南方岩质坡地生态恢复探讨

介绍和运用生态恢复有关理论,对南方岩质坡地的生态恢复一般规律进行了分析。在此基础上,介绍了适用的土壤固定方法和水土保持技术,并以植被混凝土绿化技术为例,建立了岩质坡地生态恢复过程模型。最后分析了开发利用应注意的问题。     

甘肃省森林生态系统保育土壤功能及其价值评估

为更加直观地认识森林的重要生态和经济地位,并为甘肃省生态经济建设的综合决策提供科学的理论依据,实现生态经济可持续发展。以甘肃省重点林区为研究对象,采用物质量和价值量相结合的评价方法,定量地评价甘肃省森林生态系统保育土壤功能和经济价值。结果显示：（1）甘肃省森林生态系统年固土总量为16 620.53万t,年固土总价值为22.10亿元;年保肥总量为988.56万t,年保肥总价值为356.71亿元,森林生态系统年保肥价值占到总固土保肥总价值的94.2%,森林生态系统保肥所产生的价值远远大于固土所产生的价值,占据了主导地位;森林生态系统固土保肥总价值为380.80亿元/年,占甘肃省森林生态系统服务总价值（1 825.92亿元/年）的20.86%。（2）所选取的19种林分类型中,灌木林（222.10亿元/年）在整个森林生态系统固土保肥总价值中占据支配地位,占到总价值的58.32%;乔木林中,其他硬阔类（30.27亿元/年）、栎类（24.25亿元/年）、阔叶混交林（22.22亿元/年）三者固土保肥功能和产生价值较大。甘肃省森林生态系统保育土壤功能及其价值在整个森林生态系统服务中起到至关重要的作用,尤其是灌木林、其他硬阔类、栎类以及阔叶混交林提供的生态系统服务占据优势。     

黄果树风景名胜区低效林分改造措施及生态恢复对策

阐述了黄果树风景名胜区低效林分的现状、特征。根据现有林分和立地条件，将研究区的低效林分划分为低产经济林、低效落叶阔叶林、低效常绿针阔混交林、低效灌木林、低效石山灌丛等5种类型，又把低效石山灌丛分为封山育林和困难地段造林。采用封、补、改、造、抚等措施对不同的低效林分类型，采取不同的改造方式进行改造。并结合该区自然、社会、经济发展的实际情况，从生态、生活和生产方面提出了黄果树风景名胜区石灰岩山地生态建设的对策建议。     

世界水土保持学会副主席,水土保持专家José Luis Rubio先生论森林火灾后土壤的保护与修复：生物工程的作用

[目的]讨论火灾地区土壤保护的基本方法,旨在从生物多样性和美学价值方面,阐述新兴生物工程领域在修复与固结土壤,保护土壤免遭不同类型侵蚀,维持景观质量等方面中的应用。[方法]通过综述和评价现行生物工程技术在西班牙森林火灾后土壤保持和土壤修复中的应用,阐述了有关基本原理,并介绍了一些生物工程技术在受火灾影响的不同地区的成功应用案例。[结果]生物工程技术用于森林火灾后土壤保护和修复的重要基础知识部分仍基于土壤保持的一些传统原理,尤其在与具体干预的立地和简单技术应用的生态一致性方面。同时也不应低估新近土木工程的作用。这些土木工程技术(包括金属笼的使用)为生物要素(主要是植物物质)发挥更大作用提供了条件,而这些生物要素是在特定干预区气候或生物物理条件下发挥固结土壤作用的重要因素。与活体材料一起使用的还有各种生物物质,例如植物残留物,砍下的灌木,木质化元素,以及多种土工织物。这些技术可以归结分为4组主要形式:(1)土壤保护技术,(2)地面稳定技术,(3)重建技术组合,(4)其他稳定技术。[结论]用于土壤保护的生物工程技术提供了一种更为环保和具有长期有效性的方法。它同时具有耗资低,适应性强和提供多功能景观效益等优势。然而,生物技术也存在一些缺陷,例如人力资源需求,缺乏有关知识和合适的植物物质,特别是在一些干旱气候地区。尽管如此,生物工程方法在满足森林火灾影响后土壤保护的紧急干预措施这类新需求过程中表现出其正在崛起,有应用前途和快速发展的态势。     

