Development of plant communities after restoration of the Antaibao mining site,China

To investigate the dynamic changes in the artificial vegetation in an abandoned mining site,we analyzed the relationships among community types,environmental variables and community structure in the process of vegetation restoration in the Antaibao mining site,China by survey of the communities and use of biological dating methods.By means of the quantitative classification method (two-way indicator-species analysis,TWINSPAN) and the ordination technique (de-trended correspondence analysis,DCA; and de-trended canonical correspondence analysis,DCCA),the plant communities were classified into seven groups:community Ⅰ,Robinia pseudoacacia + Pinus tabulaeformis-Caragana korshinskii-Agropyron cristatum; community Ⅱ,Robinia pseudoacacia-Hippophae rhamnoides-Artemisia capillaries; community Ⅲ,Ulmus pumila-Elaeagnus angustifolia-Artemisia capillaries;community Ⅳ,Caragana korshinskii-Agropyron cristatum+Artemisia capillaries;community Ⅴ,Hippophae rhamnoides-Elymus dahuricus;cornrnunity Ⅵ,Elaeagnus angustifolia+Hippophae rhamnoides-Brassica jucea;community Ⅶ,Hippophae rhamnoides+Elaeagnus angustifolia-Salsola collina.We conclude that the community types and diversity are mainly influenced by the succession time and the soil organic matter content.The forest community is more adaptable to the special inhabitation than the shrub community.     

Succession in Bird and Plant Communities over a 24‐Year Chronosequence of Mine Rehabilitation in the Australian Monsoon Tropics

We compared the bird and woody plant communities of 2 to 24‐year‐old rehabilitation areas at Gove bauxite mine (20 km²) in the seasonal tropics of northern Australia, where Alcan has maintained a consistent rehabilitation program since it began operation in 1974. Birds were censused every second month over 2 years in 30 widely separated 0.25‐ha plots, representing five chronosequence stages. These were also compared with six (“off‐mine”) plots adjacent to the mine, which represented the annually burnt open forest typical of the region. Short‐lived Acacias dominated the early chronosequence stages, whereas eucalypts dominated in later stages. Mean avian species richness and abundance increased significantly along the chronosequence, with values for the oldest rehabilitation plots being very similar to those for the off‐mine plots. However, analyses of similarity revealed that the bird communities of the oldest rehabilitation plots were distinct from those of the off‐mine plots, indicating that succession in rehabilitation areas is not following a direct trajectory toward the native open forest surrounding the mine. Several hollow‐nesting bird species were scarce or absent in the rehabilitation areas, probably reflecting the absence of older hollow‐bearing trees. Many differences between the rehabilitation and the off‐mine areas in vegetation structure, woody flora, and avifauna appear to be related to the exclusion of fire from the minesite. We recommend the initiation of experiments designed to assess the effects of fire on the biota but caution against the use of fires for the majority of rehabilitation areas.     

高寒地区路堑边坡植被恢复效果

以大兴安岭地区阿荣旗至博客图段高速公路边坡作为研究对象,研究厚质基层喷附技术和植生混凝土喷附技术的植被恢复效果。结果表明:1)从植物群落组成情况和群落相似性系数来看,两种技术的总体恢复效果差别不明显,但植生混凝土喷附坡面植物群落更为接近自然水平。2)同样基于植物群落组成和群落相似性系数,两种技术在阴坡和阳坡上的恢复效果存在明显不同。3)土壤全氮和有机质含量的适当增长可以促进植物群落发展,而土壤速效磷含量的增长会抑制其发展。4)推荐较为合理的物种搭配为艾蒿、柳蒿、羊草、贝加尔针茅、兴安胡枝子、紫穗槐和兴安柳。研究可改善这两种生态恢复复方式在该地区的应用,优化物种配置,防止二次退化问题的出现,为后期养护、管理提供理论依据。     

Poor recovery of woody vegetation on sand and gravel mines in the Darwin region of the Northern Territory

