西南岩溶地区石漠化综合治理研究

我国西南岩溶地区石漠化是人地矛盾作用下生态系统退化的过程或结果,石漠化不仅带来水土流失加剧、旱涝灾害频发、生物多样性降低等生态问题,还会带来贫困落后等一系列社会问题。20世纪80年代开始进行的石漠化治理工作已经成为我国西南岩溶地区生态文明建设的重要举措与必由之路,通过近40年来的石漠化治理使得我国西南岩溶地区石漠化问题恶化的趋势开始得到扭转。面向生态文明新时期的建设目标,石漠化脆弱区仍存在人地矛盾难以全面消除、治理成果可持续性亟待提升等问题,石漠化防治需要从多年来石漠化治理研究与实践探索积累中汲取有益于促进人地和谐、提升生态系统可持续性的治理经验与做法。因此,本文以石漠化治理典型区域调研资料与文献资料为数据基础,从石漠化治理目标、技术、措施和模式四个层面梳理石漠化治理经验与做法,归纳总结出石漠化综合治理四点配置原则:(1)以治理目标与预期周期为导向,确立石漠化治理采取的措施;(2)针对解决的关键生态退化问题,结合区域特征遴选石漠化治理技术;(3)针对石漠化退化阶段的差异,确定石漠化治理途径措施;(4)结合石漠化综合治理模式的共性特征,以小流域为基本单元,因地制宜的选择与构建石漠化综合治理模式。以期通过对实践经验的总结为石漠化治理过程中选择具备区位适宜性和机理明晰性的生态技术提供参考。     

Neuronal labeling patterns in the spinal cord of adult transgenic Zebrafish

We describe neuronal patterns in the spinal cord of adult zebrafish. We studied the distribution of cells and processes in the three spinal regions reported in the literature: the 8th vertebra used as a transection injury site, the 15th vertebra mainly used for motor cell recordings and also for crush injury, and the 24th vertebra used to record motor nerve activity. We used well‐known transgenic lines in which expression of green fluorescent protein (GFP) is driven by promoters to hb9 and isl1 in motoneurons, alx/chx10 and evx1 interneurons, ngn1 in sensory neurons and olig2 in oligodendrocytes, as well as antibodies for neurons (HuC/D, NF and SV2) and glia (GFAP). In isl1:GFP fish, GFP‐positive processes are retained in the upper part of ventral horns and two subsets of cell bodies are observed. The pattern of the transgene in hb9:GFP adults is more diffuse and fibers are present broadly through the adult spinal cord. In alx/chx10 and evx1 lines we respectively observed two and three different GFP‐positive populations. Finally, the ngn1:GFP transgene identifies dorsal root ganglion and some cells in dorsal horns. Interestingly some GFP positive fibers in ngn1:GFP fish are located around Mauthner axons and their density seems to be related to a rostrocaudal gradient. Many other cell types have been described in embryos and need to be studied in adults. Our findings provide a reference for further studies on spinal cytoarchitecture. Combined with physiological, histological and pathological/traumatic approaches, these studies will help clarify the operation of spinal locomotor circuits of adult zebrafish. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 642–660, 2016     

重引入狗獾秋冬季行为的初步研究

2010年11月至2011年2月在上海奉贤申亚生态园内,对从山东重引入的狗獾(Meles meles)在围栏内进行了秋冬季行为的初步研究。结果表明,重引入狗獾在冬季活动时间低,取食食物以肉类饲料为主,平均2～4 d出洞活动一次,受温度影响大。研究表明,重引入狗獾能适应人工饲养并顺利越冬。     

Regional environments, life-history patterns, and habitat use of spirostreptid millipedes in arid regions