常绿阔叶林退化生态系统恢复过程物种多样性的发展趋势与速率

常绿阔叶林退化生态系统恢复的关键是物种多样性的恢复发展。对大明山区常绿阔叶林退化生态系统植被恢复过程物种多样性的发展趋势和速度进行了研究。结果表明 :1.大明山中山区和低山丘陵区退化生态系统恢复过程中物种多样性的发展速度存在很大差异。中山区采伐森林后炼山种植杉木 ,经过 2 0年的自然恢复 ,在 60 0 m2的调查面积里出现了 178个物种 ,其中乔木层就有 58个物种 ,并且 2 0年左右就能形成以阳性阔叶先锋树种与中生性阔叶树种为共优势的森林群落 ,大约 60～ 10 0年就能形成中生性的常绿阔叶林。而在低山丘陵区 ,常绿阔叶林退化生态系统恢复过程物种多样性的发展速度相当缓慢 ,恢复期为 2 0～ 30年的群落 ,在 4 0 0 m2 样地上仅出现 2 2个物种 ,乔木层只有 3个物种 ;而且由于人为的干扰不断 ,这一地区的马尾松林很难恢复到地带性的常绿阔叶林 ,只能发展成相对长期稳定的人为偏途顶极。 2 .在退化生态系统的恢复过程中 ,物种数量的变化呈前期迅速增加 ,中期减少 ,后期维持一定水平的发展趋势。 3.单位面积上个体数量的变化在群落的不同层次表现不同 ,乔木层在 1～ 2 0年间个体数量呈递增趋势 ,2 0年后表现为递减趋势 ;灌木层的个体数呈不断增长的趋势 ;而草本层的个体数量则呈非线性发展。4 .β     

利益相关者对塔里木河下游荒漠河岸林生态系统服务的认知度分析

近50年以来,塔里木河下游生态环境曾因人类不合理开发利用而导致严重退化。自2000至2013年实施的人工生态输水工程对胡杨为主体的荒漠河岸林的恢复及其生态系统服务功能的提高产生了积极影响。通过问卷调查的方法分析了利益相关者对塔里木河下游荒漠河岸林生态系统服务的认知程度。结果表明:88.1%的被调查者对荒漠河岸林生态系统服务有深刻的认识,7.8%的人不清楚;84%的被调查者认为荒漠河岸林在防止沙(荒)漠化方面的效益最高,仅有8.1%被调查者认为提供建筑材料和动物饲料等方面效益最高;被调查者对人工输水后生态环境变化的感知度依次为:灰尘和沙尘暴减弱沙(荒)漠化减少胡杨长势改善胡杨幼树增多河岸林面积增加;被调查者对人工输水的支付意愿有所差异,其中15.1%的人对其态度模糊,7.8%的人不愿意支付,有36%的被调查者愿意支付工资的1%,15.4%的被调查者愿意支付工资的1%,12%的人愿意支付工资的2%,3.8%的人愿意支付工资的3%,7.9%的人愿意支付工资的3%。问卷调查的结果表明,被调查者对塔里木河下游荒漠河岸林生态系统服务的认知度和支持率相当高,体现出生态输水的社会效益显著。     

南方水土保持林引种选择

水土保持林能有效的控制水土流失,在福建漳州通过林木引种选择适合该地区立地条件的树种,在此又介绍了8种引种比较成功的树种,利用它们的特性,探讨治理水土流失、生态重建的途径。     