Summary Sand sheets near Darwin support a distinct heathland vegetation type which includes the habitat of several threatened species. Sand and gravel are extracted from shallow mines in this region. Woody vegetation recovery in 31 small, shallow former sand or gravel mine sites near Darwin that were up to 27 years old was assessed and compared to paired unmined control sites. Recovery in vegetation structure within each mine was calculated as the percentage of that in the control site. Mined sites recovered about 50% of their stem count and canopy cover, but only about 10% of basal area and mature tree count. Gravel mines showed poorer recovery than sand mines. Time since mining had no significant effect on the extent of recovery, but deeper mines had significantly poorer recovery. Only 35% of woody species in sand controls were present in mine sites, and 41% of gravel control species were present in former mine sites. It is unlikely that recovery will significantly improve in coming decades. Sand mining affects about 40 ha of land per year in this region, but is likely to increase in the future. If Darwin expands to a population of 1 million people, and mine sites are not fully rehabilitated, all of the sand‐sheet vegetation in the region could be removed in the next 100 years. Improved rehabilitation and protection is crucial for the conservation of heathland vegetation in this region.     

中国东北地区流动沙丘生态系统丘间低地地下芽库的时空变化

中国东北地区流动沙丘生态系统丘间低地地下芽库的时空变化 地下芽库在半干旱区沙丘生态系统植被恢复中起着重要作用。然而,目前针对流动沙丘丘间低地地下芽库时空变化的研究却很少。本研究通过调查一个生长季内5个不同面积流动沙丘丘间低地地下芽库的大小和组成,确定流动沙丘丘间低地地下芽库的时空变化。研究结果显示,中等面积丘间低地的总芽库密度与分蘖芽密度最高,茎基部芽密度呈相反趋势,而根茎芽密度不随丘间低地的面积变化而变化。地下芽库大小具有明显的季节变化特征。总芽密度在8月份达到高峰,10月份最低,根茎芽密度变化趋势与总芽密度相似,而茎基芽密度变化趋势与总芽密度相反,分蘖芽密度的变化不明显。以上结果表明,地下芽库密度随丘间低地的面积和季节变化而变化。这一结果有助于认识流动沙丘生态系统中植物生长的适应策略,并可为半干旱区沙丘植被恢复和保护提供理论指导。     

An evaluation of the use of translocated blanket bog vegetation for heathland restoration

Abstract. The decision was taken by an opencast coal mining company to translocate on-site blanket bog vegetation, on completion of mining, at a site in Co. Durham, UK, both to preserve it and to use it to enhance recolonization. The vegetation of the treatments was monitored for seven years after site completion and this paper reports on the progress of the translocated material and its effect on recolonization. Translocation of large turves of blanket bog into carefully prepared receptor cells preserved most of the vegetation intact, but resulted in severe decline in the frequency of Sphagnum, while the design of the receptor site as strips of translocated vegetation enclosing strips of spread, stored peat accelerated recolonization of the intervening bare peat by Calluna vulgaris, but not of other target species. This attempt to translocate blanket bog vegetation and at the same time use it to accelerate recolonization was only partly successful. It was concluded that the ecological requirements of species known to be significant for ecosystem function, such as Sphagnum, must be fulfilled if translocation of blanket bog is to be attempted in future.     

Towards a decision support system for stream restoration in the Netherlands: an overview of restoration projects and future needs

Stream restoration is one of the answers to the lowland stream deterioration. For making proper choices in stream restoration; one firstly needs to understand the complex spatial and temporal interactions between physical, chemical and biological components in the stream ecosystem. Several ecological concepts on the four dimensions, scale and hierarchy in a stream ecosystem are integrated into the 5-S-model. This model provides the theoretical backbone of the first outline of a decision support system for stream restoration. Stream restoration is developing fast in the Netherlands. In 1991, 70 projects were counted, in 1993 there were 170, and this number increased in 1998 to 206. Positive signs in this increase in the number of stream restoration projects are the increase in the amount of money, in background studies, in improvement of the selection process of stretches to be tackled, and the broadening of the objectives and measures. Negative signs are amongst others that measures often deal only with stream hydrology and structures in-stream. The catchment takes no part. Furthermore, bottlenecks often relate to finances and agreement between people and/or organisations. Finally, the first steps towards a decision support system for stream restoration are made. The system presented provides only information based on which measures should be taken. `Where and how' these measures need to be taken remains a challenge for the future.     

