Conservation and utilisation of South Coast renosterveld,an endangered South African vegetation type

South Coast Renosterveld is a small-leaved shrubland confined to the semi-arid and sub-humid coastal forelands of the southern and south-eastern Cape, South Africa. The flora of this vegetation type is biogeographically complex and includes numerous local endemics, many of which are geophytes. Much of the renosterveld is being converted to cereals and artificial pastures; conservation status is critical. There is evidence that the renosterveld has been derived in historical times from a Themeda triandra-dominated grassland. It is suggested that the reestablishment of a vigorous grassy sward would be the most effective long-term conservation strategy since utilisation would be compatible with conservation. Management models to improve the grazing status of South Coast Renosterveld should consider the biological attributes of key species. On the basis of phenological and other life history data on the dominant undesirable shrub (Elytropappus rhinocerotis, Metalasia muricata) and desirable grass (Themeda triandra) species, autumn is considered the optimum season of burn for the re-establishment of grassland.     

Integrating farming and wildlife conservation: the Barnacle Goose Management Scheme

Since 1994 the Barnacle Goose Management Scheme (BGMS) has integrated conservation and agricultural aims on the Scottish side of the Solway Firth. In the 4 years before the introduction of the BGMS, the density of barnacle geese (Branta leucopsis) on the Wildfowl & Wetlands Trust Reserve at Caerlaverock was four times higher than on the non-Reserve area. In the 6 years following establishment of the BGMS, the density of geese on non-Reserve fields rose so that the Reserve had twice the density of the non-Reserve area. No difference in density was found between fields in the Feeding Zone and Intermediate Zone of the BGMS. The density of barnacle geese around the study area appears to be at a maximum under current management regimes. The remaining geese from this increasing population are using other feeding areas. This may lead to further conservation-agriculture conflict in the future, but could be mitigated through expanding the range and quality of the BGMS, through increasing the dedicated reserve network, or through a combination of the two.     

The use of the Solway Firth,Britain, by barnacle geese Branta leucopsis Bechst. in relation to refuge establishment and increases in numbers

This paper analyses data on movements and distribution of barnacle geese Branta leucopsis over a period of 15 years to examine the influence of the enlargement of a disturbance-free refuge at Caerlaverock on the Solway Firth on the numbers, distribution and feeding habits of the geese. The Solway barnacle geese form the whole of the discrete population breeding in the Svalbard (Spitsbergen) archipelago.The use of the refuge by geese increased markedly following its establishment, and a high proportion of the birds were accomodated there, especially in early winter. As the population increased, however, (from 3200 in 1970 to 10 500 in 1984), the geese dispersed in greater numbers to other habitats within the Caerlaverock area and elsewhere on the Solway. The creation of the new refuge has been, as was the declaration of the National Nature Reserve in 1957, responsible for the increase in numbers through reducing annual mortality rate, much of which was due to illegal shooting.The most significant change in distribution was the increase in the use of arable grassland in spring and this was attributed to the semi-natural saltmarsh at Rockcliffe, the traditional spring haunt, reaching capacity. The use of stubble grain also increased, but its availability is sporadic due to variation in late summer weather.The creation and management of the refuge achieved the objectives of redistributing the geese and allowing numbers to increase. It was also, at least partly, responsible for bringing about changes in feeding habits. This analysis has demonstrated that if the impacts of refuge establishment are to be fully understood, studies must be detailed and must include areas outside the refuge itself and its immediate environs.Detailed concurrent investigations on the dynamics of this population indicate that the slowing down of growth in numbers is due to some limitation on the breeding grounds. Continued monitoring and sensitive management over the whole of the winter range are essential not only to ensure the well-being of the population but also to minimise the conflict between the geese and farmers. Detailed investigations of possible changes in the saltmarsh habitat are also urgently needed.     

Influence of connectivity, habitat quality and invasive species on egg and larval distributions and local abundance of crucian carp in Japanese agricultural landscapes

