A major goal of phylogeographic analysis using molecular markers is to understand the ecological and historical variables that influence genetic diversity within a species. Here, we used sequences of the mitochondrial Cox1 gene and nuclear internal transcribed spacer to reconstruct its phylogeography and demographic history of the intertidal red seaweed Chondrus ocellatus over most of its geographical range in the Northwest Pacific. We found three deeply separated lineages A, B and C, which diverged from...

Although extensive studies demonstrate that nitrogen (N) enrichment frequently reduces plant diversity within small quadrats (0.5 –4 m2), only a few studies have evaluated N effects on biodiversity across different spatial scales. We conducted the first experimental test of the scale dependence of N effects on species richness from a 10-year N treatment (1.75- 28 g N m−2 yr−1) in a typical steppe. We used species area relationship (SAR) to analyze the scale dependence of...

Ecological speciation plays a primary role in driving species divergence and adaptation. Oryza rufipogon and Oryza nivara are two incipient species at the early stage of speciation with distinct differences in morphology, life history traits and habitat preference, and therefore provide a unique model for the study of ecological speciation. However, the population genetic structure of the ancestral O. rufipogon has been controversial despite substantial study, and the origin of the derivative O. nivara remains...

Vascular epiphytes are an understudied and particularly important component of tropical forest ecosystems. However, owing to the difficulties of access, little is known about the properties of epiphyte-host tree communities and the factors structuring them, especially in Asia. We investigated factors structuring the vascular epiphyte-host community and its network properties in a tropical montane forest in Xishuangbanna, SW China. Vascular epiphytes were surveyed in six plots located in mature forests. Six host and four micro-site...

The origin and evolution of polyploids have been studied extensively in angiosperms and ferns but very rarely in gymnosperms. With the exception of three species of conifers, all natural polyploid species of gymnosperms belong to Ephedra, in which more than half of the species show polyploid cytotypes. Here we investigate the origin and evolution of polyploids of Ephedra distributed in the Qinghai-Tibetan Plateau (QTP) and neighboring areas. Flow cytometry (FCM) was used to measure the...

Mammals developed antioxidant systems to defend against oxidative damage in their daily life. Enzymatic antioxidants and low molecular weight antioxidants (LMWAs) constitute major parts of the antioxidant systems. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2, encoded by the Nrf2 gene) is a central transcriptional regulator, regulating transcription, of many antioxidant enzymes. Frugivorous bats eat large amounts of fruits that contain high levels of LMWAs such as vitamin C, thus, a reliance on LMWAs might greatly reduce...

Microgravity is a major stress factor that astronauts have to face in space. In the past, the effects of microgravity on genomic DNA damage were studied, and it seems that the effect on genomic DNA depends on cell types and the length of exposure time to microgravity or simulated microgravity (SMG). In this study we used mouse embryonic stem (MES) and mouse embryonic fibroblast (MEF) cells to assess the effects of SMG on DNA lesions....

Recent advances in high-throughput sequencing technologies have offered the possibility to generate genome-wide sequence data to delineate previously unidentified genetic structure, obtain more accurate estimates of demographic parameters, and to evaluate potential adaptive divergence. Here, we identified 27 556 single-nucleotide polymorphisms for the small yellow croaker (Larimichthys polyactis) using restriction-site-associated DNA (RAD) sequencing of 24 individuals from two populations. Significant sources of genetic variation was identified, with an average nucleotide diversity (π) of 0.00105 ±...

1. Bee populations and other pollinators face multiple, synergistically acting threats, which have led to population declines, loss of local species richness and pollination services, and extinctions. However, our understanding of the degree, distribution and causes of declines is patchy, in part due to inadequate monitoring systems, with the challenge of taxonomic identification posing a major logistical barrier. Pollinator conservation would benefit from a high-throughput identification pipeline. 2. We show that the metagenomic mining and...

A well-covered reference library is crucial for successful identification of species by DNA barcoding. The biggest difficulty in building such a reference library is the lack of materials of organisms. Herbarium collections are potentially an enormous resource of materials. In this study, we demonstrate that it is likely to build such reference libraries using the reconstructed (self-primed PCR amplified) DNA from the herbarium specimens. We used 179 rosaceous specimens to test the effects of DNA...

