Historical Small‐Scale Surface Structures as a Model for Post‐Mining Land Reclamation

Historical land use provides long‐term field experiments that give valuable clues for ecosystem management and habitat restoration. We hypothesized that remnants of a small‐scale charcoal‐ore industry that ceased more than a century ago still affect soil properties and the litter‐dwelling fauna of a beech forest on rendzina soil (pH 4–6.5). We sampled the remains of charcoal kilns, small mining pits, and mounds of dugout material. Soils from kilns displayed increased carbon and nutrient contents and soils from kilns and in pits tended to be moister than that from all other locations. Leaf litter accumulated in the pits. Most mesofauna taxa occurred independent of the modifications, whereas larger‐sized Collembola and many macrofauna taxa (Aranea, Chilopoda, Diplopoda, Isopoda, Coleoptera, and Gastropoda) were more abundant in the pits. Snails are highly sensitive to microclimatic fluctuations and structural changes and thus were used to compare man‐made structures with natural ones: assemblages from kilns equaled those from the unmodified forest floor, assemblages from pits resembled those from adjacent to coarse woody debris (CWD), and assemblages from mounds resembled those from outcrops and tree bases. The outcrops were the local keystone structure, but mining pits and CWD added to species richness as they provided shelter for hygrophilous species. We thus recommend maintaining or creating a diversified soil surface structure in post‐mining land reclamation to accumulate organic matter and nutrients and to buffer microclimatic extremes.     

基于夏季小气候效应的杭州街道适应性设计策略研究

随着城市热岛效应日趋严重,小尺度公共空间的气候研究已成为风景园林学科的研究热点之一。选取杭州市文一西路和古墩路作为实测对象,于2017年8月对各测点空间的空气温度、相对空气湿度、太阳辐射强度、风速风向进行测定,分析小气候因子日变化趋势,并运用Rayman 1.2模型评价人体舒适度,针对性提出街道空间小气候适应性设计策略。研究表明,尽可能设定与城市主导风平行或接近的街道朝向,通过人为增建遮阴空间、调控街道界面小气候一致、采用植物或绿色建筑材料、增设道路中央景观界面,且当人行道及机非分隔绿带分别种植落叶、常绿乔木,设五条绿带,选用乔—灌—草复层结构,同时增设垂直绿化时,能够有效缓解夏季极端热感受,从而营建舒适健康的城市街道空间。     

Habitat selection by a threatened desert amphibian

Habitat degradation and fragmentation are major drivers of amphibian declines. The loss of environmental features that allow for movement between water sources may be particularly detrimental for amphibians in arid environments. Climate changes will increase the importance of microhabitats to amphibians. Enhancing areas to facilitate movement may be a necessary conservation strategy for many animal species that depend on wetlands, including federally threatened Chiricahua leopard frogs (Lithobates chiricahuensis). Habitat preferences of this frog species are not well understood. We sought to better understand fine‐scale habitat selection, to inform conservation of Chiricahua leopard frogs. We conducted our study on the Ladder Ranch, a privately owned working bison ranch in New Mexico, USA that supports a large proportion of the remaining Chiricahua leopard frogs in the state. We attached radio transmitters to 44 frogs during summer 2014. We located each frog daily for up to 8 weeks (median = 30 days). We assessed fine‐scale habitat selection by comparing characteristics at each frog location and a random location 5 m away using conditional logistic regression. Frogs preferred features that likely reduce desiccation, even after accounting for the presence of water. Frogs selected areas with more low‐lying cover, especially aquatic vegetation and woody debris, a tree overstory, and a mud substrate. We recommend managing potential movement corridors for Chiricahua leopard frogs by ensuring the presence of muddy creek bottoms, woody debris, riparian overstory, low‐lying ground cover, and pools. Microclimates created by these features seem especially valuable given warming temperatures and modified precipitation regimes, resulting in decreased surface water, soil moisture, and vegetation cover. Retaining or creating preferred habitat features and microclimates in areas between water sources may increase connectivity among isolated populations of Chiricahua leopard frogs and could improve persistence and recovery of other water‐obligate species in arid landscapes.     

