Modelling effects of invasive species and drought on crayfish extinction risk and population dynamics     

Allyson N. Yarra  Daniel D. Magoulick 《水产资源保护:海洋与淡水生态系统》2019,29(1):1-11

Long‐term trends and drivers of larval phenology and abundance of dominant brachyuran crabs in the Gulf of St. Lawrence (Canada)     

Kim mond  Bernard Sainte‐Marie  Joël Bêty 《Fisheries Oceanography》2020,29(2):185-200

Climate change has led to major shifts in the timing of biological events, with many studies demonstrating earlier phenology in response to warming. However, few of these studies have investigated the effects of climate change on the phenology of larvae in marine species. Phenological shifts can result in mismatches between consumers and prey and hence affect growth and survival of individuals, and ultimately population demography. We investigated the temporal changes in phenology and abundance of the larvae of dominant brachyuran crabs in the southern Gulf of St. Lawrence (eastern Canada) based on plankton collections spanning 1982–2012. The Gulf of St. Lawrence has warmed since the early 1990s, and our analyses revealed that larvae of snow crab (Chionoecetes opilio) and toad crabs (Hyas spp.) exhibited a significant trend towards earlier phenology over the 30‐year study period. This shift in phenology appeared to be a consequence of the effect of climate warming on both the timing of hatching and larval development rate. Larval abundance responded differently by crab taxon to climate warming, likely due to differences in thermal tolerance. The warming trend was unfavourable to snow crab, which is the most cold‐adapted and stenothermic of the taxa examined in this study. The abundance of snow crab larvae was lower when sea ice retreat occurred earlier than day 110 of the year and sea surface temperature was higher than 8.5°C. On the other hand, larval abundance of rock crab (Cancer irroratus), which prefers higher temperatures, was positively related to surface temperature.  相似文献   

Integrated breeding approaches for improving drought and heat adaptation in chickpea (Cicer arietinum L.)     

Pooran M. Gaur  Srinivasan Samineni  Mahendar Thudi  Shailesh Tripathi  Sobhan B. Sajja  Veera Jayalakshmi  Durdundappa M. Mannur  Adiveppa G. Vijayakumar  Nadigatla V. P. R. Ganga Rao  Chris Ojiewo  Asnake Fikre  Paul Kimurto  Robert O. Kileo  Nigusie Girma  Sushil K. Chaturvedi  Rajeev K. Varshney  Girish P. Dixit 《Plant Breeding》2019,138(4):389-400

Chickpea (Cicer arietinum L.) is a dry season food legume largely grown on residual soil moisture after the rainy season. The crop often experiences moisture stress towards end of the crop season (terminal drought). The crop may also face heat stress at the reproductive stage if sowing is delayed. The breeding approaches for improving adaptation to these stresses include the development of varieties with early maturity and enhanced abiotic stress tolerance. Several varieties with improved drought tolerance have been developed by selecting for grain yield under moisture stress conditions. Similarly, selection for pod set in the crop subjected to heat stress during reproductive stage has helped in the development of heat‐tolerant varieties. A genomic region, called QTL‐hotspot, controlling several drought tolerance‐related traits has been introgressed into several popular cultivars using marker‐assisted backcrossing (MABC), and introgression lines giving significantly higher yield than the popular cultivars have been identified. Multiparent advanced generation intercross (MAGIC) approach has been found promising in enhancing genetic recombination and developing lines with enhanced tolerance to terminal drought and heat stresses.  相似文献   

基于最大熵方法的未来气候变化下狼毒在中国潜在分布的预测     

王文婷  王淑璠  张炜 《植物保护学报》2019,46(1):136-141

为了解入侵杂草狼毒Stellera chamaejasme在当前(1970—2000年)和未来气候情景下的扩散动态,采用最近邻体距离法选取样本数据,采用相关性分析和主成分分析选择环境变量,应用最大熵方法建立生态位模型用来预测当前(1970—2000年)和未来(2050年和2070年)气候变化下狼毒的潜在分布区,并应用Matlab软件计算气候变化下狼毒地理分布重心、平均海拔和等级分布区范围的动态变化。结果表明,当前(1970—2000年)气候条件下狼毒种群的潜在分布区从西南到东北呈带状分布,适生区等级随纬度的增加逐渐降低;未来气候变化下狼毒的潜在分布区将向西南方向和高海拔地区扩散,平均海拔将增高638 m,高适生区面积增长尤为迅速,2050年的相对增长率达51%;高寒草地将成为未来狼毒扩散的主要区域,因此应进一步加强对该区狼毒的防控。  相似文献   

