基于遥感数据的大尺度区域水田空间格局及生态服务价值变化分析

受经济和气候驱动，长江经济带水田空间格局发生了显著变化，影响区域粮食安全与生态安全。本研究基于1990-2015年土地利用遥感监测数据，利用GIS的空间分析功能，探究长江经济带水田空间格局动态变化特征，采用当量因子法计算生态系统服务价值（ESV），分析了水田变化的综合影响。结果表明：1）1990-2015年长江经济带水田规模持续缩减，共减少了17390km²，减幅呈增长态势具有显著地域差异，长江中上游与下游的水田减幅相差约为9.56%。其中下游减幅较大，水田占区域比例随之降低，中上游恰好相反。2）由于经济建设及水产养殖的发展，水田主要转化为建设用地和水系，水田主要由水系、旱地和湿地等转化而来。长江三角洲城市群、长江中游及成渝城市群的水田变化最为剧烈，建设用地侵占水田扩张的现象分布广泛，水田转为水系主要在两湖平原局部地区。3）水田与其他生态系统的转化对ESV是正影响，水田转为水系对此贡献最大，其转化规模决定了不同时期ESV净增量的大小，水系转化为水田损失的价值最多，建设用地侵占水田次之。不同市域的水田变化情况不一致，因此ESV增减情况具有明显差异。4）生态系统服务中水文调节、水资源供给增强的同时，食物生产、气体调节受到严重损害，与水资源规模扩大和水田资源大量流失有直接关系。研究结果有助于揭示长江流域水田的时空变化过程及其对各项生态系统服务的影响，可为区域土地利用规划、农业政策与生态可持续发展提供理论支持。     

Exploring the Role of Management in the Coproduction of Ecosystem Services from Spanish Wooded Rangelands

The wood pastures or hardwood rangelands of the southwestern Iberian Peninsula are complex social-ecological systems created from the long-term interaction of society and the landscape. Dehesa, oak woodlands managed for grazing, cropping, and other forms of production, is the most common rangeland system and one of the most distinctive landscapes. Traditionally characterized by multifunctional low-intensity management that enhances a wide range of ecosystem services, current management has shifted from the traditional toward more intensified models. This paper assesses the coproduction of ecosystem services on dehesa properties by exploring the relationship between biophysical and sociocultural factors and dehesa management practices. Based on 42 surveys we analyze 16 quantitative indicators using multivariate techniques. The results indicate that there are four main dehesa types as defined by their characteristics and management: large heterogeneous operations with diverse products; small and homogeneous operations focused on a reduced number of products; medium-large properties focused on crop production; and midsized properties with easy public access. Management is the result of the dynamics of interacting biophysical and sociocultural factors that influence manager priorities and investments. Management decisions group around the degree of multifunctionality of the operation, the relative importance of crop production, the degree of grazing pressure in the system, and how restrictive public access policy is. We find that in the study area, interactions between all the previously mentioned elements covary consistently, generating bundles of ecosystem services associated with each of three management models based on the intensity of management.     

Spatial organization of multiple plant species in arid ecosystems: linking patterns and processes

Spatial organization of multiple plant species that appears as a non-random distribution of vegetative patches is one of the mostly observed spatial patterns in arid ecosystems. Yet understanding of ecological processes allowing this spatial pattern to emerge through interspecific interactions is still lacking. With a proposed conceptual model involving interspecific trade-offs between species competitive ability and colonization ability, we have argued that within patch abundance dynamics regulated by the mechanisms of competition are strongly influenced by the between patches colonization dynamics that are maintained via this trade-offs and it holds a positive, intraspecific occupancy-abundance relationship, in which increased patch occupancy increases species density within inhabiting patches. In a constant environment, while local abundance dynamics approach toward a stable equilibrium point, a fixed spatial arrangement of species can be retained through this coupled dynamics. However, in fluctuating environments where existence of such stable equilibriums is highly uncertain, it may involve continuous transitions from one community state to another as species re-organized themselves over space through the rapid changes in local species abundances. While some of the inhabiting patches are destroyed exogenously or endogenously, or species responses to increasing environmental fluctuations vary increasingly with time, discontinuous transitions into an abrupt, irreversible state of the community dynamics may occur, as with this effect the inherent positive relationship between occupancy and abundance of species is no longer maintained.     