Evaluating soil seed banks of phosphate mining restoration in the hyper-arid Negev desert

Ecological systems are severely damaged by the anthropogenic disturbance of mining. Phosphate open-pit mining fields cover over 200 km² of the Negev desert, Israel. However, the effects of the ongoing mine site restoration efforts on the plant community have not been studied. Plants and their seed banks have a major role in ecosystem processes and restoration. In this study, we focused on three mining sites, restored in different years, along Zin River valley. We compared the plant community of restored mining plots within these areas to adjacent natural plots. We asked whether plant community germination potential from the soil seed bank differs between the restored plots and the adjacent natural plots within a mining site. We hypothesized that: (1) there is a lack of seed bank in the restored plots; (2) the altered soil composition at the restored plots inhibits germination. We used soil samples collected from the different mining sites and set up greenhouse experiments. One experiment compared natural and restored areas with different soil treatments. In another experiment, we added native seeds to test their germination potential on restored soil. Our results indicate that lack of seed bank is the major limiting factor hindering germination and not the composition of the soil after restoration. Our findings shed light on the constraints of seed bank establishment in post-mining areas of hyper-arid regions. We suggest considering active restoration practices to facilitate natural dispersal and improve seed bank establishment.     

Local habitat restoration in streams: Constraints on the effectiveness of restoration for stream biota

Summary   The restoration of physical habitat has emerged as a key activity for managers charged with reversing the damage done by humans to streams and rivers, and there has been a great expenditure of time, money and other resources on habitat restoration projects. Most restoration projects appear to assume that the creation of habitat is the key to restoring the biota ('the field of dreams hypothesis'). However, in many streams where new habitat is clearly required if populations and communities are to be restored, there may be numerous other factors that cause the expected link between habitat and biotic restoration to break down. We discuss five issues that are likely to have a direct bearing on the success, or perceived success of local habitat restoration projects in streams: (i) barriers to colonization, (ii) temporal shifts in habitat use, (iii) introduced species, (iv) long-term and large-scale processes, and (v) inappropriate scales of restoration. The purpose of the study was primarily to alert ecologists and managers involved in stream habitat restoration to the potential impacts of these issues on restoration success. Furthermore, the study highlights the opportunities provided by habitat restoration for learning how the factors we discuss affect populations, communities and ecosystems.     

Vegetation restoration patterns and their relationships with disturbance on the Giant Panda Corridor of Tudiling, Southwest China

Human activities such as deforestation, cultivation, and overgrazing have contributed to the destruction of forest ecosystems in the upper Minjiang River basin for a long time, which has led to the reduction in forest coverage and biodiversity. On the Giant Panda Corridor of Tudiling in this basin, the effects of the existing disturbance regimes on plant communities after the vegetation restoration in the 1980s were assessed, and the community composition, the species diversity and their relationships with environmental factors significantly associated with the disturbance were analyzed using the transect sampling method, the two-way indicator species analysis (TWINSPAN) and the detrended canonical correspondence analysis (DCCA). The results were as follows: communities could be classified into six types, and species were clustered into four functional groups (responsive to disturbance, retarded disturbance, resistant to intermediate disturbance, and resistant to heavy disturbance) based on both TWINSPAN and DCCA. DCCA with species composition of plots is similar to that with species diversity of plots. The communities were separated into distinct groups along the DCCA axis, and this pattern was significantly correlated with environmental factors. Elevation differences, shape, slope, distance to roads, and the number of paths in the plots had an evident influence on the distribution of the species and communities. Environmental factors including slope, distance to roads, and the number of paths revealed the gradient of disturbance among the communities along the DCCA axis. High disturbance intensity caused significantly lower species diversity and inhibited the regeneration of vegetation compared with the more diverse undisturbed communities. Artificial restoration was more effective than natural restoration in maintaining high species diversity. The process of succession was inhibited in natural restoration because of the failure of tree establishment, growth, and survival during regeneration.     