The quality of habitat at and around a spawning site, and the availability of movement between spawning and nonspawning habitats are likely to be important determinants for population persistence in a degraded and fragmented landscape. We assessed the influence of habitat connectivity, habitat quality and invasive species for distributions and local abundance of eggs and larvae of crucian carp (Crassius auratus complex, which is listed as “data deficient” on the Japanese Red List) in agricultural landscapes surrounding Lake Mikata, Japan, where drainage ditches and paddy fields are extensively utilised for spawning (lake or river shores are also used). We investigated the presence and abundance of eggs and larvae of crucian carp and habitat components at 146 sites across a range of presumed spawning habitats. Egg presence was affected strongly by connectivity to the lake (watercourse distance from the lake), and egg abundance was significantly influenced by both connectivity and habitat quality. In contrast, larval presence was primarily related to habitat quality. Larval abundance was influenced by connectivity and habitat quality, but the effect of connectivity was relatively low. Furthermore, larval abundance was negatively related to the presence of the invasive species red swamp crayfish (Procambarus craki) and bullfrog (Rana catesbeiana). Our findings indicate that connectivity, habitat quality and the presences of invasive species are crucial in determining suitable spawning and nursery habitats, but their relative importance may vary depending on egg and larval life stages. We suggest that restoring connectivity, improving habitat quality and removal of invasive species could be effective conservation strategies for the declining populations of crucian carp in agricultural landscapes.     

泾河流域水土保持生态环境建设与治理方略刍议

根据水利部第二期黄河水沙变化研究基金项目"泾河流域水土保持措施减水减沙作用分析"研究成果指出:水土保持综合治理依然是泾河流域生态环境建设的根本.泾河流域水土保持工作应该坚持水保立县,因地制宜,防治结合,强化管理,坚决制止人为新增水土流失,才能为流域国民经济和社会的可持续发展提供有力的生态保证和良好的生态环境,才能使青山常在,绿水长流,最终实现"山川秀美"的宏伟目标.     

Satellite tracking of breeding black storks Ciconia nigra: new incomes for spatial conservation issues

Satellite tracking of black storks was used to estimate home range sizes and to study habitat selection during the breeding season. Breeding and non-breeding adults foraged over very large areas (ca. 54 000 ha for 12 territories), preferentially in woodlands with high number of river sources, mirroring the species needs for high quality water resource. Rearing and post-fledging ranges of breeding partners largely overlapped. Home ranges of non-breeding adults largely overlapped ranges of breeding birds, so that assessing home range size of breeding pairs from observed densities is not reliable. Protection and management of breeding and feeding habitats appear to be the most important conservation measures to be considered. This study allowed to evaluate how large these protected areas should be, and which habitat types they should encompass. Conservation measures for the species in western Europe should include protection of very large forest areas and also focus on managing river networks to ensure a high water quality as far as 20 km away from nests.     

Designing protected areas to conserve riverine biodiversity: Lessons from a hypothetical redesign of the Kruger National Park

The process of designing protected areas to represent all ecosystems in an area adequately is becoming increasingly sophisticated. To date freshwater aquatic ecosystems have seldom been considered in this process. How much of a difference does it make when they are considered as well?This study examined the conservation of riverine biodiversity within 17 assessment units contained by the catchment areas of five perennial rivers flowing through Kruger National Park and two seasonal rivers that are largely contained within this park. Physical river types, fish species and invertebrate families or genera were used as surrogates of riverine biodiversity. Conservation planning software was used to select an optimal set of planning units to represent and maintain riverine biodiversity.The current spatial configuration of Kruger National Park, largely an accident of history, is particularly poor when assessed against the objective of conserving riverine biodiversity. Several alternative layouts are examined. These options are theoretical since there is little current opportunity to reassign land uses in the region. This study shows that substantially improved layouts for both riverine and terrestrial biodiversity are possible, under the constraint of the same total area under protection. The study also shows that even these optimal layouts are only partially successful in efforts to conserve fully representative samples of riverine biodiversity. Because of the longitudinal connectivity of rivers, conservation strategies that extend beyond protected areas are essential. Explicit conservation visions, targets and strategies need to be included in integrated water resource management plans.Based on the results of this study, nine recommendations are provided for increasing the effectiveness of current and future protected areas in conserving riverine biodiversity. These are to use systematic conservation planning to make biodiversity benefits explicit; mend the disconnect between terrestrial and freshwater conservation; use multiple surrogates wherever possible; be strategic about the collection and management of primary data; strive for maximum hydrologic connectivity; resist development pressure; foster good relationships across park fences; where relevant, pursue multi-national cooperation at the basin scale; and engage the value debate and resolve awareness and capacity constraints.     

