Towards a conceptual model of hydrological change on an abandoned cutover bog,Quebec     

Tim E. Van Seters  Jonathan S. Price 《水文研究》2002,16(10):1965-1981

Cutover bogs do not return to functional peatland ecosystems after abandonment because re‐establishment of peat‐forming mosses is poor. This paper presents a conceptual model of bog disturbance caused by peat harvesting (1942–1972), and the hydrological evolution that occurred after abandonment (1973–1998). Two adjacent bogs of similar size and origin, one harvested and the other essentially undisturbed, provide the basis for understanding what changes occurred. The model is based on historical trends evident from previous surveys of land‐use, bog ecology and resource mapping; and from recent hydrological and ecological data that characterize the current condition. Water balance data and historical information suggest that runoff increased and evapotranspiration decreased following drainage, but tended towards pre‐disturbance levels following abandonment, as vegetation recolonized the surface and drainage became less efficient over time. Dewatering of soil pores after drainage caused shrinkage and oxidation of the peat and surface subsidence of approximately 80 cm over 57 years. Comparisons with a nearby natural bog suggest that bulk density in the upper 50 cm of cutover peat increased from 0·07 to 0·13 g cm^?3, specific yield declined from 0·14 to 0·07, water table fluctuations were 67% greater, and mean saturated hydraulic conductivity declined from 4·1 × 10^?5 to 1·3 × 10^?5 cm s^?1. More than 25 years after abandonment, Sphagnum mosses were distributed over broad areas but covered less than 15% of the surface. Areas with ‘good’ Sphagnum regeneration (>10% cover) were strongly correlated with high water tables (mean ?22 cm), especially in zones of seasonal groundwater discharge, artefacts of the extraction history. Forest cover expanded from 5 to 20% of the study area following abandonment. The effect of forest growth (transpiration and interception) and drainage on lowering water levels eventually will be countered by slower water movement through the increasingly dense soil, and by natural ditch deterioration. However, without management intervention, full re‐establishment of natural hydrological functions will take a very long time. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Seed germination of seven Sahelian legume species     

A. Sy  M. Grouzis  P. Danthu   《Journal of Arid Environments》2001,49(4):875

As part of the restoration of degraded land south of the Sahara, an experimental study has been carried out on the germinative properties of the seeds of seven Sahelian leguminous species (Cassia obtusifolia, Cassia occidentalis, Indigofera astragalina, Indigofera senegalensis, Indigofera tinctoria, Sesbania pachycarpa and Tephrosia purpurea). Analysis of the effects of temperature, pretreatment and water potential has enabled definition of their optimum germination conditions. For the temperature range studied (20–40°C), germination capacity was significantly greater between 30 and 35°C for all species. All species except Cassia obtusifolia developed a very strong integumental inhibition which was easily eliminated by mechanical scarification or immersion in concentrated sulphuric acid (H₂SO₄, 95%). Study of the influence of water potential on germination showed that these species are able to germinate at relatively low water potentials. Different patterns of response to water stress are highlighted and explained by the different behaviours of these species in the semi-arid conditions of the Sahelian environment.  相似文献   

湿地恢复研究综述   总被引：113，自引：0，他引：113  

崔保山  刘兴土 《地球科学进展》1999,14(4):358-364

湿地恢复研究是当今恢复生态学研究的主要内容这一，从湿地恢复的基本概念入手，阐述了恢复与湿地恢复的基本内涵，简述了国内外湿地恢复研究的进展。以生态学原理为基础，分析了湿地恢复了３个基本原则，即可行性原则、稀缺性和优先性原则、美学原则。也阐述了湿地恢复的主要目标。从沼汉、河流及河缘湿地、湖泊出发，简述了湿地恢复的基本策略。文中还从生态、社会、经济相整合的角度剖析了湿地恢复的复合性问题。文章最后对湿地恢  相似文献   

Implementing the WSSD decision of restoring marine ecosystems by 2015—scientific information support in the public domain     

Cornelia E. Nauen 《Marine Policy》2006

Among the relatively few decisions taken by heads of States and government at the World Summit on Sustainable Development (WSSD) in September 2002 in Johannesburg, South Africa, was the time-bound objective to restore degraded stocks to productive levels in its Plan of Implementation. The paper examines the evidence leading to this decision and the broadening of cognitive maps it implies. In particular, it documents how public archiving of research results and other knowledge sources particularly those accessible through the FishBase (www.fishbase.org) and Sea Around Us (www.seaaroundus.org) websites has been effective in enabling citizens in addition to specialist publics to counteract shifting baselines and monitor progress against the WSSD plan. The increased targeting and cost-effectiveness of research efforts and the social benefits of public research spending this implies militates for the extension of such approaches to other groups as an enabling mechanism for WSSD decisions on restoring marine ecosystems by 2015.  相似文献   

Trialling tools using hand-weeding,weed mat and artificial shading to control nuisance macrophyte growth at multiple scales in small agricultural waterways     

Kathryn E. Collins  Catherine M. Febria  Hayley S. Devlin  Kristy L. Hogsden  Helen J. Warburton  Brandon C. Goeller 《新西兰海洋与淡水研究杂志》2020,54(3):512-526