长江上游森林水源涵养功能及空间分布特征

以长江上游森林生态系统为研究对象,按照植被类型将研究区域划分成11个评估单元。根据研究区各森林类型林冠层、枯枝落叶层和土壤层的指标数据和2001年NOAA影像,结合野外调查,应用GIS技术对整个长江上游森林水源涵养功能及其在空间上的分布特征进行了探讨。结果表明:(1)长江上游森林水源涵养功能平均值为79.33 mm。林冠层、枯落物层、土壤层水源涵养功能平均值分别为1.29,2.81和75.21 mm。长江上游森林水源涵养总量为1.667 5×1010t。林冠层、枯落物层和土壤层分别占涵养总量的1.63%,3.54%和94.81%。土壤层是森林系统水源涵养总量的主体。(2)长江上游森林水源涵养功能由南向北呈现先增加后减少的抛物线趋势,由西向东表现出近似幂函数曲线的逐渐减少趋势。这与林冠层的变化趋势相反,与土壤层的变化趋势具有一致性。(3)在水平方向上,长江上游森林水源涵养功能以岷山—茶坪山—夹金山—锦屏山—玉龙山一线为界,表现出西强东弱的空间分布格局;在垂直方向上,森林水源涵养功能随着海拔的升高逐渐增加,至海拔4 200 m左右,出现减少的趋势。     

Restoration Affect Soil Organic Carbon and Nutrients in Different Particle‐size Fractions

Desertification is reversible and can often be prevented by adopting measures to control the causal processes. Desertification has generally decreased in most of the arid and semiarid areas of China during the last few decades because of the restoration of degraded vegetation and soil nutrients. However, little is known about the responses of soil nutrients in different particle‐size fractions to the restoration process and about the importance of this response to the restoration of bulk‐soil nutrients. In this study, we separated bulk‐soil samples in different sieve fractions: coarse‐fine sand (2·0–0·1 mm), very fine sand (0·10–0·05 mm) and silt + clay (<0·05 mm) fractions. Soil organic carbon (SOC), N, P and K contents stored in the silt + clay were greater than the contents of non‐protected nutrients in the coarser fractions. During the restoration of desertified land, the content and stability of bulk‐soil SOC, total N and P and available N, P and K increased with increasing nutrient contents in all fractions. Topsoil nutrients stored in coarse‐fine sand and very fine sand fractions were more sensitive than those stored in the silt + clay fraction to the fixation of mobile sandy lands and vegetation recovery. The changes of bulk‐soil nutrients and their stability were decided by the soil nutrients associated with all particle‐size fractions. Path analysis revealed that SOC and total nutrients in very fine sand and available nutrients in coarse‐fine sand were the key factors driving the soil recovery. These results will help us understand soil recovery mechanisms and evaluate the degree of recovery. Copyright © 2015 John Wiley & Sons, Ltd.     

Dynamics of soil chemical properties in shifting cultivation systems in the tropics: a meta‐analysis

The forest cultivation system (slash‐and‐burn or shifting cultivation) has contributed to the transformation of social systems since the early Neolithic period. Despite being considered by conservationists and public policymakers as a system of low productivity that generates environmental degradation and contributes to the maintenance of rural poverty, the shifting cultivation system (SCS) is being declared a practice that is highly ecologically and economically efficient. Such dichotomy of opinions is the consequence of the disparate results of studies assessing the effects of SCS on soil properties of rainforests throughout the last three decades. To circumvent this apparent inconsistency, we used a systematic quantitative review method (meta‐analysis), with the objective of integrating and synthesizing the data published in the literature to assess the overall effects of SCS on soil chemical properties. Four variables traditionally assessed in primary studies were chosen for the meta‐analyses: pH, cation exchange capacity (CEC), total carbon (Total C) and total nitrogen (Total N). Our results show that pH values increase under SCS conditions, while Total N and C content are significantly reduced under SCS. No significant impacts are observed on CEC. Our results on pH and CEC support the position from researchers who argue for the sustainability of SCS and highlight the importance of evaluating the soil system as a soil/vegetation complex. Also, our results indicate that soil chemical properties under SCS scenarios are better conserved and more readily recoverable, provided there is a rather longer fallow period than has been traditionally employed.     

