Temporal Dynamics of Sediment Transport and Transient In‐channel Storage in a Highly Erodible Catchment

Elucidating the links between catchment and channel geomorphic processes helps the understanding of landscape evolution and the geomorphic development of river basins, and then the land degradation processes. In this study, we analyse suspended sediment dynamics and its relationship with rainfall, discharge and in‐channel sediment storage in a highly dynamic Mediterranean montane catchment (the River Isáben, Southern Pyrenees, NE Iberian Peninsula). The aim is to assess hydrological controls on and temporal patterns of the suspended sediment load. High loads in this basin occur as a consequence of intense erosion in badlands located in the middle of the catchment. This study focuses on a reach located downstream from the main badland areas, where rainfall, discharge (Q), sediment transport (SSC) and in‐channel sediment storage were monitored for a 1‐year period. Marked seasonality in water and sediment load was observed; whereas most of the discharge occurred in winter and spring, most of the sediment was transported during summer and autumn. Q‐SSC hysteretic loops revealed the importance of sediment availability (whether stored in the channel or originating from wider catchment source areas) in the river's sedimentary response. Clockwise loops dominated during winter and spring, whereas counter‐clockwise loops occurred mostly in summer and autumn, when in‐channel storage reached its maximum. There were significant correlations between rainfall intensity in the sediment source areas, in‐channel sediment storage and sediment yield. These correlations emphasize the importance of understanding sediment availability when analysing the temporal dynamics of sediment transport, especially in catchments where different source areas (slopes and riverbed) may contribute to the load to differing degrees and at different times of the year. Copyright © 2015 John Wiley & Sons, Ltd.     

试论南方集体林区林木采伐管理技术路线取向

森林资源管理职能在森林资源可持续发展过程中占有十分重要的地位，林木采伐管理是森林资源管理系统的有机组成部分，是森林资源管理的核心内容，直接关系到森林资源管理的成败。本文作者以南方集林区林木采伐管理的现状及特点，遵循森林资源可持续发展的有关原则，论述集体林区林木采伐管理技术路线取向。     

Acclimation to sun and shade of three accessions of the Chilean native berry-crop murta

Murta (Ugni molinae Turcz.) is an evergreen shrub of the native forest understorey of southern Chile that produces berries which are consumed in the local markets. Because of the natural adaptation of murta to growing under the shade of trees, we propose that an adequate way of domesticating this species would be its cultivation in agroforestry systems. In order to assess the suitability of three murta accessions from different regions in southern Chile for their cultivation in such systems, we established a trial in which these accessions were submitted to six light transmittance levels (20%–100% of full solar irradiance) from planting in spring to the following autumn. Optimum growth, as assessed through dry mass accumulation and emission of branches and metamers, was achieved at moderate light transmittance levels (50%–65%). These growth traits showed stable positive responses to the relative amount of light intercepted by the plants (as estimated from plant structural traits) up to these optimum light transmittance levels and diverged to lower values thereafter. These stable relationships suggest that the differences in plant growth at low and moderate light transmittance levels can be attributed to restrictions of photosynthesis by light availability. The reduction in growth for higher light transmittance levels may be partly attributed to photoinhibition as suggested by reduced chlorophyll content and relatively low increments in carotenoid content in leaves at high light transmittance levels.     

南疆灌耕棕漠土的基层分类

本文分析了南疆西部莎车县和东部哈密县灌耕棕漠土的成土条件,探讨了灌耕棕漠土的系统分类,特别是基层分类,根据南疆灌耕棕漠土的实际情况,结合11个剖面,讨论了土族和土系的划分依据和指标,描述了各土系的生产特性。     

A genetic fingerprinting test for identifying carcasses of protected deer species in China

State governments in China have laid down laws for protecting rare and endangered species. This study develops a genetic test using ‘southern hybridization’ to identify carcases of Chinese water deer (Hydropotes inermis Swinhoe) to provide forensic evidence of poaching. The method uses pta₂ oligonucleotide probe, which is quite distinct from PCR amplification and sequencing of Cytb gene or ribosomal sequences. It could be extended to identify other species of protected deer.     

湘西州猕猴桃产业品牌建设研究

实施品牌建设是猕猴桃产业发展的必然选择。本文从多方面分析了湘西州猕猴桃产业品牌建设现状及存在的问题,提出今后品牌建设的策略,以期对其品牌建设有一定的促进作用。     

Interactions between past land use, life-history traits and understory spatial heterogeneity

Past land use has contributed to variability in the distribution of herbaceous species by reducing plant abundance and altering species’ chances of recolonizing suitable habitat. Land use may also influence plant heterogeneity by changing environmental conditions within stands. We compared the variability of understory herb abundance in southern Appalachian forests with different land-use histories to examine how past land use influenced plant heterogeneity. The cover of eleven focal species or genera was estimated and mineral soil concentrations were determined during 2001 and 2002 in eight stands that were farmed, logged, or had no disturbance history (reference) in western North Carolina. Analysis of the coefficients of variation revealed that the abundance of understory plants was more heterogeneous in disturbed stands compared with reference stands. However, when nutrient availability differences were accounted for by detrending the plant cover data, understory variability within stands declined, and no differences between disturbed and reference stands could be distinguished. This finding suggests that nutrient availability has important effects on plant heterogeneity, which depend on past land use. Species dispersal, seed size, and phenology also explained variability in the spatial heterogeneity of plants, but generally only before soil nutrient differences were statistically controlled. In addition to demonstrating that past land use has long-term effects on plant heterogeneity, these results indicate that soil nutrients may play different roles in determining vegetation patterns in historically altered and unaltered forests.     

Southern bean Mosaic Virus the Causal Agent of a New Disease of Phaseolus vulgaris beans in Spain

Southern bean mosaic virus (SBMV) has been identified as the cause of a new disease in greenhouse-cultivated common bean (Phaseolus vulgaris), in the south-east of Spain. The identification was based on host range comparisons, morphological and serological characteristics of the virus, the size of its dsRNA species and the nucleotide sequence of an 810-bp fragment from ORF2. The virus could be clearly discriminated from the related sobemovirus Southern cowpea mosaic virus. This is the first report of SBMV in Spain.     

民国苏南地区蚕丝统制与生产改进

苏南各县虽然早有栽桑养蚕的历史,但是大规模的蚕桑养植还是开始于近代。无锡丝茧始于清初,其源肇自滨湖一带。(1)武进县也是在光绪初年才开始养蚕最初发轫与旧阳湖之安尚乡、横林镇等地方。(2)常州、     

南方林区野生林用绿肥的筛选研究

通过南方林区大量天然林及人工林的植被调查 ,从丰富的野生植物资源中筛选出适应林地生长并具较好水土保持及改良地力效果的林用绿肥 ,值得南方林区大力研究推广应用