Budyko-Fu模型下气候季节性指标中水热变化时相差的选取研究     

常斐杨  刘文兆  周海香  宁婷婷 《干旱地区农业研究》2019,37(3):208-214

流域水热耦合过程研究中,Budyko理论近年来得到了广泛的应用,其中又以傅抱璞公式（Budyko-Fu）比较著名。本研究在Budyko-Fu模型下,对其控制性参数ω与3种气候季节性指标的关系分别进行了分析。3种气候季节性指标包括SI1—考虑年内月降水量距平特征,SI2—考虑用正弦曲线模拟降水量与潜在蒸散季节变化时各自的振幅差别特征,以及SAI—在SI2的基础上进一步考虑降水量与潜在蒸散季节变化的相位差别。文章探讨了SAI指标计算中降水量与潜在蒸散季节相位取值年际变化与否的影响,由此形成SAI1和SAI2两个指标;随后比较了不同气候季节性指标在径流变化模拟中的应用效果。结果表明,在流域尺度水热耦合年际过程分析中,若气候季节性指标采用SAI2,即同一流域水热变化时相差由多年平均状况确定,且年际间保持不变,则效果较好;由此季节性指标结合NDVI数据给出的参数ω半经验公式的决定系数（R²）达到了0.746。在此基础上应用Budyko-Fu公式,流域年径流量的模拟精度显著提高。  相似文献   

Voluntary immobility and existential security in a changing climate in the Pacific     

Carol Farbotko  Celia McMichael 《Asia Pacific viewpoint》2019,60(2):148-162

With the expectation of adverse climate change impacts, some (often majority) Indigenous populations of the Pacific are expressing a preference to remain on Indigenous lands for cultural and spiritual reasons. In some cases, Indigenous people express preparedness to die on traditional territory rather than relocate, representing a new type of agency and resistance to dispossession. This is a prominent politics of place of relevance to emerging debates and decision‐making around retreat and relocation. If climate change is experienced by populations as an existential threat to culture, identity and place‐based connections, voluntary immobility can be an important adaptation strategy that helps to strengthen cultural and spiritual resilience among those facing the prospect of a lost homeland. This paper argues that voluntary immobility decisions need ethically robust and culturally appropriate policies and practices, particularly when a site is deemed by external experts to be no longer fit for human settlement. National governments, civil society groups, international organisations and donors will need to: engage in culturally meaningful dialogue with communities about relocation and immobility; respect, protect and fulfil the rights of ‘immobile’ people and those on the move; and confirm that in situ adaptation options have been exhausted.  相似文献   

Climate change,migration and human rights in Bangladesh: Perspectives on governance     

Mostafa Mahmud Naser  Mohammad Shahidul Hasan Swapan  Reazul Ahsan  Tanzim Afroz  Sabrina Ahmed 《Asia Pacific viewpoint》2019,60(2):175-190

Bangladesh experiences some of the most severe impacts of climate change, with impacts already evident in the coastal regions. Recent data shows that around 32% of the coastal communities in Bangladesh are affected by climate‐induced hazards each year. In 2011, 64% among them were displaced locally and 27% were displaced to other locations in Bangladesh. It requires comprehensive and viable polices and planning to meet the challenges of managing a large number of displaced people. In this context, this paper reviews and investigates the effectiveness of current governance frameworks to address migration of affected communities. It argues that migration can be an effective way to cope with environmental shocks. Finally, it discusses policy imperatives for effective protection of people displaced by climate risks with a special reference to adopting a human rights‐based approach in law and policy making for climate‐induced migration.  相似文献   

Can climate change influence agricultural GTFP in arid and semi-arid regions of Northwest China?     