Soil Organic Carbon and Inorganic Carbon Accumulation Along a 30‐year Grassland Restoration Chronosequence in Semi‐arid Regions (China)

Carbon accumulation is an important research topic for grassland restoration. It is requisite to determine the dynamics of the soil carbon pools [soil organic carbon (SOC) and soil inorganic carbon (SIC)] for understanding regional carbon budgets. In this study, we chose a grassland restoration chronosequence (cropland, 0 years; grasslands restored for 5, 15 and 30 years, i.e. RG5, RG15 and RG30, respectively) to compare the SOC and SIC pools in different soil profiles. Our results showed that SOC stock in the 0‐ to 100‐cm soil layer showed an initial decrease in RG5 and then an increase to net C gains in RG15 and RG30. Because of a decrease in the SIC stock, the percentage of SOC stock in the total soil C pool increased across the chronosequence. The SIC stock decreased at a rate of 0·75 Mg hm⁻² y⁻¹. The change of SOC was higher in the surface (0–10 cm, 0·40 Mg hm⁻² y⁻¹) than in the deeper soil (10–100 cm, 0·33 Mg hm⁻² y⁻¹) in RG5. The accumulation of C commenced >5 years after cropland conversion. Although the SIC content decreased, the SIC stock still represented a larger percentage of the soil C pool. Moreover, the soil total carbon showed an increasing trend during grassland restoration. Our results indicated that the soil C sequestration featured an increase in SOC, offsetting the decrease in SIC at the depth of 0–100 cm in the restored grasslands. Therefore, we suggest that both SOC and SIC should be considered during grassland restoration in semi‐arid regions. Copyright © 2016 John Wiley & Sons, Ltd.     

Long‐term changes in the floristic composition and soil characteristics of reclaimed sodic land during eco‐restoration

The study was conducted under the “Uttar Pradesh Sodic Lands Reclamation Project” to examine changes that occurred in the reclaimed sodic land in two districts of Uttar Pradesh, India. The study focuses on long‐term seasonal changes in the floral diversity and soil characteristics of the reclaimed sodic land over a period of 10 y. The changes in the floristic composition, plant density, and soil characteristics (microbial biomass carbon [MBC], pH, exchangeable‐sodium percentage (ESP), and electrical conductivity) were compared among the different study plots after different years of sodic‐land reclamation. The study plots comprised reclaimed land with rice–wheat cultivation; semireclaimed land under rice cultivation only and nonreclaimed barren sodic land. There was a significant variation in the floristic composition of the three study plots. Dominance in the floristic composition was shifted from monocotyledonous weeds in the nonreclaimed sodic land to dicotyledonous weeds in the reclaimed land after 10 y of reclamation. Among the soil characteristics, the most remarkable changes were observed in soil MBC and ESP during the course of sodic‐land reclamation. Soil MBC increased up to 480% and ESP values decreased up to 79% in the reclaimed plots with reference to the nonreclaimed plots. The soil amelioration was more pronounced in the upper layer (0–30 cm) as compared to the lower layer (below 30 cm depth). A positive significant correlation was revealed between soil MBC and floristic composition of the reclaimed plots. These changes in floristic composition and soil characteristics could be used as good indicators of the eco‐restoration of the sodic lands. The present study provides useful insights in understanding the temporal progress of eco‐restoration in the reclaimed sodic lands.     

Soil microbial biomass and community composition as affected by cover crop diversity in a short‐term field experiment on a podzolized Stagnosol‐Cambisol

Background: Cover cropping appears as a useful land management practice with numerous benefits for ecosystem functions. Aim: The objectives of this study were to determine the effects of different winter cover crops on soil microbial biomass, activity, and community composition in intensively managed agriculture systems as function of cover crop diversity. Methods: For this purpose, an on‐farm experiment was conducted at a podzolized Stagnosol‐Cambisol during seven months growing oil radish as single cover crop and five different cover crop mixtures comprising 5 to 13 plant species. A fallow treatment was used as control. Phospholipid fatty acids were used to determine the soil microbial biomass and soil microbial community composition. Basal respiration of the soil microorganisms was measured as a proxy for microbial activity. Results: The results show that none of the cover crop mixture could increase soil organic carbon or total nitrogen content. Three cover crop mixtures and oil radish as single cover crop significantly increased soil microbial biomass by about 50% and all of the investigated cover crops significantly increased microbial respiration and metabolic quotient by 50–150%. Only highly diverse cover crop mixtures significantly increased individual microbial groups such as Gram‐positive and Gram‐negative bacteria, actinobacteria, and saprotropic and mycorrhizal fungi by about 20% compared to the control. However, the ratio of fungi to bacteria was not influenced by any of the cover crop mixtures under study. Conclusion: These findings corroborate that aboveground plant diversity is linked to belowground microbial diversity.     