Vegetation restoration patterns and their relationships with disturbance on the Giant Panda Corridor of Tudiling, Southwest China

Human activities such as deforestation, cultivation, and overgrazing have contributed to the destruction of forest ecosystems in the upper Minjiang River basin for a long time, which has led to the reduction in forest coverage and biodiversity. On the Giant Panda Corridor of Tudiling in this basin, the effects of the existing disturbance regimes on plant communities after the vegetation restoration in the 1980s were assessed, and the community composition, the species diversity and their relationships with environmental factors significantly associated with the disturbance were analyzed using the transect sampling method, the two-way indicator species analysis (TWINSPAN) and the detrended canonical correspondence analysis (DCCA). The results were as follows: communities could be classified into six types, and species were clustered into four functional groups (responsive to disturbance, retarded disturbance, resistant to intermediate disturbance, and resistant to heavy disturbance) based on both TWINSPAN and DCCA. DCCA with species composition of plots is similar to that with species diversity of plots. The communities were separated into distinct groups along the DCCA axis, and this pattern was significantly correlated with environmental factors. Elevation differences, shape, slope, distance to roads, and the number of paths in the plots had an evident influence on the distribution of the species and communities. Environmental factors including slope, distance to roads, and the number of paths revealed the gradient of disturbance among the communities along the DCCA axis. High disturbance intensity caused significantly lower species diversity and inhibited the regeneration of vegetation compared with the more diverse undisturbed communities. Artificial restoration was more effective than natural restoration in maintaining high species diversity. The process of succession was inhibited in natural restoration because of the failure of tree establishment, growth, and survival during regeneration.     

Spontaneous and assisted restoration of vegetation on the bottom of a former water reservoir,the Elwha River,Olympic National Park,WA, U.S.A.

Early seral vegetation was studied on a former lake bottom after the removal of the 64‐m‐tall Glines Canyon Dam on the Elwha River. In 2015, vegetation cover of all vascular plant species was determined in 63 plots located on sites that emerged in 2011–2012. The sites had been planted and/or seeded, or were permitted to revegetate spontaneously. The plots were further classified by substrate texture: coarse sediments on the valley bottom and fine ones on the valley slopes. Plots were located randomly along random transects perpendicular to the former lake shore that extended into coarse sediment terraces perched above the floodplain. Additionally, 32 plots were sampled in surrounding native forests near these transects. Data were analyzed by detrended correspondence analysis and by canonical correspondence analysis. Substrate texture, that is whether fine or coarse, appeared to explain most of the variability in vegetation. The distance to forest and successional age, that is time since the site had been drained, were also significant explanatory variables, while assisted restoration by planting and seeding appeared to be insignificant to date. Spontaneous succession on fine sediments led to a species composition approaching that of adjacent natural forests. Invasive species were much less abundant than expected. Spontaneous restoration of vegetation on fine sediments in drained lake bottoms can rapidly produce a desirable vegetation composition and structure. On coarse sediments, active restoration may be useful to accelerate the development of native vegetation communities.     

宁南山区不同植被恢复方式下土壤线虫群落特征:形态学鉴定与高通量测序法比较

线虫是土壤食物网的重要组分, 也是土壤健康与生态系统恢复的重要指示生物, 因此准确测定线虫群落特征是发挥其生态指示作用的基础。传统线虫学研究多采用形态学鉴定方法, 但高通量测序技术近年来也逐渐受到重视。然而, 关于这两种方法的对比研究目前仍比较缺乏。本研究同时采用形态学鉴定和高通量测序法, 在黄土高原宁夏南部山区, 对不同植被恢复方式下(农田、自然恢复草地、柠条(Caragana korshinskii)人工林地和苜蓿人工草地)土壤线虫的数量、群落格局和生态指数进行了测定和比较。结果表明: (1)高通量测序仅能提供线虫类群的相对多度, 而形态学鉴定法能够测定土壤线虫的绝对多度, 后者测定结果表明3种植被恢复样地, 特别是自然恢复草地和柠条人工林地, 较农田具有更高的土壤线虫多度; (2)高通量测序法检获的线虫类群数(3纲4目26科42属)高于形态学鉴定法的测定结果(2纲3目18科27属), 但两种方法仅检获15个共有线虫属, 前者检测到的植物寄生线虫属数(22属)较后者(7属)显著增加, 而食细菌线虫和杂食-捕食线虫则相反; (3)在两种方法下, 相比农田, 3种植被恢复样地尤其是自然恢复草地和柠条人工林地, 其食微线虫的相对多度均显著下降, 而植物寄生线虫和杂食-捕食线虫的相对多度大幅上升, 这也导致线虫成熟度指数(MI)和植物寄生线虫指数(PPI)的提高及瓦斯乐卡指数(WI)的显著下降; (4)相比形态学鉴定法, 高通量测序法能检测到更丰富多样的植物寄生线虫, 在该方法下土壤线虫群落的组成、结构和生态指数在植被恢复样地与农田之间的差异也更为显著。综上所述, 采用形态学鉴定和高通量测序法测定的不同植被恢复方式下的线虫群落特征具有显著差异。     

