基于生态位理论的柑橘生境适宜性评价研究现状及思路

[目的]基于生态位理论,对柑橘生境适宜性评价研究现状及思路进行分析。[方法]对生境适宜性评价、生态位理论在作物生境选择方面的研究现状进行综合分析。[结果]提出了借助生态位理论开展品质约束的柑橘生境适宜评价的研究思路,包括3方面,即柑橘生态环境及品质因子的采集与表达、柑橘生态环境与品质的交互响应研究、基于品质约束的柑橘生境适宜评价与适应机制研究。[结论]为促进柑橘产业化发展提供了借鉴。     

Host range as an axis of niche partitioning in the plant-feeding nematode community of banana agroecosystems

The stability and positive functions (such as pest regulation) of intensively managed agroecosystems can be enhanced by increasing biodiversity (in particular, by introducing cover plants or associated crops). Therefore, understanding modes of interspecific interactions among the phytophagous species, such as coexistence via host-plant partitioning, may allow manipulation of the balance between pest and non-pest species.In the present study, we tested the hypothesis that a community of six plant-feeding nematode species in banana agroecosystems is structured by host plants. This was done using extensive data on the abundance of the different nematodes species on banana and associated weeds in Martinique. Because the purpose of this study was to focus on host-plant range, we eliminated the effects of temperature, rainfall, and soil type using a partial canonical correspondence analysis.Host plants in banana agroecosystems have a marked influence on the plant-feeding nematode community structure. Host plants allow niche partitioning between some but not all pairs of species. The most evident pattern is the niche partitioning among the three nematodes considered long established in Martinique.For pairs of species showing no host-plant niche partitioning, additional information regarding the colonisation and population dynamics over time both at the root and agroecosystem scale would allow better understanding of the equilibrium among species of the plant-feeding nematode community.For management purposes, the modification of abundance of some host plants, which could be used as cover plants in the field, could change the balance among nematode species.     

农户与龙头企业共生合作路径研究——基于生态位理论仿真分析

为探究农户和农业龙头企业共生合作的路径,借鉴生态位理论和共生理论,构建合作程度测度模型,通过Matlab软件对模型的相关变量进行了仿真分析。根据仿真分析结果,为农户与龙头企业共生合作提出了相应政策建议。     

不同除草方式对稻田杂草群落及其多样性的影响

为了解不同除草方式[人工除草(A_(01))和化学除草(B_(01))]稻田杂草群落和生物多样性的现状,2016年对新疆伊犁河谷2种不同除草方式稻田杂草重要值、生态位宽度和生态位重叠值进行研究。结果表明:A_(01)和B_(01)稻田杂草种类分别有10目11科12属14种和6目7科10属11种,2种模式杂草群落结构类似,为阔叶类杂草+莎草科杂草+禾本科杂草;A_(01)重要杂草和主要杂草为B_(01)的1.33倍和1.50倍;A_(01)扁秆藨草生态位宽度(0.838 2)最大,B_(01)长芒稗生态位宽度(0.895 9)最大;B_(01)中长芒稗、空心莲子草、扁秆藨草生态位宽度均高于0.6且长芒稗-空心莲子草(A_(01):0.814 8,B_(01):0.790 9)、长芒稗-扁秆藨草(A_(01):0.838 0,B_(01):0.735 3)和空心莲子草-扁秆藨草(A_(01):0.967 9,B_(01):0.614 5)的生态位重叠值也均高于0.6,说明不同除草方式下,稻田杂草种间竞争格局发生改变,长芒稗、空心莲子草和扁秆藨草逐步演替为调查区主要杂草且其在B_(01)稻田表现出抗药性。     

稻田蜘蛛的空间生态位的初步研究

生态位理论是现代生态学中的一个重要内容,现正日益受到人们的重视。多维生态位概念提出之后,这方面的研究又有了新的发展。生态位定量描述主要包括两方面:一是生态位宽度(Niche Breadth),即被某一生物种所利用的各种不同资源的总和。其次是生态位重叠(Niche Overlap),即几个生物种共同分享或竞争一个已知栖息资源的程度。这两个方面的测定可反映出群落中各个物     