Among above- and belowground traits, specific leaf area (SLA, cm2 g−1) and specific root length (SRL, m g−1) are the two key traits reflecting species resource acquisition strategies. However, patterns of variation in SLA and SRL have rarely been examined simultaneously across evolutionary history and environmental gradients, and the SLA-SRL relationship is still controversial on several grounds. We examined the inter- and intraspecific variations in SLA and SRL of different root branching orders and the...

We evaluated the phylogeography and historical demography of the cyprinid fish Gymnodiptychus dybowskii (subfamily Schizothoracinae) across three northern Qinghai-Tibetan Plateau (QTP) river systems in the Tien Shan range: the Kaidu River, Ili River and Junggar Basin. Results from both mtDNA (16S rRNA and Cyt b) and nuDNA (RAG-2) resolved three reciprocally monophyletic clades, one in each of the three river basins. Estimated divergence times (highest posterior density (HPD) 2.4–3.7 Mya) are consistent with the hypothesis...

Many non-rewarding orchid species mimic the signals of co-occurring food flowers and thereby attract food-seeking animal pollinators. These signals are often visually complex with a colour pattern that contrasts between outer and central parts. The significance of this colour complexity for the pollination success of flowers of deceptive orchids has scarcely been investigated. We tested the effects of the colour patterns of the food-deceptive orchid Paphiopedilum micranthum on bumblebee visitation choices and pollination success using...

1. Improved understanding of the carbon (C) cycle is essential to model future climates and how this may feedback to affect greenhouse-gas fluxes. 2 .We summarize previous work quantifying respiration rates of organic substrates and briefly discuss how advances in technology, specifically the use of chambers linked to a non-dispersive infra-red gas analyzer (NDIR), can be applied to assess carbon dynamics from short-term field measurements. This technology hastens measurement and is relatively inexpensive, enabling researchers...

Global climate change is known to affect the assembly of ecological communities by altering species’ spatial distribution patterns, but little is known about how climate change may affect community assembly by changing species’ temporal co-occurrence patterns, which is highly likely given the widely observed phenological shifts associated with climate change. Here we analyzed a 29-year phenological data set comprising community-level information on the timing and span of temporal occurrence in 11 seasonally occurring animal taxon...

Deforestation and forest degradation are driving unprecedented declines in biodiversity across the tropics, and understanding the consequences of these changes for ecosystem functioning is essential for human well-being. Forest degradation and loss alter ecosystem functioning through changes in species composition and abiotic conditions. However, the consequences of these changes for heterospecific processes are often poorly understood. Leaf litter decomposition is a major source of atmospheric carbon and critical for carbon and nutrient cycling. Through a...

Tropical forests represent a major terrestrial store of carbon (C), a large proportion of which is contained in the soil and decaying organic matter. Woody debris plays a key role in forest C dynamics because it contains a sizeable proportion of total forest C. Understanding the factors controlling the decomposition of organic matter in general, and woody debris in particular, is hence critical to assessing changes in tropical C storage. We conducted a factorial fertilization...

The decomposition of wood inside living tree hollows influences forest structure and processes. Although the decomposition rate controls the formation of hollows, it has not previously been measured. In an old-growth subtropical montane evergreen broad-leaved forest in south-west China, we measured respiration rates of decaying wood inside living tree hollows, logs (downed tree trunks) and snags (standing dead trees) using infrared CO2 analysis. We compared stem radial growth rates to the horizontal expansion rates of...

Understanding the mechanisms that govern the spatial patterns of species turnover (beta diversity) has been one of the fundamental issues in biogeography. Species turnover is generally recognized as strong in mountainous regions, but the way in which different processes (dispersal, niche, and isolation) have shaped the spatial turnover patterns in mountainous regions remains largely unexplored. Here, we explore the directional and elevational patterns of species turnover for nonvolant small mammals in the Hengduan Mountains of...