Body size and activity times mediate mammalian responses to climate change

Model predictions of extinction risks from anthropogenic climate change are dire, but still overly simplistic. To reliably predict at‐risk species we need to know which species are currently responding, which are not, and what traits are mediating the responses. For mammals, we have yet to identify overarching physiological, behavioral, or biogeographic traits determining species' responses to climate change, but they must exist. To date, 73 mammal species in North America and eight additional species worldwide have been assessed for responses to climate change, including local extirpations, range contractions and shifts, decreased abundance, phenological shifts, morphological or genetic changes. Only 52% of those species have responded as expected, 7% responded opposite to expectations, and the remaining 41% have not responded. Which mammals are and are not responding to climate change is mediated predominantly by body size and activity times (phylogenetic multivariate logistic regressions, P < 0.0001). Large mammals respond more, for example, an elk is 27 times more likely to respond to climate change than a shrew. Obligate diurnal and nocturnal mammals are more than twice as likely to respond as mammals with flexible activity times (P < 0.0001). Among the other traits examined, species with higher latitudinal and elevational ranges were more likely to respond to climate change in some analyses, whereas hibernation, heterothermy, burrowing, nesting, and study location did not influence responses. These results indicate that some mammal species can behaviorally escape climate change whereas others cannot, analogous to paleontology's climate sheltering hypothesis. Including body size and activity flexibility traits into future extinction risk forecasts should substantially improve their predictive utility for conservation and management.     

Wind farm and solar park effects on plant–soil carbon cycling: uncertain impacts of changes in ground‐level microclimate

Global energy demand is increasing as greenhouse gas driven climate change progresses, making renewable energy sources critical to future sustainable power provision. Land‐based wind and solar electricity generation technologies are rapidly expanding, yet our understanding of their operational effects on biological carbon cycling in hosting ecosystems is limited. Wind turbines and photovoltaic panels can significantly change local ground‐level climate by a magnitude that could affect the fundamental plant–soil processes that govern carbon dynamics. We believe that understanding the possible effects of changes in ground‐level microclimates on these phenomena is crucial to reducing uncertainty of the true renewable energy carbon cost and to maximize beneficial effects. In this Opinions article, we examine the potential for the microclimatic effects of these land‐based renewable energy sources to alter plant–soil carbon cycling, hypothesize likely effects and identify critical knowledge gaps for future carbon research.     

水库生态系统调节小气候及净化空气细菌的服务功能——以深圳梅林水库和西丽水库为例

生态系统服务功能已成为生态学研究的热点,但水库生态系统服务功能的研究较少.对深圳市梅林水库和西丽水库调节小气候和净化空气细菌的服务功能进行了实地研究,并对调节小气候的服务功能进行了价值评估.结果表明水库生态系统有一定的降温、增湿和净化空气细菌效应.在炎热的夏季,梅林水库和西丽水库的平均温度和最高温度比市区分别降低1.59、2.35℃和2.56、4.10℃.在干燥的冬季,梅林水库和西丽水库相对湿度的平均值和最大值较市区分别提高了6.01%、11.10%和7.38%、7.80%.梅林水库、西丽水库和市区空气细菌数量分别为9、10cfu/皿· 5min和107cfu/皿· 5min,库区空气细菌数量远远少于市区.梅林水库和西丽水库调节小气候的服务价值分别为1249.13×104元· a-1和5441.83×104元· a-1.     

