Carbon Fluxes from Different Pools in a Mined Area under Reclamation in Minas Gerais State,Brazil

Despite the benefits of grass cultivation and organic fertilization in mining areas undergoing reclamation, these practices may be associated to CO₂ emissions and soil organic matter (SOM) losses by priming effect. In the present study, we evaluated the changes on SOM pools and C–CO₂ emissions in a bauxite‐mined area under reclamation fertilized with poultry litter (PL) (0, 10, 20, and 40 Mg ha⁻¹) and cultivated with Brachiaria brizantha . Increases of about 3·5 times in the soil labile C were observed 1 year after experiment establishment. High C–CO₂ fluxes and a significant positive priming effect were observed in the presence of B. brizantha , increasing native C mineralization by nearly 4·9 times. Nevertheless, no net soil C loss was detected, probably because of the C inputs derived from B. brizantha , which offset these losses. In fact, the grass increased total organic C by 45% when fertilized with 40 Mg PL ha⁻¹. The data obtained suggest that the cultivation of B. brizantha fertilized with PL can be a promising option for rapid recovery in SOM in areas under reclamation. Copyright © 2016 John Wiley & Sons, Ltd.     

Application of the analytic hierarchy process to riparian revegetation policy options

While riparian vegetation can play a major role in protecting land, water and natural habitat in catchments, there are high costs associated with tree planting and establishment and in diverting land from cropping. The distribution of costs and benefits of riparian revegetation creates conflicts in the objectives of various stakeholder groups, and elicitation of importance weights of objectives and determination of rankings of a number of policy options by these stakeholder groups becomes critical in decision-making. The analytic hierarchy process (AHP) is a multicriteria analysis technique that provides an appropriate tool to accommodate the conflicting views of various stakeholder groups. The AHP allows the users to assess the relative importance of multiple criteria (or multiple alternatives against a given criterion) in an intuitive manner. This paper presents an application of AHP to obtain preference weights of environmental, social and economic objectives which have been used in ranking riparian revegetation policy options in a small catchment (watershed) in north Queensland, Australia. The preference weights towards environmental, economic and social objectives have been obtained for the various stakeholder groups (landholders, representatives of local sugar mill staff, environmentalists, recreational fishers and the local community). The AHP technique has proved useful in eliciting objectives and ranking policy options as well as in checking for consistency of the statements of stakeholder groups. Implementation of this approach requires a complex data elicitation process.     

Restoration of the mangrove vegetation in the Mahanadi delta,Orissa, India

In India, mangroves occupy 6740 km² of which the Mahanadi delta andBhitarkanika mangrove forests of Orissa cover 191.44 km², most of whichhas been severely overexploited. World wide concern to conserve mangrovesnecessitated propagation of mangroves to re-establish them on barren andswampy land along tidal creeks around Paradeep port of Orissa. Avicenniaofficinalis, Aegiceras corniculatum, Bruguiera parviflora, B. sexangula,Ceriops decandra, Excoecaria agallocha, Heritiera fomes, Kandelia candel,Rhizophora mucronata, Sonneratia apetala were vegetatively propagated andplanted over 10 ha of degraded salt-marshy wetlands of Mahanadi delta inpure and mixed stands depending on the intensity and the frequency of tidalinundation at the experimental site. Survival was significantly higher(80%) in S. apetala followed by A. officinalis, R. mucronata, K.candel and H. fomes (70–75%). S. apetala recorded the maximumgrowth in height (3.0 m after 2 years) whereas C. decandra showed theminimum growth (0.5 m). Growth performance was better with plants in mixedstands than the plantation with single species. This gives us hope topropagate and re-establish mangroves for conservation in scientificallymanaged plantations in a physiologically arid environment.     

W-OH新材料特性及在青海湖周边地区沙化地植生固沙中的应用

W-OH是一种新型的化学植生固沙材料,通过室内试验及青海湖周边地区的不同处理方式植生固沙试验表明,3%～5%浓度的W-OH材料在抗冻、抗压、抗拉、抗紫外线等性能均能达到青海湖周边地区植生固沙的要求,在处理方式喷涂W-OH+沟处理试验中取得了良好的植被恢复和治沙效果,适合在青海湖周边地区类似条件的地区进行推广应用。     

Causes of Sandstorm Disaster and Strategies against Desertification——A Case Study of Hexi Corridor in Northwest China

This case study outlines the problems faced by the peoples of the Hexi Corridor. These problems are serious and urgent, and are representative of those faced by other communities right across western China. The root causes are outlined and some remedies are suggested. The practical measures proposed under China's National Action Plan to Combat Desertification are described and discussed.     

Does Biochar Improve Establishment of Tree Seedlings in Saline Sodic Soils?

Reforestation of saline sodic soil is increasingly undertaken as a means of reclaiming otherwise unproductive agricultural land. Currently, restoration of degraded land is limited to species with high tolerances of salinity. Biochar application has the potential to improve physical, biological and chemical properties of these soils to allow establishment of a wider range of plants. In a glasshouse trial, we applied biochar made from Acacia pycnantha (5 Mg ha⁻¹) or no biochar to either a low (EC_e 4·75 dS m⁻¹, ESP 6·9), a moderate (EC_e 27·6 dS m⁻¹, ESP 29·3) or a high (EC_e 49·4 dS m⁻¹, ESP 45·1) saline sodic soil. The regional common reforestation species Eucalyptus viminalis and Acacia mearnsii were planted as tubestock in to the soils. Early establishment indicators, including growth, plant condition and nutrition, were assessed at the end of a simulated growing season, 108 days after biochar application. Application of biochar increased height, and decreased root : shoot and the concentration of Mn, N and S in plants of E. viminalis when grown in the highly saline sodic soil. Biochar application increased the concentration of B in leaves of E. viminalis and increased the concentration of P, K and S in leaves of A. mearnsii when grown in the low saline sodic soil. The results confirm that there is potential for biochar to assist in reforestation of saline sodic soils. Copyright © 2015 John Wiley & Sons, Ltd.     

