湖北黄冈大崎山药用苔藓植物调查研究

对湖北黄冈大崎山药用苔藓植物资源进行了初步调查研究,结果表明:黄冈大崎山共有药用苔藓植物17种,隶属13科15属,约占全国药用苔藓植物总数的29.3%;本文还记述了黄冈大崎山药用苔藓植物的分布及药用功能,并提出了合理性开发利用的思路。     

Responses of Terrestrial Antarctic Ecosystems to Climate Change

Antarctic terrestrial biota are generally limited by the inexorably linked environmental factors of low summer temperature and lack of available water. However, in parts of the Antarctic, both these factors are changing rapidly on contemporary timescales. Terrestrial biota have concurrently been faced with changes in the timing of UV-B maxima associated with spring ozone depletion. The region of the Antarctic Peninsula and Scotia Arc has experienced one of the most rapid rates of environmental warming seen worldwide over the last 30–50 years. Together with local changes in precipitation, this has resulted in a rapid reduction in extent and thinning of many ice-fields and glaciers, exposing new terrain for colonisation while, at the same time, altering patterns of water availability in terrestrial habitats. The rapid development of communities on newly-exposed ground is also facilitated by the existence of soil propagule banks, which contain propagules of both local and exotic origin. In this paper we collate and review evidence from a range of observational and manipulative studies that investigate the effect of climate change, especially increased temperature, on the processes of colonisation and subsequent community development by plants in the Antarctic. Biological changes that have been associated with climate change are visible in the form of expansions in range and local population numbers amongst elements of the flora. Environmental manipulation experiments further demonstrate the possibility of large and rapid species and community responses to climate amelioration, with many resident biota responding positively, at least in the absence of increased competition from exotic colonists. Manipulation studies are also starting to elucidate more subtle responses to climate changes, at levels ranging from cell biochemistry to habitat and food web structure. Integrating such subtle responses is vital to improving our ability to understand the consequences of climate change, as these may lead to much greater consequential impacts on communities and ecosystems.      

A GIS-based Model of the Distribution of the Rare Liverwort Aneura maxima at the Landscape Scale for an Improved Assessment of Its Conservation Status

Testing whether rare species are limited by narrow habitat conditions from correlations between species occurrence and measured environmental factors is usually hampered by the lack of statistical power associated to the low number of observations. Aneura maxima is an exceedingly rare liverwort in Europe whose recent discovery precluded the inclusion within the Red Data Book of European bryophytes. A series of new observations resulting from intensive bryophyte grid-mapping at the border between France and Belgium allowed the statistical investigation of the factors accounting for its distribution at the landscape scale. The species was systematically observed in deep ravines on damp, loamy soils under light tree cover within broadleaf woodlands. These conditions differ from those of other European localities, suggesting that A. maxima is not limited by a narrow ecological range. Attempting to predict the occurrence of A. maxima at the landscape scale from data on land use and soil conditions resulted in a model where the species was actually observed in only a half of the squares where its probability of occurrence was the highest. The species thus does not seem to have colonized all its potential habitats, which may be explained by the poor dispersal ability of this dioecious, rarely fertile species. Given the relative frequency of A. maxima in the Semois river basin, but taking into account its seemingly low dispersal ability and its preference for swampy habitats that are threatened by draining and spruce plantations, a status as 'conservation dependent' to 'near threatened' within the category 'lower risk' is proposed.     

Predictors of moss and liverwort species diversity of microsites in conifer‐dominated boreal forest

Patterns of moss and liverwort species diversity — species richness and species turnover (β‐diversity) — in three conifer‐dominated boreal forest stands of northern Alberta, Canada are described. We examined the relationship between bryophyte species diversity and micro‐environment at two sample grains, the microsite — substrate types for moss colonization: logs, stumps, tree bases, undisturbed patches of forest floor (dominated by feather moss species), and disturbed patches of forest floor — and the mesosite (25 m × 25 m plots). Microsite type and properties (e.g. decay class, hardwood vs softwood, pH) were the principal predictors of bryophyte species diversity and not micro‐environment variation among mesosites. Microsite type was the strongest predictor of microsite species richness and β‐diversity was higher among microsites and types and within microsites than among mesosites or stands. Microsite properties were significant predictors of species richness for all microsite types. Log and stump decay classes, influenced also by hardwood vs softwood predicted species richness of woody microsite types and soil pH and moisture predicted species richness of forest floor microsites. β‐diversity was highest for tree bases and disturbed patches of forest floor and lowest for logs. Mesosite β‐diversity was lower than that among microsites, and mesosite species richness was not well explained by measured environmental parameters. Results suggest that in conifer‐dominated boreal stands, species richness of microsites is only negligibly influenced by within‐stand variation at the mesosite grain and that substrate characteristics are the most important predictors of bryophyte species diversity in this ecosystem.     

