Participatory selection process for indicators of rangeland condition in the Kalahari

To develop indicator–based management tools that can facilitate sustainable natural resource management by non–specialists, meaningful participation of stakeholders is essential. A participatory framework is proposed for the identification, evaluation and selection of rangeland condition indicators. This framework is applied to the assessment of rangeland degradation processes and sustainable natural resource management with pastoralists in the southern Kalahari, Botswana. Farmer knowledge focused on vegetation and livestock, with soil, wild animal and socio–economic indicators playing a lesser role. Most were indicators of current rangeland condition; however 'early warning' indicators were also identified by some key informants. This demonstrates that some local knowledge is process–based. Such knowledge could be used to improve indicator–based management tools and extension advice on the livelihood adaptations necessary to prevent or reduce ecological change, capable of threatening livelihood sustainability. There is evidence that social background influences indicator use. Communal farmers rely most heavily on vegetation and livestock indicators, whilst syndicate and land–owning pastoralists cite wild animal and soil–based indicators most frequently. These factors must be considered if indicator–based management tools are to meet the requirements of a diverse community.     

拉萨市空气含氧量变化研究

对拉萨市空气含氧量进行了研究,分析了该值的日变化、逐日变化,并结合气象因子分析了可能导致该变化的原因。结果表明:拉萨市含氧量一天内有明显的峰值和谷值;含氧量变化与相对湿度显著负相关,与温度、气压不能通过相关性检验;与海平面地区含氧量相比,拉萨市含氧量变化不大;含氧量与每立方米空气中氧气的质量没有直接关系,不能用来衡量空气中氧气的绝对含量。     

东昆仑东段杨树沟金矿地质特征及找矿方向

杨树沟金矿位于东昆仑成矿省伯喀里克-香日德印支期金、铅、锌、铁、石墨（铜、稀有、稀土）成矿带的东段.矿体严格受近东西向、北东向断裂构造控制.成矿类型为构造蚀变岩型金矿床,成矿时代为印支早期.矿区中已发现的金矿带深部及矿区东南部断裂发育地区具有较好的找矿空间,下一步工作应针对含矿构造破碎带,采用探矿工程与化探工作相结合等手段开展矿区东南部及深部找矿工作,寻找金矿体,争取该矿区找矿的更大突破.     

On geostrophic reference levels in the Bering Sea basin

Various data sets in the deep Bering Sea are examined in an effort to find suitable reference levels for geostrophic transport computations. Because of the lack of other data, classical methods are used: mainly vertical structure of differences in geopotential (method of Defant) and mass conservation. In the western Bering Sea, maximum transports are usually, but not always, obtained by using reference levels near the bottom. In the central region, there is considerable variability, both spatial and temporal, in the depth of the most suitable reference level, which varies from 500 to at least 1500 db. The variations seem to be related to depth of inflow in the passes, to near-surface salinity gradients, and to features such as upward movement of water or well-developed eddies.     

Community ecology of the metazoan parasites of snoek Thyrsites atun (Euphrasen, 1791) (Perciformes: Gempylidae) off South Africa

The parasite assemblage of snoek Thyrsites atun, a commercially important fish in the Benguela system, was examined over a one-year period. In all, 16 parasite taxa including eight new host records (Bolbosoma vasculosum, Caligus coryphaenae, Caligus dakari, Corynosoma australe, Hatschekia conifera, Nothobomolochus fradei, Rhadinorhynchus cadenati, Tentacularia coryphaenae) and four new locality records (B. vasculosum, C. dakari, Molicola uncinatus, Pseudoterranova sp.) were recovered from 210 specimens. The dominance of larval helminths in the component community suggests that T. atun occupies an intermediate position in the food web. The ‘nestedness metric based on overlap and decreasing fill’ (NODF) indicated that the parasite assemblage exhibited no nestedness (NODF = 73.3, p = 0.103). Generalised additive mixed modelling results indicated that host length is the main determinant of parasite species richness in T. atun. PERMANOVA and ANOSIM suggested that infracommunity structure varied little with respect to the sex, length, seasonality and capture region of the host. The stability and randomness in parasite acquisition, as indicated by the lack of nestedness of the parasite assemblage, can be ascribed to the opportunistic feeding behaviour and nomadic movement of T. atun in the southern Benguela. The homogeneity of the community structure of long-lived endoparasites suggests that a single T. atun stock occurs off South Africa.     