Among diplopods with desert populations, only three species of Spirostreptida have been studied in an ecological context. The present review compares regional environments, life-history patterns, and uses of habitat by Orlhoporus ornatus (Girard) from southwestern North America, Archispirostreptus tumuliporus judaicus (Attems) from the eastern Mediterranean seaboard, and Harpagophora nigra (Attems) from southwestern Africa. Published and unpublished studies are used to explore evidence for convergence among these species, as opposed to traits adapting them to physical aspects of given regions or habitats. Unlike A. t. judaicus, O. ornatus and H. nigra are relatively restricted to arid habitats, although populations of all three species experience a variety of rainfall regimes and regional topographies. Where studied, O. ornatus and H. nigra hibernate during the long, often cool or cold dry season; they forage following warm-season rains. A. t. judaicus , in contrast, forages during its long, warm dry season and hibernates in the cool, wet winter. Populations from the Judaean and Negev deserts differ from those inhabiting a mesic habitat (Megiddo) closer to the coast in regard to rates of development, seasonal activity and seasonal water balance. Convergence in the form of well-developed desiccation resistance characterizes the two strictly desert species. All three species, together with other subtropical millipedes exposed to long dry seasons, are convergent with respect to patterns of diel surface activity and use of shelter. However species- and habitat-specific life-history features such as the seasonal timing of dormancy and emergence tend to mask convergence at the habitat level. Hence, the independent evolution of the three species with desert populations has resulted in life histories and habitat use that combine a moderate amount of convergence with considerable opportunistic adaptation to regional and local conditions.     

重庆岩溶区土壤景观多样性

不同土壤发生类型塑造了异质的景观格局,而土壤类型上不同的土地利用实践又对原有景观格局进行重构。研究的目的是利用景观指数识别重庆岩溶区土壤多样性的景观特征。结果表明：重庆市岩溶区土壤景观多样化和空间异质化程度不高,各景观分布比例不均匀;土壤景观嵌块体呈现复杂的几何形状,黄壤、石灰土和黄棕壤是主要的土壤类型;除山地草甸土以林地和草地,棕壤以林地为主要景观外,其余9种土壤类型都以耕地和林地为主要景观;农、林用地在重庆岩溶区土壤景观空间格局的结构和功能中起主导作用;但因各类土壤性质和分布特点的不同,耕地和林地在各类土壤上的分配比例上存在明显差异;人类活动在诱导耕地嵌块体数急剧增多的同时,居民工矿用地、林地、未利用地嵌块体数目也相应增加;研究可为岩溶区土地利用决策与调控提供科学依据,加深人们对岩溶区土壤多样性的理解。     

'Universal' microstructural patterns in cortical and trabecular, extracellular and extravascular bone materials: micromechanics-based prediction of anisotropic elasticity

Bone materials are characterized by an astonishing variability and diversity. Still, because of 'architectural constraints' due to once chosen material constituents and their physical interaction, the fundamental hierarchical organization or basic building plans of bone materials remain largely unchanged during biological evolution. Such universal patterns of microstructural organization govern the mechanical interaction of the elementary components of bone (hydroxyapatite, collagen, water; with directly measurable tissue-independent elastic properties), which are here quantified through a multiscale homogenization scheme delivering effective elastic properties of bone materials: at a scale of 10nm, long cylindrical collagen molecules, attached to each other at their ends by approximately 1.5nm long crosslinks and hosting intermolecular water inbetween, form a contiguous matrix called wet collagen. At a scale of several hundred nanometers, wet collagen and mineral crystal agglomerations interpenetrate each other, forming the mineralized fibril. At a scale of 5-10microm, the extracellular solid bone matrix is represented as collagen fibril inclusions embedded in a foam of largely disordered (extrafibrillar) mineral crystals. At a scale above the ultrastructure, where lacunae are embedded in extracellular bone matrix, the extravascular bone material is observed. Model estimates predicted from tissue-specific composition data gained from a multitude of chemical and physical tests agree remarkably well with corresponding acoustic stiffness experiments across a variety of cortical and trabecular, extracellular and extravascular materials. Besides from reconciling the well-documented, seemingly opposed concepts of 'mineral-reinforced collagen matrix' and 'collagen-reinforced mineral matrix' for bone ultrastructure, this approach opens new possibilities in the exploitation of computer tomographic data for nano-to-macro mechanics of bone organs.     