Cost‐Effective Targeting Soil and Water Conservation: A Case Study of Changting County in Southeast China

Soil erosion is by far the greatest cause of land degradation and other environmental and socio‐economic problems in China. Although various conservation methods are widely utilized to reduce soil erosion and to sustain agricultural production, the cost‐effectiveness and selection of these methods are less known. Using our survey and ecological data, this study evaluated four soil and water conservation methods in Changting County, Southeast China. The results show that the disparity of conservation costs is much larger than that of ecological benefits. Planting fruit trees is a kind of conservation through primarily economic development. Closing hillsides for afforestation is most cost‐effective, followed by forest fertilizing, and planting trees and grass. Our findings suggest that comparatively lower cost conservation methods, for example closing hillsides for afforestation, should be considered in priority if initial ecological conditions can meet the requirements of the method. Copyright © 2015 John Wiley & Sons, Ltd.     

Selection of Adequate Species for Degraded Areas by Oil‐Exploitation Industry as a Key Factor for Recovery Forest in the Ecuadorian Amazon

One of the requirements for the forest restoration of soils disturbed by the oil‐exploitation industry is that saplings be able to endure soil‐adverse conditions. In this study, saplings of 20 species susceptible to be used in reforestation programs were evaluated for their ability to grow on substrates derived from soils disturbed by petroleum extractions in the Ecuadorian Amazon. Seeds of each species were planted in germination trays. Once seedlings reached 5 cm in height they were transplanted to plastic bags with three treatment substrates: two derived from petroleum‐exploitation activity (soils from mud and drill cutting cells and from areas surrounding oil wells) and a control soil. Plant survival rate, stem height, and diameter were measured on a weekly basis until 14 weeks after transplantation, when we harvested the plants and also measured plant biomass and calculated the Dickson quality index for each species. Oil‐exploitation by‐product substrates impaired the performance of many saplings, with the substrate from mud and drill cutting cells being the one that most affected plant performance. Only saplings of five native species in the Amazon basin—Apeiba membranaceae, Cedrelinga cateniformis, Inga densiflora, Myroxylon balsamum, and Pouroma cecropiifolia—exhibited high or similar Dickson quality index values in all soil treatments and performed better than the rest. The use of these five species in remediation of soils disturbed by petroleum extraction in the Amazon basin could prove important because of their high potential to adapt to these disturbed sites. Copyright © 2016 John Wiley & Sons, Ltd.     

A systems analysis of soil and forest degradation in a mid‐hill watershed of Nepal using a bio‐economic model

Forest degradation, manifested through decline in forest cover, and the resulting soil erosion and organic carbon losses, is a serious problem caused by a complex coupling of bio‐physical, socio‐economic and technological factors in the Himalayan watersheds. Greater understanding of the linkages between these factors requires a systems approach. We have proposed such an approach using a bio‐economic model to explore the system behaviour of forest degradation, soil erosion, and soil C losses in the forest areas. The outcome of the model simulation over a 20‐year period indicates that soil erosion and C loss rates may increase more than four‐fold by the year 2020 under the existing socio‐economic and biophysical regime (the base scenario). Reductions in the population growth rate, introduction of improved agricultural technology and increase in the prices of major agricultural crops can help slow down the rates of forest decline, soil erosion and C loss or even stabilize or reverse them. The results suggest that economic incentives may be highly effective in the reduction of soil loss, as well as C release to the atmosphere. Copyright © 2005 John Wiley & Sons, Ltd.     