开放式空气CO2浓度增高对水稻冠层微气候的影响

利用位于江苏省无锡市安镇的我国唯一的农田开放式空气CO2 浓度增高 (FACE)系统平台 ,于2 0 0 1年 8月 2 6日至 10月 13日 (水稻抽穗至成熟期 )进行水稻作物冠层微气候连续观测 ,以研究FACE对水稻冠层微气候特征的影响 .结果表明 ,FACE降低了水稻叶片的气孔导度 ,FACE与对照水稻叶片气孔导度的差异上层叶片大于下层叶片 ,生长前期大于生长后期 .FACE使白天水稻冠层和叶片温度升高 ,这种差异生长前期大于生长后期 ;但FACE对夜间水稻冠层温度的影响不明显 .在水稻旺盛生长的抽穗开花期 ,晴天正午前后FACE水稻冠层温度比对照高 1.2℃ ;从开花至成熟期 ,FACE水稻冠层白天平均温度比对照高 0 .4 3℃ .FACE对冠层空气温度也有影响 ,白天水稻冠层空气温度FACE高于对照 ,这种差异随太阳辐射增强而增大且冠层中部大于冠层顶部 ;冠层中部空气温度FACE与对照的差异 (Tface-Tambient)日最大值在 0 .4 7～ 1.2℃之间 ,而冠层顶部的Tface-Tambient日最大值在 0 .37～ 0 .8℃之间 .夜间水稻冠层空气温度FACE与对照差别不大 ,变化在± 0 .3℃之内 .而FACE对水稻冠层空气湿度无显著影响 ,表明FACE使水稻叶片气孔导度降低 ,从而削弱了植株的蒸腾降温作用 ,导致水稻冠层温度和冠层空气温度升高 ,改变了整个水稻冠层的温度环     

热带山地雨林CO2浓度环境的时空梯度特征

基于2000年旱、雨季梯度观测结果叠加分析晴及晴间少云天气,山地雨林垂直CO2浓度雨季在333～350ml/m3的时间空间特征显著即800～1800林内1 6m至冠顶28m,较旱季浓度分别小10～21、7～20.2ml/n3,夜间呼吸影响空间的最大浓度均在近林地上5m、出现时段有季节性差别.800～1800林冠上CO 2浓度梯度、气温梯度表明,大气至林冠的CO2通量和冠层指向大气的热通量特征显著,夜间则梯度值减小、方向相反,且雨季晴天的△Ct/△Z大于旱季,旱季气温梯度大于雨季;林内二氧化碳垂直梯度(△Ct/△Z＜0)昼夜均小于零,即林地指向上层的CO2通量特征显著,且两类天气均表现出雨季的浓度梯度大于相应的旱季.从而,科学地揭示出在28m的山地雨林垂直高度上,植物光合固定CO2最多而导致空间浓度最低的季节、天气、时间和空间,同时证实冠上两个高度实时气温与相应CO2浓度成CCO2.=a10b/T.而山地雨林水汽压时空则较为直观地解释了蒸发、扩散和乱流机制影响的效果以及雨林"雨"形成的特征.     

Monitoring the dynamics of orchard colonisation by Anthonomus pomorum in spring

Overwintered adult apple blossom weevils, Anthonomus pomorum (L.) (Coleoptera: Curculionidae), colonise apple trees, Malus domestica Borkh. (Rosaceae), in early spring. Information gained from a suitable monitoring technique could serve as a guide to determining the accurate timing for control measures. To assess tree colonisation by flight and crawling, Plexiglas flight traps and commercial screen traps developed for different curculionid species were used. Refuges were mimicked by a newly designed shelter trap based on transparent bubble wrap. The trap catches were contrasted to the limb jarring technique. Microclimate and weather conditions were determined over a trial period of one and a half months. The shelter traps caught a high number of weevils irrespective of weather conditions, and thus performed better than both flight and screen traps. The temperature level within the shelter traps was slightly, but significantly, higher than on the trunk, indicating that weevils exploit microclimatic differences and occupy thermally favourable refuges. The seasonal culmination of colonisation as determined by shelter traps coincided with that as determined by the two methods used to monitor weevil movement towards host trees (flight traps and screen traps). The data indicated that not only flight, but also crawling as quantified by the screen traps contributes substantially to spring colonisation. Captures by all three types of traps over the spring season were significantly positively correlated with each other, but in most respects not with the results of the limb jarring. We conclude that the newly designed shelter trap will be useful for accurately monitoring the seasonal course of colonisation and holds promise for determining the timing of interventions.