氮磷养分共同添加促进退化典型草原恢复的机制

土壤养分含量降低是我国草原退化的主要原因之一,养分添加是退化草原恢复的有效措施,但过量养分添加会导致物种多样性降低。为了探讨适宜的养分添加量以及养分添加促进退化草原恢复的机制,本研究选择内蒙古典型草原的退化群落,通过氮(N)磷(P)养分共同添加梯度试验,研究了退化典型草原在群落、功能群和物种3个组织水平上对养分添加的响应。结果表明: 在群落水平,养分添加显著促进了退化典型草原生物量,但没有降低物种多样性;群落生物量随养分添加水平表现为饱和曲线响应,在12.0 g N·m^-2、3.8 g P·m^-2水平趋于饱和;物种多样性在低养分添加水平(N<9.6 g·m^-2、P<3.0 g·m^-2)较对照显著增加,在其余养分添加水平未发生显著变化。在功能群水平,随着养分添加量的增加,多年生根茎禾草在群落中优势度增加,生物量和密度均显著提高;一年生植物生物量和密度在高养分水平添加下显著增加,多年生丛生禾草和杂类草无显著变化。在物种水平,6个物种对养分添加响应不同,羊草通过增加种群密度和个体大小显著增加了种群生物量;大针茅、冰草和糙隐子草种群生物量没有显著变化;星毛委陵菜和黄囊苔草分别因为降低个体大小和种群密度减少了种群生物量。养分添加作为草原恢复的措施,可以显著增加退化草原生物量和物种多样性,降低植物群落中退化指示种,增加多年生根茎禾草。     

呼伦贝尔沙地不同植被恢复模式对土壤固氮微生物多样性的影响

利用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术及扩增产物序列分析方法,研究了经过4年不同植被恢复模式下呼伦贝尔沙地土壤固氮微生物的nifH基因多样性和群落结构的变化.结果表明:不同植被恢复模式间土壤固氮微生物群落组成差异显著.混播柠条+羊柴+冰草+披碱草模式(ACHE)下的土壤固氮微生物nifH基因多样性指数最高,其次为混播柠条+冰草(AC)、单播柠条(UC)、单播冰草(UA)和单播羊柴(UH)模式,对照(裸地)最低.除单播羊柴(UH)模式与对照的多样性指数差异不显著外,其余4种植被恢复模式均显著高于对照.单一恢复模式(UA、UH、UC)下,绝大多数土壤固氮微生物属于蓝藻门,结构比较单一;而混播模式(AC和ACHE)下,土壤固氮微生物组成发生明显变化,以变形菌门为主,还包含蓝藻门,其种类增加,多样性提高.不同植被恢复模式的速效磷(AP)、全磷(TP)、全氮(TN)和硝态氮(N03-N)对固氮微生物区系的影响均达到显著水平,且AP、TP、TN和NO3--N之间均具有显著相关性.不同植被恢复模式下土壤固氮微生物区系组成的变化是不同理化因子之间相互关联、共同影响的结果.     