海河流域水土保持生态用水研究

 为确定海河流域不同类型区水土保持综合治理的减水减沙作用,并为估算生态用水提供依据,采用定性与定量相结合的方法,划分海河流域生态环境建设区;在分区的基础上,根据多年来小流域治理减水减沙作用的观测成果,分析、计算黄土丘陵沟壑区、土石山区、石质山区的减水减沙定额;以各分区水土流失综合治理的保存面积及规划治理面积为依据,计算出海河流域现状、2010年及2030年的水土保持生态用水分别为26.06亿、42.92亿及71.53亿m3。     

Conservation of highly fragmented systems: The north temperate Alexander Archipelago

The Alexander Archipelago of Southeast Alaska encompasses over 2000 named islands that extend along 600 km of the North Pacific Coast. This review summarizes recent research on mammals of this largely unexplored region. Field inventories followed by preliminary molecular genetic analyses of selected mammals demonstrate substantial spatial structure consistent with both the dynamic geologic history of this boreal region and the highly insular landscape. New views of taxonomic diversity, biogeographic history, and contemporary population connectivity lay a framework for managing and conserving this complex biome. First, repeated Pleistocene glacial advances along the coast fragmented species, leaving clear genetic signatures and a strongly diversified fauna. Organisms recolonized the coast following deglaciation from multiple northern (Beringia), southern (West Coast and Continental) or North Pacific Coastal refugia. Several species are composed of multiple, genetically distinctive lineages (in some cases, incipient or new species) due to independent colonization histories from distinct, divergent source populations. Second, the insular landscape of the Alexander Archipelago has produced highly endemic populations. These centers of endemism should be thoughtfully managed as hotspots of lineage diversity. Until a better understanding of connectivity among these divergent populations is developed, each island should be considered an independent biological unit. Finally, industrial logging, mining, human encroachment, tourism, wildlife consumption, and invasive species should be stringently monitored and regulated with respect to impact on island endemics and ecosystems. A new conservation paradigm for the Tongass National Forest should be developed that is built around the recognition of the complexity of this incomparable island archipelago of the North Pacific. In particular, recognition of high diversity and endemism should be central to management plans.     

美国大流域长时间序列水土保持减沙效果分析

 为借鉴美国开发治理比较早的一些河流的经验教训,选择密苏里河上游的Willow、佐治亚州LloydShoals水库、韦科、田纳西河一级支流渡科河、科罗拉多河上游等5条较大的流域进行水土保持减沙效果分析。通过前后长达1032年的大流域、长时间序列的水土流失治理,在排除降雨和水利工程影响的因素,其下游河道减沙效果都很显著,减沙分别在38%～55%之间。     

景观生态学在河流生态修复中的应用

景观生态学强调景观的时空变化,非常适于评价和定量描述河流的变化,已被广泛用来管理和修复河流生态系统,对我国大规模的水土保持生态环境建设将产生深远而重要的影响。基于景观生态学的预案方法是生态修复的有效工具。     

不同类型水源保护林水资源保护功能的分析和评价

针对北京市密云县密云水库上游清水河流域现有水源保护林类型现状,对油松林、刺槐林、板栗林及混交林4个林分类型的截留降雨、枯枝落叶容纳雨量、林地土壤蓄水、减少地表径流及净化水质能力进行了分析、比较和评价。结果表明,在最小消耗水资源和有利于水资源积累的前提下,水源保护林中的油松水资源消耗较少,混交林次之,刺槐林、板栗林最多。因此建议水源保护林营造应加大耗水能力小和净化水质的树种比例。     

石亭江洪灾成因与治理对策浅议

从石亭江水灾泛滥引发思考,寻找原因,认为人为水土流失是诱发水灾的重要原因,指出水土保持的重要性及实施可持续发展战略的必然性.     

Options for liming rivers to ameliorate acidity — A UK perspective

The options for large scale liming of river systems are reviewed with particular reference to the River Tywi in Wales, a major salmonid river with a reservoir in the upper catchment. For hydrological source area liming the cost of lime transport is high due to remoteness and inaccessibility. The concern of potential damage to wetland mires of conservation value is considered. Re-treatment intervals are expected to be 5–10 years, but results from sub-catchment experiments indicate that treatment longevity and the pattern of ecological recovery are uncertain. Flow-related dosing systems for rivers avoid impacts on wetlands but would treat only the main river. Reliability may be problematical though the reservoir provides a margin of safety against system failure. Reservoirs can be limed to treat the main river outflow. This avoids the problems of power supply. For the River Tywi, the financial costs of both direct treatment methods are lower than for catchment liming and comparable with estimates of the economic benefit to the fishery. The system currently operated on the Tywi is reservoir treatment. Results from the first 3 years demonstrate colonization of the main river by acid intolerant invertebrate taxa and clear increases in populations of juvenile Atlantic salmon, Salmo salar L. and sea/brown trout. Salmo trutta L.     