Competition,predation and flow rate as mediators of direct and indirect effects in a stream food chain

Using semi-natural stream channels, we estimated the effects of competition and predation exerted by juvenile and adult exotic rainbow trout (Oncorhynchus mykiss) on the diel activity pattern of juvenile native Atlantic salmon (Salmo salar), a secondary consumer. We also evaluated the direct and indirect effects of competition, predation and abiotic factors (water depth and velocity) on the growth rate of salmon, the biomass of invertebrate grazers (primary consumers) and the biomass of periphytic algae (primary producers; chlorophyll a). The presence of chemical cues emanating from adult predatory trout reduced the daily activity of juvenile Atlantic salmon. In contrast, competition imposed by juvenile rainbow trout forced Atlantic salmon to be more active during the day, even if adult rainbow trout were also present. We found no effect of either competition or of predatory cues on the growth rate of Atlantic salmon, and no evidence of indirect effects on either the biomass of invertebrates or the biomass of chlorophyll a. In contrast, we demonstrated that this food chain (fish--invertebrate grazers--periphytic algae) was under the control of a critical abiotic factor, the water velocity, and of bottom-up processes. We concluded that the exotic species directly increases the risk of predation of the native Atlantic salmon, but behavioral compensation probably limits the effects on growth rate. The competition and predation imposed by the invaders had no indirect effects on lower trophic levels. Top-down effects may have been mitigated by the dominant influence of water velocity controlling all components of the food chain and by elevated levels of primary production.     

Robustness of the biotic indicators used for classification of ecological status of lotic water bodies: A testing method when the data series are short

Successful implementation of the Water Framework Directive and achieving its objective of good ecological status of all water bodies depend on the power of the set of monitoring indicators to capture the change in the ecological status of aquatic systems. In this context, testing the robustness and sensitivity of ecological indicators currently used for assessing the status of lotic water bodies is instrumental for the adaptation and further development of assessment methods. This is also a prerequisite for an effective, context-based monitoring system and for improving the quality of the decision making for water bodies. This is particularly challenging in regions where the sets of indicators are under development, the data series are relatively short and data which addresses the individual error sources are lacking. Here we show that hierarchical clusters and ordination analysis provide appropriate tools with which the validity of the ecological status of water bodies set up based on biological multimetric monitoring indices in a small water basin could be tested. We hypothesize that robust and informative monitoring methods classify all water bodies belonging to a single ordination grouping in the same quality class (high, good, moderate, poor or bad). In our case study multimetric biological indicators failed to discriminate between the good and moderate ecological status. Community structure as well as water conductivity and nitrate load were primarily responsible for the observed difference between ordination groupings. Inconsistencies shown in our case study are likely to be induced by insufficient refinement of monitoring schemes and by the constraints existing in the data series and available metadata. We show that multiplication of indicators leads to discrepant interpretation and problematic application. Proposed ordination analysis proves to be a simple and useful tool to detect such discrepancies and support further progress in indicator development. Integrated and longer data and metadata series are needed to refine context-based monitoring methods.     

Effects of temporary closure of a national park on leopard movement and behaviour in tropical Asia

Across Asia protected areas serve as refuges for carnivores inside human-dominated landscapes. However, the creation of hard edges around reserve boundaries where conflicts with humans arise and disturbance from human activities inside the reserves may affect carnivore behaviour and ecology. Thailand’s largest protected area, Kaeng Krachan National Park (2915 km²) receives >100,000 visitors annually while maintaining an intact assemblage of prey species for large carnivores, making it a potentially important site for population recovery of leopards (Panthera pardus), tigers (Panthera tigris) and dholes (Cuon alpinus). We assessed the abundance of leopards and their prey base, and their response to changes in levels of human activity after an unexpected flooding event that resulted in the park being closed to visitors for >6 months. Using camera-traps, we identified 6 individual leopards and used spatially explicit capture-recapture (SECR) methods, incorporating humans and prey as covariates, to test for factors affecting the detection probability of leopards before and after the park closure. Leopard density was unchanged between the two periods, however the movement and activity patterns were clearly different. In the absence of tourist activity, leopards tended to move more frequently, leopard detection rates increased by 70% and activity shifted towards being more diurnal. The consequences of these changes in behaviour may include improved health, reproduction and survival. A management strategy involving seasonal closure of parks may serve to alleviate pressure on leopards and other carnivores. We recommend using information on abundance of large carnivores and their prey species, and human disturbance as the key indicators for long-term monitoring and management of protected areas in Southeast Asia.