ABSTRACT

Introduced aquatic macrophytes can dominate small agricultural waterways in summer and autumn becoming a significant management problem. Excessive growth can clog waterways, causing drainage issues and reducing agricultural productivity while in-stream velocities are reduced and sedimentation increased. Consequently, water managers remove them by mechanical clearance, chemical spray and cutting which can be costly and have negative impacts on in-stream habitat and ecological health. We trialled three tools to reduce macrophytes: hand-weeding, weed mat and artificial shading, at a reach-scale (50?m) and larger-scale (200–400?m). Hand-weeding reduced cover in the short-term, however macrophytes recovered to pre-treatment levels within one season. Weed mat along the banks was effective at reducing emergent macrophytes, particularly Erythranthe guttata (monkey musk) and Nasturtium microphyllum (watercress). Weed mat lasted for several growing seasons and continued to be effective. Shading over the waterway using polythene markedly reduced submerged macrophytes indicating that heavy shading by riparian plantings could reduce submerged macrophytes in the longer-term. These results indicate that in the short-term, weed mat could be used to limit sprawling emergent macrophytes. In the longer-term, weed mat used in conjunction with riparian planting could provide shading so that macrophyte cover in these small waterways could be reduced and controlled.  相似文献   

Management measures and fishers' commitment to sustainable exploitation: a case study of Atlantic salmon fisheries in the Baltic Sea     

Haapasaari  P.; Michielsens  C. G. J.; Karjalainen  T. P.; Reinikainen  K.; Kuikka  S. 《ICES Journal of Marine Science》2007,64(4):825-833

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塔里木河下游地下水抬升的地表植被恢复价值初探     

徐海量  叶茂  丁宇  张青青 《干旱区地理》2007,30(4):82-486

基于塔里木河下游生态输水前后地下水动态变化和地表植被响应的长期监测资料,以输水后地下水动态变化引起的地表植被生物量差异为出发点,借鉴国内外生态经济价值量化的计算方法,从地表植被响应的生态经济价值和地下水抬升的潜在恢复价值来计算生态输水后植被恢复的地表生态经济价值。目的是为量化生态输水工程的恢复效益提供理论依据。结果显示:在塔里木河下游典型的考干断面,垂直河道方向为长的2 000 m、平行河道方向为宽的100 m的样带内,地下水位出现了明显的抬升,水位抬升幅度以河道为中心由近到远逐渐降低,这点突出地反映在以柽柳灌丛为主的地表生物量的明显变化上。根据5年的河道区间耗水量资料,计算出该区间100 m宽的样带因输水而投入的水资源价值为0.65×104元,而输水后从地表植被生物量变化引起的地表生态响应价值为1.119×104元,投入产出比为1?1.72;地下水抬升的潜在经济价值是3.741×104元,总的投入产出比为:1?7.477,表明输水有显著的生态效益。  相似文献   

云南石林喀斯特小生境木本植物多样性特征   总被引：2，自引：0，他引：2  

俞筱押  李玉辉  马遵平 《山地学报》2007,25(4):438-447

喀斯特生境与生物多样性的关系及对人为干扰的响应是喀斯特生态恢复的重要内容。以石林世界地质公园为例对此进行研究。从喀斯特溶痕与植物生长发育关系角度看,石林的小生境可分出节理溶沟、裂隙溶沟、楔状槽沟、深溶蚀坑、溶蚀石堆、浅溶蚀盘、溶蚀穿洞、溶蚀井或圆形溶槽和溶蚀廊道等9种。这些小生境的长度在31~340 cm,宽度在10~261 cm。在原生林、次生林、灌丛和灌丛草地等四个群落中调查了各个小生境的木本植物,共记录40科92种,个体数11420株,其中以溶蚀廊道的木本植物总数最多,溶蚀穿洞最少。物种和数量保持最稳定的小生境是溶蚀石堆和裂隙溶沟。各小生境群落间的物种相似性指数很低。裂隙溶沟、深溶蚀坑、楔状槽沟、溶蚀石堆等小生境在人为强烈干扰后,仍保留有部分乡土植物繁殖体,其他小生境缺乏,这些繁殖体对生态严重退化区的喀斯特植被恢复具有重要意义。喀斯特生境的尺度影响森林植被的自然恢复。保护喀斯特地质遗迹可以促进生物多样性恢复和保护,石林世界地质公园提供了例证。  相似文献   

南水北调中线石家庄受水区地下水修复潜力及水位变化   总被引：1，自引：0，他引：1  

张光辉  费宇红  刘克岩  郝明亮  申建梅  王金哲 《地质通报》2007,26(5):583-589

在阐明地下调蓄的有关理念、评价原则和方法的基础上,揭示了南水北调中线石家庄受水区可利用地下调蓄库容19.11×108m3,连续30天调蓄下平均入渗强度为6.88×104～9.63×104m3/d·km2;在南水北调客水、减少开采量和利用当地雨洪进行地下调蓄下,10年后石家庄地下水漏斗的中心水位埋深将由现在的52.3m恢复至39.9～40.8m,漏斗面积由现在的401km2缩小至320～326km2;30年后中心水位埋深将恢复至22.8～31.4m,漏斗面积195～261km2。其中减采调蓄模式稳定地下水储存资源,当地雨洪调蓄模式增补储存资源,而南水北调客水直接参与地下调蓄的水量有限,主要作用是为减采和雨洪调蓄模式创造良好的实施前提条件。  相似文献   

INTEGRATED MANAGEMENT PLAN OF SEDIMENT AND ECOLOGICAL RESTORATION IN WATERSHEDS, A CASE STUDY IN CHINA     

Shuyou CAO  Xingnian LIU  Changzhi LI  Xiaozhang LEI  Er HUANG  Hualong DAI 《国际泥沙研究》2003,(2)

1 INTRODUCTION Soil erosion is serious in Western China. With the implementation of a development strategy for western China, soil and water conservation and ecological restoration in western China earn more attention because economic development requires parallel efforts on ecological restoration. To protect the ecology of the upper reaches of the Yangtze River, integrated management of sediment and ecological restoration are being conducted in Sichuan Province. The Yufeng Watershed…  相似文献