妫水河流域水源涵养林时空动态格局研究

 分析官厅水库上游妫水河流域20多年水源涵养林分布格局的动态变化。结果表明:妫水河流域的森林覆盖率一直呈上升状态,从1975年的10.96%,已上升到46.61%;经济林面积增长迅速,每年约增长150hm2;树种组成正在向多样性转化,从1975年以4个主要树种为主,到1995年已形成8个树种的格局。因此认为妫水河流域水源涵养林总体状况正在好转,但还存在经济林面积增加过快,可能引起环境污染和森林植被类型结构不合理等问题。     

我国水土保持的目标与任务

 我国是世界上水土流失最为严重的国家之一。近几年来,我国水土保持生态建设取得了显著成效,7大流域水土保持重点工程建设扎实推进;生态修复工程广泛展开;水保监督执法继续深入;人为水土流失得到遏止;水土保持科学研究取得了重大进展。新形势下,我国水土保持工作的思路是,紧紧围绕治理水土流失、改善农业生产条件和生态环境3大目标,认真落实预防监督、综合治理、生态修复、监测预报4项任务,采取行政、经济、法律等多种措施,促进水土资源可持续利用,维系良好生态环境,为全面建设小康社会提供支撑和保障。     

中山市平原河网区水土流失易发区划分研究

[目的]开展中山市境内平原河网区水土流失易发区的划分工作,为更好地贯彻落实《水土保持法》,保护宝贵的水土资源,为政府依法行政、实施生产建设项目水土保持管理提供科学依据。[方法]通过分析区域内土壤抗蚀性弱,母岩易风化,降水多,强度大且年内分布不均,水热条件充裕等自然特点,以及人类社会经济活动较强等社会经济特点,基于GIS,RS技术开展研究。[结果]通过划分水土保持分区,明确了需界定水土流失易发区的平原河网区范围,也探明了研究区地形地貌、降雨、土壤、植被及河网区水土流失易发敏感因子,合理选取定量和定性指标,构建了水土流失易发区划分指标体系,划分出中山市平原河网区水土流失易发区。[结论]中山市平原河网区水土流失易发区主要有小榄镇、黄圃镇等9个镇区,土地面积约666.92km2,占该市土地总面积的37.39%。易发区划分成果完善了中山市水土保持规划体系,同时也可为编制地市级水土保持规划或制定规章制度提供依据。     

In Situ Avoidance Response Of Adult Atlantic Salmon To Waste From The Wood Pulp Industry

An accidental release of non-toxic waste from decommissioned wood pulp industry in the River Numedalslågen, Southern Norway, occurred in the upper part of the accessible stretches for anadromous fish during a study of migration behaviour of radio tagged Atlantic salmon (Salmo salar, n=32, body length 51–99 cm). The fish had completed the migration phase and initiated the resident phase characterised by little movement until spawning. When the wooden fibres and pulp were released, 16 of 32 (50%) salmon showed an immediate avoidance response. Six (19%) salmon moved upstream and 10 (31%) salmon moved downstream. Of the salmon moving downstream, eight (25%) moved all the way to sea (average 14.8 km). Four re-entered the River Numedalslågen, two entered a neighbouring river and two were not recorded later. Fish moving downstream but without moving to the sea, moved on average 5.3 km during the episode, whereas those moving upstream moved on average 6.7 km. All fish recorded after the episode (n=30) survived until the spawning season. The study demonstrates that fish in nature may show an evident avoidance response, even to non-toxic contaminants. For Atlantic salmon, the size of the spawning population may be reduced by fish leaving the river (13% left the river and never came back). Moreover, the dispersal of salmon to other rivers may increase, and the distribution of the spawning population within the contaminated river may shift.     

红柳河流域库坝群的治理

分析了陕北红柳河流域库坝工程对该地区水土保持及减少入黄泥沙的显著作用,强调了工程措施在治理水土流失中的重要地位,并根据红柳河流域库坝群的现状,指出了存在的主要问题及其严重危害,提出必须加快红柳河流域库坝群的治理。     

辽宁省柳河上游重点治理的成就与经验

辽宁省柳河上游水土流失面积1034.78km~2,部分地区年土壤侵蚀模数高达10000t/km~2以上。严重的水土流失,导致上游群众生活贫困,下游河道泥沙淤积,使柳河成为地上悬河,洪水灾害频繁。该流域自1983年被列入全国水土流失重点治理区后,十年共完成水土保持综合治理措施保存面积579.87km~2,累计治理面积占水土流失面积的79％。经过重点治理,流域输沙量减少87％,森林覆盖率由17.4％提高到34.6％,粮食总产量提高2.5倍,人均收入增加4.57倍,收到显著的经济效益、生态效益和社会效益,并为组织大面积的综合治理积累了经验。