An assessment of the impact of climate adaptation measures to reduce flood risk on ecosystem services

Measures of climate change adaptation often involve modification of land use and land use planning practices. Such changes in land use affect the provision of various ecosystem goods and services. Therefore, it is likely that adaptation measures may result in synergies and trade-offs between a range of ecosystems goods and services. An integrative land use modelling approach is presented to assess such impacts for the European Union. A reference scenario accounts for current trends in global drivers and includes a number of important policy developments that correspond to on-going changes in European policies. The reference scenario is compared to a policy scenario in which a range of measures is implemented to regulate flood risk and protect soils under conditions of climate change. The impacts of the simulated land use dynamics are assessed for four key indicators of ecosystem service provision: flood risk, carbon sequestration, habitat connectivity and biodiversity. The results indicate a large spatial variation in the consequences of the adaptation measures on the provisioning of ecosystem services. Synergies are frequently observed at the location of the measures itself, whereas trade-offs are found at other locations. Reducing land use intensity in specific parts of the catchment may lead to increased pressure in other regions, resulting in trade-offs. Consequently, when aggregating the results to larger spatial scales the positive and negative impacts may be off-set, indicating the need for detailed spatial assessments. The modelled results indicate that for a careful planning and evaluation of adaptation measures it is needed to consider the trade-offs accounting for the negative effects of a measure at locations distant from the actual measure. Integrated land use modelling can help land use planning in such complex trade-off evaluation by providing evidence on synergies and trade-offs between ecosystem services, different policy fields and societal demands.     

Scenarios of long-term farm structural change for application in climate change impact assessment

Towards 2050, climate change is one of the possible drivers that will change the farming landscape, but market, policy and technological development may be at least equally important. In the last decade, many studies assessed impacts of climate change and specific adaptation strategies. However, adaptation to climate change must be considered in the context of other driving forces that will cause farms of the future to look differently from today’s farms. In this paper we use a historical analysis of the influence of different drivers on farm structure, complemented with literature and stakeholder consultations, to assess future structural change of farms in a region under different plausible futures. As climate change is one of the drivers considered, this study thus puts climate change impact and adaptation into the context of other drivers. The province of Flevoland in the north of The Netherlands was used as case study, with arable farming as the main activity. To account for the heterogeneity of farms and to indicate possible directions of farm structural change, a farm typology was developed. Trends in past developments in farm types were analyzed with data from the Dutch agricultural census. The historical analysis allowed to detect the relative importance of driving forces that contributed to farm structural changes. Simultaneously, scenario assumptions about changes in these driving forces elaborated at global and European levels, were downscaled for Flevoland, to regional and farm type level in order to project impacts of drivers on farm structural change towards 2050. Input from stakeholders was also used to detail the downscaled scenarios and to derive historical and future relationships between drivers and farm structural change. These downscaled scenarios and future driver-farm structural change relationships were used to derive quantitative estimations of farm structural change at regional and farm type level in Flevoland. In addition, stakeholder input was used to also derive images of future farms in Flevoland. The estimated farm structural changes differed substantially between the two scenarios. Our estimations of farm structural change provide a proper context for assessing impacts of and adaptation to climate change in 2050 at crop and farm level.     

杉木花粉和花粉管中的微管分布

通过间接免疫荧光标记对杉木花粉和花粉管内微管骨架的分布进行观察,结果显示:杉木花粉在萌发初期的花粉中存在浓密的微管网络,主要呈现横向或斜向分布;花粉萌发后,微管开始从花粉粒延伸入花粉管中,花粉粒和花粉管基部微管排列呈现横向、斜向或螺旋状排列;在杉木花粉管中部微管骨架则主要呈现与花粉管伸长相平行的网络状分布,在部分伸长初期的花粉管中微管会延伸到花粉管顶端.在多数花粉及花粉管中微管主要分布在细胞的周质.在花粉管顶端微管分布有3种形式:1)在花粉管亚顶端有垂直于花粉管伸长方向排列的微管;2)花粉管中微管呈螺旋状分布并延伸到顶端;3)微管在花粉管顶端形成复杂的网络结构.     

Weeds,aphids, and specialist parasitoids and predators benefit differently from organic and conventional cropping of winter cereals

The aphid–natural enemy interaction in winter wheat fields constitutes a complex system that has been frequently studied because of its implication for biological control. However, not all of the aphids living in cereal fields are crop pests, as there are also aphids living on weeds that may serve as alternative hosts or prey for aphid parasitoids or predators. In this context, a concomitant survey of the plant and insect communities was conducted to understand how different plant communities affect the abundance and richness of aphids and the interactions with their natural enemies. The plant community was split into functional groups (grasses, legumes and forbs), and the aphid community was divided into feeding groups according to their host preferences (specialists in grasses or forbs). The grass aphids, which dominated the total aphid catches, responded positively to grass cover, which was particularly enhanced in the conventional fields. Conversely, the forb aphids, which mainly conditioned the total species richness of the aphids, were closely correlated with the local abundance of legumes. The system of cereal aphid-parasitoids was enhanced in the conventional fields, where the abundance of grasses was higher, whereas the legumes of the organic fields indirectly played a key role in enhancing the richness of the parasitoids and the abundance of predators. Our findings indicate that a bottom-up effect exists throughout the plant community, aphids, and aphidophagous insects and that plant community characteristics should be considered to better understand cereal aphid control.     