天然次生林主要种群生态位结构的研究

文章应用生态位理论。对组成东北东部地区天然次生林群落中１０个主要种群（水曲柳、胡桃楸、黄波罗、椴树,山杨,白桦,枫桦,榆,色木械,蒙古栎）进行了生态位结构的初步研究。分别采用三种常见的生态位宽度和生态位重叠计测公式。     

陇南桔园昆虫群落生态位及时序动态研究

报道了陇南桔园昆虫群落生态位和时序动态规律。用群落生态方法探讨了各种群的竞争共存机制。结果表明,４种主要害虫在树冠上各占据相应的生态位。矢尖蚧和吹绵蚧的竞争主要表现在空间分化上;桔全爪螨占有较大的空间,而在时间序列上出现频率小;桔蚜占据较小的空间。     

绵阳官司河流域天然次生林种群的生态位特征

基于绵阳官司河流域天然次生林群落57块100 m~2的样地调查数据,以微地形地貌作为一维资源位状态,以物种的重要值为生态位计测的资源状态指标,对该流域主要乔木、灌木种群的生态位宽度、生态位相似性和生态位重叠进行了计算与分析。结果表明,主要优势种群的生态位宽度较大,乔木层主要优势种群马尾松、柏木、栓皮栎等Levins生态位宽度值分别为0.841、0.816、0.907,灌木层主要优势种群铁仔、三颗针、黄荆、火棘等Levins生态位宽度值分别为0.985、0.965、0.952、0.882。群落中各种群之间的生态位关系较复杂,生态位宽度较大的物种对资源利用能力较强,彼此之间的生态位相似性和生态位重叠值较大,对资源具有一定的共享性,存在生态位分离现象。种群之间的生态位相似比例和生态位重叠值分布状况,反映了该流域植被恢复过程中森林群落的生态位特征。     

浙江丽水太山山地常绿阔叶林主要种群生态位研究

对浙江丽水太山山地常绿阔叶林中的10个主要乔木种群生态位宽度和生态位相似性比例及生态位重叠进行了研究。结果表明:(1)研究区主要树种的生态位宽度大小顺序为:甜槠>木荷>褐叶青冈>青冈>苦槠>米槠>枫香树>石栎>虎皮楠>多花泡花树;(2)生态位相似性比例大于0.4的仅有36对,占80%,表明群落内物种对资源利用相似性程度较高;(3)生态位重叠指数大于0.4的共有38对,占84.44%,说明生态位重叠的程度很高。     

Effects of an exotic prey species on a native specialist: Example of the snail kite

Despite acknowledging that exotic species can exhibit tremendous influence over native populations, few case studies have clearly demonstrated the effects of exotic prey species on native predators. We examined the effects of the recently introduced island apple snail (Pomacea insularum) on the foraging behavior and energetics of the endangered snail kite (Rostrhamus sociabilis plumbeus) in Florida. We conducted time-activity budgets: (i) on kites foraging for native Florida apple snails (Pomacea paludosa) in major wetland units within the kites’ range that had not been invaded by the exotic island apple snail and (ii) on kites foraging for exotic apple snails in Lake Tohopekaliga, the only major wetland utilized by the snail kite that had suffered a serious invasion of P. insularum. When foraging for P. insularum, snail kites dropped a greater proportion of snails, and they experienced increased handling times and decreased consumption rates; however, kites foraging for P. insularum also spent a smaller proportion of the day in flight. Estimates of net daily energy balances between kites feeding on P. insularum versus P. paludosa were comparable for adults, but juveniles experienced energetic deficiencies when feeding on the exotic snail. Due to this discrepancy, we hypothesize that wetlands invaded by P. insularum, such as Lake Tohopekaliga, may function as ecological traps for the snail kite in Florida by attracting breeding adults but simultaneously depressing juvenile survival. This study highlights the conservation implications and importance of elucidating the effects that exotic species have on native specialists, especially those that are endangered, because subtle influences on behavior may have significant population consequences.