The evolutionary ecology of the Lygaeidae

The Lygaeidae (sensu lato) are a highly successful family of true bugs found worldwide, yet many aspects of their ecology and evolution remain obscure or unknown. While a few species have attracted considerable attention as model species for the study of insect physiology, it is only relatively recently that biologists have begun to explore aspects of their behavior, life history evolution, and patterns of intra‐ and interspecific ecological interactions across more species. As a result though, a range of new phenotypes and opportunities for addressing current questions in evolutionary ecology has been uncovered. For example, researchers have revealed hitherto unexpectedly rich patterns of bacterial symbiosis, begun to explore the evolutionary function of the family's complex genitalia, and also found evidence of parthenogenesis. Here we review our current understanding of the biology and ecology of the group as a whole, focusing on several of the best‐studied characteristics of the group, including aposematism (i.e., the evolution of warning coloration), chemical communication, sexual selection (especially, postcopulatory sexual selection), sexual conflict, and patterns of host‐endosymbiont coevolution. Importantly, many of these aspects of lygaeid biology are likely to interact, offering new avenues for research, for instance into how the evolution of aposematism influences sexual selection. With the growing availability of genomic tools for previously “non‐model” organisms, combined with the relative ease of keeping many of the polyphagous species in the laboratory, we argue that these bugs offer many opportunities for behavioral and evolutionary ecologists.     

Population biology of two land snails (Mesomphix spp.): variation among six southern appalachian sites with differing disturbance histories

Summary Ecological and genetic properties of two North American terrestrial gastropods (Mesomphix spp.) were characterized in paired control and previously logged watersheds in two North Carolina forests (Coweeta and the Great Smoky Mountains National Park) of the Southern Appalachian Biosphere Reserve Cluster. Shell growth was greater in the control sites, but density and mortality were largely independent of prior logging history and forest reserve. Based on starch gel electrophoresis data, both species showed their highest levels of genetic diversity in the Coweeta forest, the component of the reserve cluster which had the most extensive and variable history of logging disturbance. M. subplanus also exhibited higher levels of heterozygosity in logged than in control watersheds, and M. andrewsae showed over twice as many rare alleles in disturbed sites as in control sites. F-statistic analysis depicted both excess levels of homozygosity and moderate genetic differentiation among the populations, reflecting the effects of small population size and perhaps drift and inbreeding. Estimated gene flow was relatively low. These results correspond to the recent finding by Bryant et al. (1987) and others on the effects of bottlenecks, and to the contrasting history of habitat instability of the two major study forests.     

Species composition and distribution of Coleosporium species on the needles of Pinus densiflora at a semi-natural vegetation succession site in central Japan

Coleosporium species cause pine needle rust. Most species have heteromacrocyclic life cycles, and 12 species use Pinus densiflora as aecial hosts. To understand the biology of rust fungi and develop better methods for controlling rust diseases, it is necessary to clarify that which Coleosporium species affect pine trees. However, Coleosporium on pine trees have rarely been identified at the species level because of their morphological similarities. We used polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) to clarify the species composition, abundance, and distribution of Coleosporium in a P. densiflora forest. We surveyed a site where several Coleosporium species might complete their life cycles. PCR-RFLP revealed four species on the pines: C. asterum, C. clematidis-apiifoliae, C. lycopodis, and C. phellodendri. Coleosporium phellodendri was distributed throughout the forest and was the most abundant. Aecia of C. phellodendri formed mainly on 2-y-old needles. The abundance and distribution of C. phellodendri appeared to be affected by the longer effective dispersal range of basidiospores and the existence of abundant inoculum sources. The age of leaves where C. phellodendri form aecia mainly was thought to be influenced by the characteristic life cycle, with aecial formation requiring 2?y after basidiospore infection.     

Ectomycorrhizal fungi diversity in a white sand forest in western Amazonia

The genera Dicymbe and Aldina (Fabaceae) host ectomycorrhizal fungi (EcM) and are common in white sand forests (WSFs), a highly specialized habitat with a high level of plant endemism compared with terra-firme forests. In this study, we visited four times a 1-ha permanent plot established in a small patch of a WSF in the south of Colombia Amazonia. Forty-eight species of EcM fungi were recovered from sporocarps and 15 ITS species-level were detected from root tips. Seventeen species were new reports to Colombia and seven corresponded to undescribed species. These results confirm that this WSF supports a significant EcM fungal diversity. Most of the species found in this study have been previously reported to be associated with other legume and/or dipterocarp species from geographically distant forests. The long-distance occurrence combined with low host specificity, suggest the possibility of gene flow between geographically distant populations of EcM fungi in neotropical lowland rainforests.     

