chenggang. Chinese Academy of Sciences; República de Chin

What Is Left for Our Next Generation? Integrating Ecosystem Services into Regional Policy Planning in the Three Gorges Reservoir Area of China

Land use/Land cover (LULC) changes as a result of policy planning influence ecosystem structures, processes, and functions, which are the basis for providing a wide range of ecosystem services (ES). There is an increasing consensus about the importance of integrating ES into ecological policy but quantifying the potential impacts of different policy on ES has proven difficult. We designed a remote sensing, geographic information system and scenario analysis-based approach to estimate and analyze the relationship between ES (soil conservation and carbon sequestration) and ecological policy designed to improve human welfare in the Chongqing municipality in the upper reaches of the Three Gorges Reservoir Area, China; a densely populated, highly modified watershed with serious soil erosion and flood hazard. Three alternative scenarios in 2050 were modeled for the Three Gorges Reservoir Area watershed. The model GEOMOD was used to predict future LULC changes due to policy planning. The ES models (Universal Soil Loss Equation model and Carnegie-Ames-Stanford Approach model) were designed to inform decisions, with an aim to align economic forces with conservation. We examine policy effectiveness by comparing scenarios for 2050 (Scenario1: Maintain current policy with no considerations of ES; Scenario2: Integrate ES into policy planning; Scenario3: Integrate ES into policy planning in view of the need of local people). Scenario-based LULC change analysis revealed that if the current afforestation policy continues (scenario 1), total ES would be further increased in 2050 due to expansion of forest cover. However, by targeting policy to improve ES provision (scenarios 2 and 3), ecological risks of soil loss can be significantly reduced and carbon sequestration enhanced. Scenario 3, thus, provided the best future environmental development scenario considering the need of local people in each region for ES. This scenario will theoretically help the Three Gorges Dam to harvest more ecological benefits through improvements in soil conservation and carbon sequestration. This study highlights the observation that including ES in policy planning and has a great potential to generate opportunities to maximize ES. This study highlights that including ES in policy planning has a great potential to generate opportunities to maximize ES. Hence, there is a need to encourage proper implementation of ecological policy to maintain and improve ES

Potential risk to water resources under eco-restoration policy and global change in the Tibetan Plateau

Water shortage is a core problem that has hindered sustainable development worldwide. The Tibetan Plateau feeds ten main rivers on which almost 20% of the world’s population depends. However, the plateau has suffered serious environmental deterioration from global warming. Since the 1980s, the Chinese government has supported ecological restoration in the Tibetan Plateau, mainly by promoting large-scale afforestation and grassland conservation. To identify the impact of global change and ecological restoration policy on the plateau, we used geographic information system (GIS) methodologies to study changes to the water supplies in the region as a result of implemented restoration programs. Moreover, we also used GIS to assess the potential risks of these changes for the long-term sustainability of water supplies. Our findings show that the quantity of water supplies in the Tibetan Plateau has increased over the last 36 years; this was attributed to an increase in precipitation as well as increasing glacial meltwater due to global warming. We also found that the water consumption associated with afforestation projects reduced the water yield, in that it was altered by the artificial establishment of plant communities, with different afforestation projects variously impacting water consumption. The potential risk areas in the plateau were mainly distributed in areas with dense human populations and villages, and intensive human activities around forest shrubs where ecological restoration programs had been largely implemented. We highlight the need for ecosystem management and monitoring within larger afforestation programs, which should include the planting of vegetation with low rates of water consumption

Adsorptive Removal of Toxic Chromium from Waste-Water Using Wheat Straw and Eupatorium adenophorum.

Environmental pollution with heavy metals is a serious issue worldwide posing threats to humans, animals and plants and to the stability of overall ecosystem. Chromium (Cr) is one of most hazardous heavy metals with a high carcinogenic and recalcitrant nature. Aim of the present study was to select low-cost biosorbent using wheat straw and Eupatorium adenophorum through simple carbonization process, capable of removing Cr (VI) efficiently from wastewater. From studied plants a low cost adsorbent was prepared for removing Cr (VI) from aqueous solution following very simple carbonization method excluding activation process. Several factors such as pH, contact time, sorbent dosage and temperature were investigated for attaining ideal condition. For analysis of adsorption equilibrium isotherm data, Langmuir, Freundlich and Temkin models were used while pseudo-first-order, pseudo-second-order, external diffusion and intra-particle diffusion models were used for the analysis of kinetic data. The obtained results revealed that 99.9% of Cr (VI) removal was observed in the solution with a pH of 1.0. Among all the tested models Langmuir model fitted more closely according to the data obtained. Increase in adsorption capacity was observed with increasing temperature revealing endothermic nature of Cr (VI). The maximum Cr (VI) adsorption potential of E. adenophorum and wheat straw was 89.22 mg per 1 gram adsorbent at 308K. Kinetic data of absorption precisely followed pseudo-second-order model. Present study revealed highest potential of E. adenophorum and wheat straw for producing low cost adsorbent and to remove Cr (VI) from contaminated water

Combined effects of cropping types and simulated extreme precipitation on the community composition and diversity of soil macrofauna in the eastern Qinghai-Tibet Plateau

PurposeExtreme precipitation as global change greatly affects above- and below-ground biodiversity. Soil macrofauna play a key role in the agroforestry ecosystem processes. Extreme precipitation might negatively impact soil macrofauna by changing soil water content. Particularly, whether cropping types are beneficial to alleviate response of soil macrofauna to extreme precipitation remains unexplored.Materials and methodsEffects of simulated extreme precipitation of 1month on soil macrofauna were studied under Chinese prickly ash (Zanthoxylum bungeanum) intercropped with soybean (Glycine max), Chinese prickly ash intercropped with sweet pepper (Capsicum annuum), and Chinese prickly ash monoculture. Soil macrofauna and soil samples were collected in three soil depths (0-10, 10-20, and 20-30cm) per plot. The abundance, diversity, and vertical distribution of soil macrofauna were analyzed for each sample at genus and trophic level. Each sieved soil sample was analyzed for soil water content, soil nitrate nitrogen (NO3--N), ammonium nitrogen (NH4+-N) and organic matter. Descriptive statistics and significance tests on raw data were carried out using the SPSS 16.0 software at P<0.05.Results and discussionA total of 502 soil macrofauna individuals were observed, and belonged to 14 genera, and consisted mainly of earthworms, arthropods. The richness, density, and biomass, as well as vertical distribution of total soil macrofauna were unaffected by extreme precipitation. Only Eisenia density and biomass were significantly decreased by extreme precipitation. The plots intercropped with soybean had higher density, biomass, and richness than the plots intercropped with sweet pepper and prickly ash monoculture. Cropping types significantly influenced density of total soil macrofauna under control condition but not extreme precipitation treatment. The abundance of total soil macrofauna was significantly and positively related to soil NH4+-N, total soil inorganic N, and soil organic matter.ConclusionsOur results suggest that the impacts of cropping types rather than extreme precipitation on soil macrofauna abundance, diversity, and vertical distribution are significant. However, extreme precipitation changes the response of soil macrofauna to cropping types