Climate change and the genetics of insecticide resistance

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     

哈长城市群生态系统服务时空特征及其权衡/协同关系研究

哈长城市群位列国家二级城市群之首,研究哈长城市群地区的生态系统服务变化及权衡协同关系对促进该区域可持续发展具有深远意义。基于多源遥感数据结合InVEST模型及权衡协同度模型(ESTD),分析了哈长城市群2000年、2010年、2015年土地覆被变化;评估了土壤保持、生态系统碳储量及产水量3种生态系统服务的时空分布及其权衡协同关系。结果表明:(1)2000-2015年,哈长城市群内建设用地共增加1462 km²,其中,2000-2010年增长量(958 km²)高于2010-2015年(504 km²),15年间林地共增加1527 km²,草地、耕地及裸地分别减少661 km²,1611 km²,780 km²;(2)15年间土壤保持量持续降低,生态系统碳储量先减后增,产水量先增后减;(3)6种土地覆被类型中,单位面积下林地提供的土壤保持力最高,湿地提供的生态系统碳储量和产水量最高;(4)协同作用在哈长城市群3种生态系统服务间占主导地位;南部的土壤保持-生态系统碳储量及土壤保持-产水量多为协同关系,北部相反,从全区来看生态系统碳储量-产水量间的相关关系相对较弱。研究结果可为哈长城市群地区制定更为全面具体的生态保护策略提供参考依据。     

西藏草地多项供给及调节服务相互作用的时空演变规律

基于统计数据及MODIS产品,计算西藏草地2000与2010年载畜支持服务、肉类供给服务、水源涵养服务和碳吸收服务的功能量。构建Pearson相关系数、总生态系统服务(TES)、供给-调节服务互竞指数(TO),分析了4项生态系统服务相互作用关系随纬度、海拔及时间变化的规律。结果表明:西藏草地两项供给服务和两项调节服务之间分别为相互协同作用,且随时空变化不大。供给服务和调节服务之间的相互作用随海拔和纬度升高时,基本由相互竞争转变为相互协同,在高纬度时则无相互作用。4项服务在低纬度及低海拔呈相互竞争关系时,其生态系统服务总体水平也较低,中纬度及中高海拔呈协同关系时,其总体水平较高。从2000年到2010年,西藏草地4项生态系统服务皆发生较大变化。在变化中,12%的草地供给服务与调节服务发生相互竞争作用,33%的草地则为相互协同关系。发生相互竞争作用的草地主要集中在中低纬度的一江两河地区,而相互协同的区域主要为藏北羌塘高原中南部。     

基于InVEST模型的生态系统土壤保持功能研究——以福建宁德为例

基于InVEST模型,对宁德地区生态系统土壤保持功能的空间特征及其影响因素进行了分析。结果表明:宁德地区土壤保持总量为9.35×10⁸ t/a,单位面积土壤保持量为695.3 t/（hm²·a）,空间上呈现中部高,东北部次之,西南部低的分布格局,各县市差异显著;各生态系统土壤保持能力从大到小依次为:灌丛 > 林地 > 草丛 > 旱地 > 园地 > 水田 > 红树林 > 草本湿地 > 城镇,自然生态系统优于人工生态系统;除自然因素外,社会经济的迅速发展也是影响土壤保持功能的重要因素,其中单位面积GDP、单位面积第一产业生产总值、人口密度、第一产业劳动力密度、交通网络密度以及耕地比例与单位面积土壤保持量负相关,林地和草地的比例与土壤保持功能正相关。可见,宁德地区土壤保持功能差异性显著,并且与社会经济发展存在紧密联系,因此,在今后的发展中要权衡社会经济发展与土壤保持功能的关系,促进经济和生态环境和谐发展。     

基于PCA的耕地功能冲突与协同识别——以湖北省为例

[目的]以湖北省为例,识别耕地功能之间的冲突与协同关系及各耕地功能的强弱,为耕地多功能利用与管理提供技术支撑及决策信息。[方法]采用主成分分析法(PCA)进行识别论证。[结果](1)湖北省耕地的基本生活保障功能最强,生态安全维护功能次之,就业保障功能最弱;(2)湖北省耕地的基本生活保障功能、生态安全维护功能和就业保障功能之间、耕地的社会安定维护功能和粮食安全保障功能之间、耕地的就业保障功能、家庭经济贡献功能和国民经济贡献功能之间存在协同关系;(3)湖北省耕地的社会安定维护和粮食安全保障功能束与家庭经济贡献和国民经济贡献功能束之间存在显著的冲突关系。[结论]PCA法不仅可以表达各耕地功能的强弱,更能直观表达耕地功能间的冲突与协同关系以及冲突与协同的程度,为耕地多功能利用与管理提供了一定的技术支撑及决策支持。     

生态系统服务生产及输送和消费过程中的关键问题

文中对生态系统服务生产、输送和消费过程中的关键问题进行了探讨, 主要得出如下几方面结论:1)在生态系统服务生产过程中, 生态系统服务与生态系统功能之间不是一一对应的, 而且生态系统服务之间在生产过程中存在着相互作用。这种作用有单向和双向之分, 协同增效和相互抑制是生态系统服务之间2个非常普遍的相互作用, 各种驱动力因子对生态系统服务的生产有很大影响。2)生态系统服务效用的空间覆盖特征决定了它们是否能够被输送, 根据输送载体的不同, 输送方式主要有自然输送和人为输送2种。3)在生态系统服务消费的同时需要获得一定数量的资金投入来保证生态系统服务的再生产, 获取的途径主要有市场和生态补偿2方面, 起到关键作用的是生态补偿。