Combining two teaching techniques for young children on Aedes aegypti control: effects on entomological indices in western Mexico

A study of the effect of educating four- to six-year-old children in mosquito control was recently conducted in a city in the state of Jalisco, western Mexico. Four neighborhood districts were selected. Children attending one kindergarten in each of two experimental districts were taught mosquito control with a video from the American Mosquito Control Association (AMCA), joined to the use of the AMCA Touch Table Technique. The entomological indices monitored in the study decreased significantly (P<0.05) in houses in the experimental districts, apparently because parents acted on the comments and suggestions of the children and eliminated or monitored containers used as oviposition sites by mosquitoes. Based on these results, combining both techniques for teaching children mosquito control is a potentially useful tool for control efforts in Mexico and other places in Latin America.     

Fungicide-induced declines of freshwater biodiversity modify ecosystem functions and services

Although studies on biodiversity and ecosystem function are often framed within the context of anthropogenic change, a central question that remains is how important are direct vs. indirect (via changes in biodiversity) effects of anthropogenic stressors on ecosystem functions in multitrophic-level communities. Here, we quantify the effects of the fungicide chlorothalonil on 34 species-, 2 community- and 11 ecosystem-level responses in a multitrophic-level system. At ecologically relevant concentrations, chlorothalonil increased mortality of amphibians, gastropods, zooplankton, algae and a macrophyte (reducing taxonomic richness), reduced decomposition and water clarity and elevated dissolved oxygen and net primary productivity. These ecosystem effects were indirect and predictable based on changes in taxonomic richness. A path analysis suggests that chlorothalonil-induced reductions in biodiversity and top-down and bottom-up effects facilitated algal blooms that shifted ecosystem functions. This work emphasises the need to re-evaluate the safety of chlorothalonil and to further link anthropogenic-induced changes in biodiversity to altered ecosystem functions.     

Forecasting phenology: from species variability to community patterns

Shifts in species' phenology in response to climate change have wide-ranging consequences for ecological systems. However, significant variability in species' responses, together with limited data, frustrates efforts to forecast the consequences of ongoing phenological changes. Herein, we use a case study of three North American plant communities to explore the implications of variability across levels of organisation (within and among species, and among communities) for forecasting responses to climate change. We show how despite significant variation among species in sensitivities to climate, comparable patterns emerge at the community level once regional climate drivers are accounted for. However, communities differ with respect to projected patterns of divergence and overlap among their species' phenological distributions in response to climate change. These analyses and a review of hypotheses suggest how explicit consideration of spatial scale and levels of biological organisation may help to understand and forecast phenological responses to climate change.     

Diversity of plant evolutionary lineages promotes arthropod diversity

Large‐scale habitat destruction and climate change result in the non‐random loss of evolutionary lineages, reducing the amount of evolutionary history represented in ecological communities. Yet, we have limited understanding of the consequences of evolutionary history on the structure of food webs and the services provided by biological communities. Drawing on 11 years of data from a long‐term plant diversity experiment, we show that evolutionary history of plant communities – measured as phylogenetic diversity – strongly predicts diversity and abundance of herbivorous and predatory arthropods. Effects of plant species richness on arthropods become stronger when phylogenetic diversity is high. Plant phylogenetic diversity explains predator and parasitoid richness as strongly as it does herbivore richness. Our findings indicate that accounting for evolutionary relationships is critical to understanding the severity of species loss for food webs and ecosystems, and for developing conservation and restoration policies.     

Ecological assembly rules in plant communities—approaches,patterns and prospects

Understanding how communities of living organisms assemble has been a central question in ecology since the early days of the discipline. Disentangling the different processes involved in community assembly is not only interesting in itself but also crucial for an understanding of how communities will behave under future environmental scenarios. The traditional concept of assembly rules reflects the notion that species do not co‐occur randomly but are restricted in their co‐occurrence by interspecific competition. This concept can be redefined in a more general framework where the co‐occurrence of species is a product of chance, historical patterns of speciation and migration, dispersal, abiotic environmental factors, and biotic interactions, with none of these processes being mutually exclusive. Here we present a survey and meta‐analyses of 59 papers that compare observed patterns in plant communities with null models simulating random patterns of species assembly. According to the type of data under study and the different methods that are applied to detect community assembly, we distinguish four main types of approach in the published literature: species co‐occurrence, niche limitation, guild proportionality and limiting similarity. Results from our meta‐analyses suggest that non‐random co‐occurrence of plant species is not a widespread phenomenon. However, whether this finding reflects the individualistic nature of plant communities or is caused by methodological shortcomings associated with the studies considered cannot be discerned from the available metadata. We advocate that more thorough surveys be conducted using a set of standardized methods to test for the existence of assembly rules in data sets spanning larger biological and geographical scales than have been considered until now. We underpin this general advice with guidelines that should be considered in future assembly rules research. This will enable us to draw more accurate and general conclusions about the non‐random aspect of assembly in plant communities.     

A warrant for applied palaeozoology

It has been argued by some neozoologists (those who study living animals) that the palaeozoological record is biased and incomplete (relative to an existing biological community) and therefore should not be consulted for purposes of conservation biology. An article published in a biology journal in 2011 lists numerous reasons why natural history collections (NHCs) of skins and skulls of animals collected over the past century or two are exceptionally valuable to conservation biologists because those collections provide significant time depth to numerous variables that document global biological change. Many of those same variables can be, and have been, identified in the palaeozoological record. Those variables are of major value to conservation biology, whether their values are taken from 100‐year‐old NHCs or from palaeozoological remains. Empirical examples in which the identified variables are measured in palaeozoological contexts indicate that the palaeozoological record should indeed be consulted by conservation biologists and can no longer be considered unsatisfactory for modern resource management.     

乌兰布和沙漠典型灌木群落结构及数量特征

灌木群落是乌兰布和沙漠生态系统中最重要的组成部分,根据野外样地的调查资料,从各群落物种组成、生活型谱、盖度特征、物种多样性、群落相似性等方面对乌兰布和沙漠中典型灌木群落结构和数量特征进行分析,为该区生物多样性保护与植物资源持续利用提供理论依据。结果表明:(1)梭梭、白刺、沙冬青、沙蒿、油蒿、盐爪爪是乌兰布和沙漠中主要灌木群落类型;各典型灌木植被群落中仅出现12科47属共计58种植物,各群落间物种组成差异较大,但均以藜科、菊科、禾本科、蒺藜科、豆科等干旱荒漠区的表征科数量居多;(2)沙漠中分布范围最广的梭梭群落、白刺群落、沙冬青群落和油蒿群落其生活型谱均以一年生植物所占比例最大,与研究区干旱的气候特征相吻合;(3)各群落中灌木层植物所占群落盖度的比重均超过了50%,其贡献率大于草本植物;(4)分布于生境条件较好的群落类型其物种多样性相对较高,从整体看各典型灌木群落的H′多样性指数的变化范围在0.98～3.42之间,而D多样性指数的变化范围在0.415 5～0.879 5之间,其物种多样性指数较低,物种组成比较简单;(5)各典型植物群落的相似性系数在0.068 2～0.604 7之间,均未达到极相似水平,其中白刺群落、梭梭群落以及沙冬青群落之间呈轻度相似水平,而其他各群落之间相似性系数均低于0.25,表明各群落间生境差异较大。