日本乙誓脑炎病毒NS1基因及其疫苗的研究进展

日本乙型脑炎是由日本乙型脑炎病毒引起的严重的人畜共患传染病。乙型脑炎病毒的三种糖基化蛋白PrM、E和NS1是其主要免疫保护性抗原,其中PrM和E蛋白是日本乙型脑炎病毒的结构蛋白,其结构和相关疫苗研究的报道较多。NS1蛋白是日本乙型脑炎病毒的非结构蛋白,其主要参与病毒复制的早期阶段,推测可能参与病毒组装和释放。可诱导补体依赖性溶细胞反应,不能产生中和抗体,能诱发机体在非中和性抗体存在的情况下产生保护性免疫。在接种乙脑病毒的细胞的细胞内、细胞表面及上清液中均含有大量的NS1蛋白。对小鼠接种NS1蛋白或NS1蛋白特异性抗体,均能让小鼠产生对乙脑病毒感染的保护性免疫作用。本文主要就乙型脑炎病毒非结构基因NS1及其免疫疫苗的研究进展进行综述,为其更进一步深入研究IEV NS1基因及其相关疫苗奠定基础。     

长潭省级自然保护区三种森林类型林地水分贮蓄能力分析

文章以广东省长潭省级自然保护区中常绿阔叶林、杉木林和马尾松林为研究对象,通过测量1 m厚土壤层的5种土壤水分贮蓄指标,比较了三种林型的土壤贮蓄水分能力。结果表明,三种森林生态系统林地土壤1 m厚土层各持水量指标间差异不显著,且同一类型森林样点环境条件差异所造成的影响大于森林类型对林地土壤1 m厚土层水文性质的影响。     

Selection on Growth and Cold Tolerance in 11 Eucalyptus Seedlots

对桉属7个种11个种批进行生长和耐冻性的联合选择研究.选出在冷凉地区较有潜力的邓恩桉17913、20665和17922以及本沁桉18788共4个种批,蓄积量14.80 ～20.93 m3/a·hm2,这为国内冷凉地区发展短轮伐期桉树用材林提供了可供选择的速生、耐冻的种植材料.另外,多雷苷桉虽然生长中等(蓄积量10.03 m3/a·hm2),但耐冻性好,可以作为进一步选择和杂交育种的备用材料.     

Effects of single-tree selection harvesting on hymenopteran and saproxylic insect assemblages in the canopy and understory of northern temperate forests

Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system used to emulate local small-scale natural disturbance and maintain uneven-aged forest structure in temperate forests. Here, we test for differences in richness, abundance, and composition of hymenopteran and saproxylic insect assemblages at four different taxon levels (selected insect orders; and all hymenopteran families, and braconid subfamilies and morphospecies) between the canopy and understory of unharvested and single-tree selection harvested sites in a northern temperate forest from central Canada. Harvesting had no effect on insect assemblage richness, composition or abundance at the three highest taxon levels (order, family and subfamily). Similarly, richness and abundance at the lowest-taxon level (braconid morphospecies) were similar, although composition differed slightly between unharvested and harvested stands. Insect assemblages were vertically stratified, with generally higher abundance (for Diptera, Hymenoptera, some hymenopteran families and braconid subfamilies) and richness (for braconid morphospecies) in the understory than the canopy. In particular, composition of the braconid morphospecies assemblage showed relatively low similarity between the understory and canopy. Single-tree selection harvesting appears to influ-ence wood-associated insect taxa only subtly through small changes in community composition at the lowest taxon level, and thus is recommended as a conservative approach for managing these northern temperate forests.     

Diameter and death of whorl and interwhorl branches in Atlas cedar (<Emphasis Type="Italic">Cedrus atlantica</Emphasis> Manetti): a model accounting for acrotony

• Introduction   

Branch size and branch status (dead or alive) are important characteristics closely related to tree growth and wood quality. The aim of this study was to design models for the diameter and status of branches in Atlas cedar (Cedrus atlantica Manetti).     

Modeling of light transmission under heterogeneous forest canopy: an appraisal of the effect of the precision level of crown description

• Context  

Light availability in forest understory is essential for many processes; it is, therefore, a valuable information regarding forest management. However, its estimation is often difficult and direct measurements are tedious. Models can be used to compute understory light, but they often require a lot of field data to accurately predict light distribution, particularly in the case of heterogeneous canopies.