Restoration of Plant and Animal Communities in a Sanitary Landfill: A 10‐year Case Study in Hong Kong

This study was conducted in the South East New Territories landfill in Hong Kong, with the objectives to (i) investigate the plant and animal communities' establishment and performance within 10 years after restoration and (ii) provide important information on pioneer plants species selection recommendations for restoring sanitary landfills. The studying sites were re‐vegetated in 2003, with 14 pioneer plant species, including Acacia auriculiformis, A. confusa and Schefflera heptaphylla, planted. In total, four permanent quadrats (10 m × 10 m) were used for monitoring at three restored sites (sites E, N and S) and the control site C. The soil properties and plant and animal communities inside plots were investigated annually in summer and winter between 2003 and 2014. The similarity of plant and animal communities between the restored and control sites was compared using Jaccard's index. Ten years after restoration, animal and plant communities were gradually established at all sites. No animal was introduced into the restored sites in 2003; however, there were 29, 31 and 44 animal species recorded at sites E, N and S, respectively, between 2003 and 2012. Within the studying period, 38 plant species (trees: 52·63%, shrub: 21·05%, herbs: 23·68% and climber: 2·63%) were recorded in all sites and 17 (36·84%) of them were self‐seeding. Exotic species, such as those from the family Acacia and Mimosaceae, were dominant at all restored sites, which implies that exotic species are more competitive and suitable to be used as pioneer species in sanitary landfill restoration. Copyright © 2015 John Wiley & Sons, Ltd.     

Management of Grazing Intensity in the Semi‐Arid Rangelands of Southern Australia: Effects on Soil and Biodiversity

Overgrazing contributes to rangeland degradation altering plant community composition, erosion and biodiversity. Little unanimity in the literature exists on the effects of livestock grazing on soil carbon and biodiversity, in part, due to uncontrolled grazing pressure from native and feral animals. Paired paddock contrasts at three, long‐term (>8 years) study locations in the southern Australian rangelands were used to examine the effects of managing grazing intensity through the use of exclusion fencing and rotational grazing on soil organic carbon (SOC), soil nitrogen (TN), ground cover and biodiversity (flora and invertebrates). Grazing management had no effect on SOC or TN on grey soils (Vertisols), but for red soils (Lixisols), significantly higher levels of SOC were found for both the 0 to 5 and 5 to 10‐cm soil depths (0·3% and 0·27% respectively) and associated with increased TN. We found strong and consistent relationships among SOC and higher perennial (p < 0·001), higher litter (p < 0·05) cover and close proximity to trees (p < 0·05). Managing grazing intensity resulted in significantly higher perennial ground cover (p < 0·001) on Vertisols (8·9 to 11%) and Lixisols (12·5 to 15%) and higher plant diversity (both native and exotic) but negatively impacted invertebrate diversity, indicating trade‐offs between production and resources. We provide evidence that the effects of grazing management on SOC are mediated by ground cover and increased organic matter supply and/or reduced soil carbon redistribution (erosion), which indicates that the management of grazing intensity may provide a tool to avoid soil carbon loss in rangelands. Copyright © 2016 John Wiley & Sons, Ltd.     

典型退化山地生态系统植被恢复阶段分类——以小浪底库区山地为例

 在调查黄河小浪底山地植物物种多样性指数和海拔、坡度、坡向、土壤状况等环境因素的基础上,采用主成分分析的方法对生态因子进行筛选,根据影响因子的作用大小,采用聚类分析的方法对样地进行群落恢复进程的分类,利用判别分析技术建立各恢复阶段的判别公式。结果表明:1)研究区植物群落可以划分为15种类型,其中乔木群落4个,灌草群落6个,草本群落5个;2)土壤和地形等环境因子、土壤流失等生态因子对多个公共因子都有较大的载荷。多样性指数H′/sup>,D1,P,Jsw,D2等在第1主分量上、石砾含量在第2主分量上、土壤流失程度、土壤厚度以及坡向和土壤类型在第2、第3主分量上都有较大载荷,海拔在3个主分量上载荷都较小;3)黄河小浪底山地植被恢复期可以分为4个恢复阶段:恢复初期阶段,其群落占27%;进展阶段,其群落占40%;恢复中期阶段,其群落占20%;恢复稳定阶段,其群落占13%;4)所建立的判别模型是可靠的,在判识植被恢复阶段有显著效果。