Diversity of dry forest epiphytes along a gradient of human disturbance in the tropical Andes

Question: Disturbance effects on dry forest epiphytes are poorly known. How are epiphytic assemblages affected by different degrees of human disturbance, and what are the driving forces? Location: An inter‐Andean dry forest landscape at 2300 m elevation in northern Ecuador. Methods: We sampled epiphytic bryophytes and vascular plants on 100 trees of Acacia macracantha in five habitats: closed‐canopy mixed and pure acacia forest (old secondary), forest edge, young semi‐closed secondary woodland, and isolated trees in grassland. Results: Total species richness in forest edge habitats and on isolated trees was significantly lower than in closed forest types. Species density of vascular epiphytes (species per tree) did not differ significantly between habitat types. Species density of bryophytes, in contrast, was significantly lower in edge habitat and on isolated trees than in closed forest. Forest edge showed greater impoverishment than semi‐closed woodland and similar floristic affinity to isolated trees and to closed forest types. Assemblages were significantly nested; habitat types with major disturbance held only subsets of the closed forest assemblages, indicating a gradual reduction in niche availability. Distance to forest had no effect on species density of epiphytes on isolated trees, but species density was closely correlated with crown closure, a measure of canopy integrity. Main conclusions: Microclimatic changes but not dispersal constraints were key determinants of epiphyte assemblages following disturbance. Epiphytic cryptogams are sensitive indicators of microclimate and human disturbance in montane dry forests. The substantial impoverishment of edge habitat underlines the need for fragmentation studies on epiphytes elsewhere in the Tropics.     

新疆博格达山地面生苔藓植物物种多样性研究

采用相似性系数和物种多样性指数对新疆博格达山地面生苔藓植物的物种多样性进行了研究．结果表明,博格达山地区苔藓植物区系具有丰富性和复杂性的特点,共有地面生苔藓植物32科73属186种(含变种、变型);山地荒漠带和山地草原带苔藓植物物种相似性最高,为0．6809,山地森林带和高山垫状植被带相似性最低,仅为0．1342;山地森林带苔藓植物在整个博格达山地面生苔藓植物群落中占据优势地位;山地森林带苔藓植物物种多样性最为丰富,为该山地苔藓植物多样性的分布中心,是苔藓植物多样性保护的关键地区．     

Large‐scale longitudinal gradients of genetic diversity: a meta‐analysis across six phyla in the Mediterranean basin

Biodiversity is the diversity of life at all scales, from genes to ecosystems. Predicting its patterns of variation across the globe is a fundamental issue in ecology and evolution. Diversity within species, that is, genetic diversity, is of prime importance for understanding past and present evolutionary patterns, and highlighting areas where conservation might be a priority. Using published data on the genetic diversity of species whose populations occur in the Mediterranean basin, we calculated a coefficient of correlation between within‐population genetic diversity indices and longitude. Using a meta‐analysis framework, we estimated the role of biological, ecological, biogeographic, and marker type factors on the strength and magnitude of this correlation in six phylla. Overall, genetic diversity increases from west to east in the Mediterranean basin. This correlation is significant for both animals and plants, but is not uniformly expressed for all groups. It is stronger in the southern than in the northern Mediterranean, in true Mediterranean plants than in plants found at higher elevations, in trees than in other plants, and in bi‐parentally and paternally than in maternally inherited DNA makers. Overall, this correlation between genetic diversity and longitude, and its patterns across biological and ecological traits, suggests the role of two non‐mutually exclusive major processes that shaped the genetic diversity in the Mediterranean during and after the cold periods of the Pleistocene: east‐west recolonization during the Holocene and population size contraction under local Last Glacial Maximum climate in resident western and low elevation Mediterranean populations.