Plant selenium hyperaccumulation- Ecological effects and potential implications for selenium cycling and community structure

Background

Selenium (Se) hyperaccumulation occurs in ~50 plant taxa native to seleniferous soils in Western USA. Hyperaccumulator tissue Se levels, 1000–15,000?mg/kg dry weight, are typically 100 times higher than surrounding vegetation. Relative to other species, hyperaccumulators also transform Se more into organic forms.

Sphagnum divinum (sp. nov.) and S. medium Limpr. and their relationship to S. magellanicum Brid.

Sphagnum magellanicum has been viewed as being a predominantly circumpolar species in the northern hemisphere, but it occurs in the southern hemisphere and was originally described from the southern parts of Chile. It is an ecologically important species in mire ecosystems and has been extensively used as a model to study processes of growth, carbon sequestration and peat decomposition. Molecular and experimental studies have, however, revealed genetic structure within S. magellanicum, and morphological differences associated with these genetic groups. Here we describe Sphagnum divinum in Sphagnum subgenus Sphagnum (Sphagnaceae, Bryophyta) as a new species, based on molecular and morphological evidence. Sphagnum medium is reinstated as a distinct species and is epitypified. Consequently, a new species concept of S. magellanicum is presented including an epitypification. Important morphological characters to separate these three species in the field and under the microscope are presented. Ecology and distribution differ among the species; S. divinium has a wide habitat range including mire margin, forested peatlands and moist heaths, and a circumpolar distribution around the northern hemisphere. Sphagnum medium seems to be more restricted to ombrotrophic mire expanse habitats and shows an amphi-Atlantic distribution in the northern hemisphere. Sphagnum magellanicum has a very broad ecological niche in peatlands and is found in most mire habitats in Tierra del Fuego on the southern tip of South America.     

本科生英文文献阅读能力培养的探索——“微生物生态学”课程教学中的改革实践

本文介绍了华中农业大学在"微生物生态学"教学过程中进行的双语教学和前沿英文文献开卷阅读测试的实践案例。连续三年的教改实践有效帮助本科生克服了英文文献阅读的恐惧心理,提高了本科生阅读专业前沿文献的理解能力,调动了学习的积极性,创新思维能力有明显提高。     

First inventory of the Crustacea (Decapoda,Stomatopoda) of Juan de Nova Island with ecological observations and comparison with nearby islands in the Mozambique channel (Europa,Glorieuses, Mayotte)

Crustacea Decapoda and Stomatopoda are inventoried for the first time in Juan de Nova Island, Iles Eparses, Mozambique channel. In total, 112 species are reported: 69 crabs, 28 anomurans, 11 shrimps, 3 mantis shrimps and 1 lobster. A comparison is made with nearby islands in the Mozambique channel: Glorieuses Islands (157 species), Europa Island (178 species), and Mayotte Island (505 species). The lower species richness at Juan de Nova is explained by the small size of the island and by the difficulties to collect the crustaceans on the reef flat hardly accessible at low tide. The crustaceans are listed by main habitats from land to outer reef (2–20 m). The presence of the coconut crab (Birgus latro), an endangered species vulnerable to human predation, is confirmed.     

On the Nature and Significance of Variability in Lions (Panthera leo)

Although the lion is one of nature’s best-known species, much remains to be learned about its variability. Recently documented variation in genetics, morphology, ecology and behavior help to explain its adaptability and illustrate the inter-dependencies of biological responses at different organizational scales.     

Paleontological Patterns, Macroecological Dynamics and the Evolutionary Process

Here we consider evolutionary patterns writ large in the fossil record. We argue that Darwin recognized but downgraded or de-emphasized several of these important patterns, and we consider what a renewed emphasis on these patterns can tell us about the evolutionary process. In particular, one of the key patterns we focus on is the role geographic isolation plays in fomenting evolutionary divergence; another one of the key patterns is stasis of species; the final pattern is turnovers, which exist at several hierarchical scales, including regional ecosystem replacement and pulses of speciation and extinction. We consider how each one of these patterns are related to the dynamic of changing ecological and environmental conditions over time and also investigate their significance in light of other concepts including punctuated equilibria and hierarchy theory. Ultimately, we tie each of these patterns into a framework involving macroecological dynamics and the important role environmental change plays in shaping evolution from the micro- to macroscale.