A computer-aided framework for subsurface identification of white shark pigment patterns

Subsurface video footage can be used as a successful identification tool for various marine organisms; however, processing of such information has proven challenging. This study tests the use of automated software to assist with photo-identification of the great white shark Carcharodon carcharias in the region of Gansbaai, on the south coast of South Africa. A subsurface photo catalogue was created from underwater video footage. Single individuals were identified by using pigmentation patterns. From this catalogue, two images of the head for each individual were inserted into automated contour-recognition software (Interactive Individual Identification System Beta Contour 3.0). One image was used to search the database, the other served as a reference image. Identification was made by means of a contour, assigned using the software to the irregular border of grey and white on the shark's head. In total, 90 different contours were processed. The output provided ranks, where the first match would be a direct identification of the individual. The method proved to be accurate, in particular for high-quality images where 88.24% and 94.12%, respectively, were identified by two independent analysts as first match, and with all individuals identified within the top 10 matches. The inclusion of metadata improved accuracy and precision, allowing identification of even low-quality images.     

Tectonic wedging along the rear of the offshore Taiwan accretionary prism

The structural geometry, kinematics and density structure along the rear of the offshore Taiwan accretionary prism were studied using seismic reflection profiling and gravity modeling. Deformation between the offshore prism and forearc basin at the point of incipient collision, and southward into the region of subduction, has been interpreted as a tectonic wedge, similar to those observed along the front of mountain ranges. This tectonic wedge is bounded by an east-dipping roof thrust and a blind, west-dipping floor thrust. An east-dipping sequence of forearc-basin strata in the hanging wall of the roof thrust reaches a thickness in excess of 4 km near the tip of the interpreted tectonic wedge. Section restoration of the roof sequence yields an estimate of 4 km of shortening, which is small compared with that inferred in the collision area to the north, based on the variation in distance between the apex of the prism and the island arc.Previous studies propose that either high-angle normal faulting or backfolding has exhumed the metamorphic rocks along the eastern flank of the Central Range in the collision zone on land. To better constrain the initial crustal configuration, we tested 350 crustal models to fit the free-air gravity anomaly data in the offshore region to study the density structure along the rear of the accretionary prism in the subduction and initial collision zones before the structures become more complex in the collision zone on land. The gravity anomaly, observed in the region of subduction (20.2°N), can be modeled with the arc basement forming a trenchward-dipping backstop that is overlain by materials with densities in the range of sedimentary rocks. Near the point of incipient collision (20.9°N), however, the free-air gravity anomaly over the rear of the prism is approximately 40 mgal higher, compared with the region of subduction, and requires a significant component of high density crustal rocks within the tectonic wedge. These results suggest that the forearc basement may be deformed along the rear of the prism, associated with the onset of collision, but not in the subduction region further to the south.     

1971—2006年珠穆朗玛峰地区蒸发皿蒸发量的变化及其影响因素

升温率略高于平均最高气温的升温率.珠峰地区日照时数和平均风速的显著下降,以及相对湿度的明显增加可能是蒸发皿蒸发量下降的主要原因.     

Biodiversity,land degradation,and climate change: Participatory planning in Romania

This paper considers the role of stakeholder participation in drawing together the three Rio Conventions, exploring how participatory activities to combat desertification in southern Romania can both support and hinder efforts to conserve biodiversity and mitigate the effects of climate change. It suggests that Romania's growing civil society sector has a potentially vital role to play in promoting synergy through participation, and that participatory processes act as an important mechanism for harnessing multiple benefits. The paper argues that participation needs to be further institutionalised within the Romanian context and in doing so, should emphasise empowerment, equity, trust and learning, integrating different knowledge bases to allow the development of sustainable and synergistic environmental solutions.