FENG Jian 《干旱区科学》2020,12(5):837-853

There are eight provinces and autonomous regions (Gansu Province, Ningxia Hui Autonomous Region, Xinjiang Uygur Autonomous Region, Inner Mongolia Autonomous Region, Tibet Autonomous Region, Qinghai Province, Shanxi Province, and Shaanxi Province) in Northwest China, most areas of which are located in arid and semi-arid regions (northwest of the 400 mm precipitation line), accounting for 58.74% of the country's land area and sustaining approximately 7.84×10⁶ people. Because of drought conditions and fragile ecology, these regions cannot develop agriculture at the expense of the environment. Given the challenges of global warming, the green total factor productivity (GTFP), taking CO₂ emissions as an undesirable output, is an effective index for measuring the sustainability of agricultural development. Agricultural GTFP can be influenced by both internal production factors (labor force, machinery, land, agricultural plastic film, diesel, pesticide, and fertilizer) and external climate factors (temperature, precipitation, and sunshine duration). In this study, we used the Super-slacks-based measure (Super-SBM) model to measure agricultural GTFP during the period 2000-2016 at the regional level. Our results show that the average agricultural GTFP of most provinces and autonomous regions in arid and semi-arid regions underwent a fluctuating increase during the study period (2000-2016), and the fluctuation was caused by the production factors (input and output factors). To improve agricultural GTFP, Shaanxi, Shanxi, and Gansu should reduce agricultural labor force input; Shaanxi, Inner Mongolia, Gansu, and Shanxi should decrease machinery input; Shaanxi, Inner Mongolia, Xinjiang, and Shanxi should reduce fertilizer input; Shaanxi, Xinjiang, Gansu, and Ningxia should reduce diesel input; Xinjiang and Gansu should decrease plastic film input; and Gansu, Shanxi, and Inner Mongolia should cut pesticide input. Desirable output agricultural earnings should be increased in Qinghai and Tibet, and undesirable output (CO₂ emissions) should be reduced in Inner Mongolia, Xinjiang, Gansu, and Shaanxi. Agricultural GTFP is influenced not only by internal production factors but also by external climate factors. To determine the influence of climate factors on GTFP in these provinces and autonomous regions, we used a Geographical Detector (Geodetector) model to analyze the influence of climate factors (temperature, precipitation, and sunshine duration) and identify the relationships between different climate factors and GTFP. We found that temperature played a significant role in the spatial heterogeneity of GTFP among provinces and autonomous regions in arid and semi-arid regions. For Xinjiang, Inner Mongolia, and Tibet, a suitable average annual temperature would be in the range of 7°C-9°C; for Gansu, Shanxi, and Ningxia, it would be 11°C-13°C; and for Shaanxi, it would be 15°C-17°C. Stable climatic conditions and more efficient production are prerequisites for the development of sustainable agriculture. Hence, in the agricultural production process, reducing the redundancy of input factors is the best way to reduce CO₂ emissions and to maintain temperatures, thereby improving the agricultural GTFP. The significance of this study is that it explores the impact of both internal production factors and external climatic factors on the development of sustainable agriculture in arid and semi-arid regions, identifying an effective way forward for the arid and semi-arid regions of Northwest China.  相似文献   

Climate change and the genetics of insecticide resistance     

Jian Pu  Zinan Wang  Henry Chung 《Pest management science》2020,76(3):846-852

Changes in global temperature and humidity as a result of climate change are producing rapid evolutionary changes in many animal species, including agricultural pests and disease vectors, leading to changes in allele frequencies of genes involved in thermotolerance and desiccation resistance. As some of these genes have pleiotropic effects on insecticide resistance, climate change is likely to affect insecticide resistance in the field. In this review, we discuss how the interactions between adaptation to climate change and resistance to insecticides can affect insecticide resistance in the field using examples in phytophagous and hematophagous pest insects, focusing on the effects of increased temperature and increased aridity. We then use detailed genetic and mechanistic studies in the model insect, Drosophila melanogaster, to explain the mechanisms underlying this phenomenon. We suggest that tradeoffs or facilitation between adaptation to climate change and resistance to insecticides can alter insecticide resistance allele frequencies in the field. The dynamics of these interactions will need to be considered when managing agricultural pests and disease vectors in a changing climate. © 2019 Society of Chemical Industry  相似文献   

气候变化背景下埃及吹绵蚧在中国的适生区预测   总被引：1，自引：0，他引：1  

刘洋  石娟 《植物保护》2020,46(1):108-117

基于埃及吹绵蚧分布点的经纬度数据,利用最大熵模型MaxEnt软件对埃及吹绵蚧在中国当前和未来(2050年和2070年)的适生区进行了预测,为林业和海关检疫部门对埃及吹绵蚧当前与未来的防控与检疫工作提供重要参考依据。在本研究中,梳理并筛选了埃及吹绵蚧在国内外的分布点,通过优化MaxEnt生态位模型,预测了在当前气候和未来气候下埃及吹绵蚧在中国的潜在分布,通过统计软件计算了各种气候条件下的适生区面积,并对影响埃及吹绵蚧分布的环境因子进行了筛选和统计。预测结果显示,基于当前气候,埃及吹绵蚧在我国的潜在分布区包括华南全部地区、华中和西南部分地区,主要集中在我国经度98°E～123°E、纬度20°N～30°N的地区。未来气候条件下的适生区范围呈现增大的趋势;刀切法(Jackknife)显示,对埃及吹绵蚧分布影响较大的环境要素主要为降水量,同时模型计算了埃及吹绵蚧定殖所需的四项环境要素的适宜范围。结合实际踏查数据和文献资料,MaxEnt模型预测结果可信度高,精确预测了影响埃及吹绵蚧分布的环境因子及其适生区范围,对埃及吹绵蚧的研究具有重要意义。  相似文献