土壤生物工程在北京山区公路绿化中的应用

山区公路边坡绿化不仅可以保护边坡,防治水土流失,而且还可以改善公路施工过程中对环境造成的创伤,已经成为公路边坡治理的重要内容。以北京市怀柔区琉璃河岸坡为试验示范区,以旱柳(Salix matsudana)作为主要的绿化植物,采用扦插、埋根、灌丛垫、柳篱挡墙、梢捆等土壤生物工程措施,对沿河公路路基边坡进行治理,并对施工完成5个月后的生长状况、护坡效果等进行观测调查。结果表明:5种土壤生物工程中旱柳的成活率均在90%以上,在试验区具有很好的适应性;在不同的工程类型、水淹与否等条件下,旱柳的生长状况表现出明显的差异,各措施按旱柳生长状况由好到差排序依次为梢捆、灌丛垫、埋根、扦插、柳篱挡墙;水淹1个月的旱柳基径和株高较未水淹的平均值分别小13.2%和21.4%。     

基于SEBAL模型评估干旱半干旱区人工灌丛植被对陆表蒸散的影响

评估人工灌丛植被重建对干旱半干旱区陆地生态系统蒸散的影响,不仅能揭示植被变化与水文过程的耦合机理,又可为区域生态治理与水资源管理提供科学指导。该研究利用Landsat-8OLI/TIR遥感影像及气象数据等驱动SEBAL模型,反演宁夏盐池县的年内不同日期的陆表蒸散,结合目视解译选取的人工灌丛区与对照草地,评估了人工灌丛植被对陆表蒸散的影响。结果表明:1)SEBAL模型的蒸散反演精度与站点观测结果较为一致,可用于干旱半干旱区蒸散反演及空间特征研究;2)盐池县人工灌丛植被区日平均蒸散为1.20mm/d,高于对照草地1.17mm/d的日平均蒸散量,即干旱半干旱区人工种植灌木林增加了生态系统水分消耗,但不同季节和不同生物地理条件下的蒸散增强作用存在差异,蒸散增强在8月份最大,而3、4月份呈现负效应;3)人工灌丛的密度越大、植被盖度越高,对陆表蒸散的增强作用越强,特别在NDVI0.4的高盖度情况下蒸散增强作用更加明显。由此可知,在水资源紧缺的干旱半干旱区开展以灌木树种为主的植被重建需在合理的生态水文阈值范围内开展,才能构建出稳定可持续的人工生态系统。     

Weather-Centric Rangeland Revegetation Planning

Invasive annual weeds negatively impact ecosystem services and pose a major conservation threat on semiarid rangelands throughout the western United States. Rehabilitation of these rangelands is challenging due to interannual climate and subseasonal weather variability that impacts seed germination, seedling survival and establishment, annual weed dynamics, wildfire frequency, and soil stability. Rehabilitation and restoration outcomes could be improved by adopting a weather-centric approach that uses the full spectrum of available site-specific weather information from historical observations, seasonal climate forecasts, and climate-change projections. Climate data can be used retrospectively to interpret success or failure of past seedings by describing seasonal and longer-term patterns of environmental variability subsequent to planting. A more detailed evaluation of weather impacts on site conditions may yield more flexible adaptive-management strategies for rangeland restoration and rehabilitation, as well as provide estimates of transition probabilities between desirable and undesirable vegetation states. Skillful seasonal climate forecasts could greatly improve the cost efficiency of management treatments by limiting revegetation activities to time periods where forecasts suggest higher probabilities of successful seedling establishment. Climate-change projections are key to the application of current environmental models for development of mitigation and adaptation strategies and for management practices that require a multidecadal planning horizon. Adoption of new weather technology will require collaboration between land managers and revegetation specialists and modifications to the way we currently plan and conduct rangeland rehabilitation and restoration in the Intermountain West.     

晋北丘陵风沙区不同植被恢复模式的水土保持效应

通过对山西右玉贾家窑阳坡退耕还林约20年后的4种植被恢复模式(自然恢复草地、油松林、柠条灌丛和油松—柠条林)土壤水分、理化性质、径流量和侵蚀量的测定,探讨了不同植被恢复模式的水土保持效应。结果表明:(1)4种植被恢复模式0—100cm土层土壤平均含水量无显著差异,油松林和自然恢复草地的土壤容重高于油松—柠条林和柠条灌丛,土壤总孔隙度的变化趋势与容重相反;(2)4种植被恢复模式0—20cm土层土壤粒度组成、pH、有机质、铵态氮和速效磷无显著差异,硝态氮和速效钾差异明显(P0.05);(3)4种植被恢复模式径流量没有明显差异,但土壤侵蚀量自然恢复草地和油松林显著高于柠条灌丛和油松—柠条林(P0.05);(4)覆盖度相似条件下,根系密度、近地表植被盖度和枯枝落叶层厚度是影响林草植被水土保持效应的主要因素。