Ecological research for the restoration and management of rivers and reservoirs in Japan

In Japan the River Law was amended in 1997 to expand the traditional roles of flood control and water supply in river management to include environmental conservation. Two major multidisciplinary research groups were also founded to address the environmental issues arising from the management of rivers and watershed areas in Japan. One called the River Ecology Research Group was formed in 1995 to search for an ideal dynamic state of rivers to be managed. Six case studies commenced involving measurements of natural and human impacts on representative rivers and their biota selected from different regions of the country. Restoration of natural rivers has also been attempted. The other, called the Watershed Ecology Research Group, was formed in 1998 to study the natural environment surrounding dams. It consists of four groups concerned with forest ecology in the headwaters, raptor management research, reservoir ecology, and flow regime research. The topics include modeling of regeneration dynamics of riparian forests, GIS mapping of endangered raptor habitats, developing measures to reduce eutrophication of reservoir water, and the use of biodiversity of benthic faunas as an indicator of environmental change in the downstream. In both groups, ecologists collaborate with engineers who are responsible for the river infrastructure, to predict future impacts and keep ecological perspectives for the maintenance of the healthy environment of rivers and reservoirs.     

Environment and landscape rather than planting design are the drivers of success in long‐term restoration of riparian Atlantic forest

Question

Identifying the factors that lead to the success of restoration projects has been a major challenge in ecological restoration. Here we ask which factors, aside from time since restoration began, drive the recovery of tree biomass, density and richness of the understorey in riparian forests undergoing restoration.

Location

Semideciduous Atlantic Forest with tropical climate and deep, fertile soils, southeast Brazil.

Methods

We sampled tree basal area (DBH ≥ 5 cm), density and richness of the understorey (DBH < 5 cm) in 26 riparian forests undergoing restoration (a chronosequence spanning 4–53 years). We assessed the following variables as possible factors, besides time, influencing community attributes: (1) planting design: density and richness of seedlings planted; (2) landscape features: proximity index measuring forest cover within a 1.5‐km radius, distance and size of the nearest forest remnant; and (3) environmental factors: invasive grasses, soil fertility, drought, average annual precipitation and proportion of fine particles in the soil. We performed correlation analyses including predictor and response variables, followed by stepwise backward regression (AIC), multiple and simple linear regressions, to investigate the relationships between those factors and the community attributes.

Results

Tree basal area was primarily influenced by the proportion of small particles in the soil (+) and secondarily by rainfall (?). Understorey richness was influenced by the combination of size (+) and distance (?) of the nearest patch, rainfall (?) and soil fertility (+). Understorey density was primarily influenced by the size of the nearest forest remnant (+) and secondarily by invasive grasses (?). No influence of density or richness of the seedlings planted was observed.

Conclusion

Environmental factors and landscape configuration drive the recovery of tree biomass, density and richness in communities undergoing restoration. The most relevant ecological filters influencing restoration success are availability of soil water and nutrients and the distance and size of the nearest remnant of native vegetation. The expected influence of richness and density of seedlings planted, considered for many years as important drivers of forest restoration success, was not confirmed in this study.     

Restoration for variability: emergence of the habitat diversity paradigm in terrestrial ecosystem restoration

Ecosystem restoration implies focusing on multiple trophic levels and ecosystem functioning, yet higher trophic levels, that is, animals, are less frequently targeted by restoration than plants. Habitat diversity, the spatial heterogeneity between and within habitat patches in a landscape, is a well‐known driver of species diversity, and offers possible ways to increase species diversity at multiple trophic levels. We argue that habitat diversity is central in whole‐ecosystem restoration as we review its importance, provide a practical definition for its components, and propose ways to target it in restoration. Restoration targeting habitat diversity is used commonly in aquatic ecosystems, mostly to increase the physical diversity of habitats, meant to provide more niches available to a higher number of animal species. To facilitate the uptake of habitat diversity in terrestrial ecosystem restoration, we distinguish between compositional and structural habitat diversity, because different animal groups will respond to different aspects of habitat diversity. We also propose four methods to increase habitat diversity: varying the starting conditions to obtain divergent successional pathways, emulating natural disturbances, establishing keystone structures, and applying ecosystem engineer species. We provide two case studies to illustrate how these components and methods can be incorporated in restoration. We conclude that targeting habitat diversity is a promising way to restore habitats for a multitude of species of animals and plants, and that it should become mainstream in restoration ecology and practice. We encourage the restoration community to consider compositional and structural habitat diversity and to specifically target habitat diversity in ecosystem restoration.