Dynamic responses of aboveground biomass and soil organic matter content to grassland restoration

基于1983年开始的改良恢复长期观测试验, 研究了在排除干扰的围封保护下, 不同恢复改良措施对内蒙古退化羊草(Leymus chinensis)草原群落地上生物量和土壤有机质含量动态变化过程的影响, 改良恢复措施包括浅耕翻、耙地和自然恢复。结果表明: (1)地上生物量在前期(1983-1991年)的动态变化特征为自然恢复处理显著低于浅耕翻处理, 耙地处理与其余两个处理没有显著差异。中期(1992-2006年)各处理之间无显著差异; 后期(2007-2014年)为自然恢复>耙地>浅耕翻, 且自然恢复与浅耕翻处理之间有显著差异。(2) 0-10 cm土壤有机质含量在前期的动态变化特征为浅耕翻>耙地>自然恢复, 且处理之间有显著差异, 自然恢复、浅耕翻、耙地处理相对1983年土壤有机质分别增加了21%、45%、37%; 中期和后期自然恢复处理显著大于浅耕翻处理, 耙地处理介于两个处理之间且与二者没有显著差异。中期自然恢复、浅耕翻、耙地处理有机质含量相对1983年分别增加了61%、46%、57%, 后期分别增加了67%、51%、62%。(3) 10-30 cm土壤有机质在前期浅耕翻>自然恢复>耙地, 且各处理之间有显著差异; 中期和后期各处理之间无显著差异。总之, 应依据恢复目标的不同, 选择不同的改良措施。在短时间尺度上, 浅耕翻有利于退化羊草草原生产力和土壤有机碳的快速恢复, 而长时间尺度上自然恢复和耙地的效益更明显。     

切根和浅耕翻措施对退化草地生长季土壤性质及植物群落的影响

草地退化是我国主要生态问题之一,研究草地不同改良措施的生态效应对于科学有效地恢复草地生态系统具有重要意义。以切根、浅耕翻两种典型改良措施为对象,在内蒙古锡林郭勒盟毛登草原内蒙古大学生态学研究基地研究了两种改良措施对土壤硝化速率、羊草群落植物生物多样性和生物量的影响。结果表明:与对照相比,浅耕翻措施显著降低了土壤硝化速率(P0.05),切根措施对土壤硝化速率有提高效果,且土壤硝化速率呈现出明显的时间动态,土壤硝化速率6月份显著最高、9月份显著最低;浅耕翻措施显著降低了羊草群落植物多样性和生物量(P0.05),而切根处理则显著提高了羊草群落植物多样性(P0.05),切根处理对植物生物量提高有作用但效果不显著。研究结果表明不同草地恢复措施显著影响了土壤性质和植物群落,在短期内,浅耕翻措施不是草地恢复的有效措施,而切根处理有助于提高退化草地生物多样性。     

不同改良方法对盐碱土壤磷素营养的影响

采用浅耕翻、施用磷石膏、施用糠醛渣、施用有机肥、建植星星草人工草地或星星草+羊草人工草地等不同改良方法对盐碱土壤磷素营养影响的研究结果表明, 不同改良方法能不同程度的提高土壤全磷、速效磷、有机磷、无机磷含量和磷酸酶活性, 其中浅耕+有机肥+星星草+羊草处理与浅耕相比土壤磷素各指标增加显著, 盐碱土壤磷素营养各指标间存在着一定的相关关系。     

不同改良方法对盐碱土壤氮素营养状况的影响

采用浅耕翻、施用磷石膏、施用糠醛渣、施用有机肥、建植星星草人工草地或星星草+羊草人工草地等不同改良方法对盐碱土壤氮素营养影响的研究结果表明,不同改良方法与浅耕翻相比能不同程度地提高土壤全氮含量、碱解氮含量、氨化强度、固氮强度、蛋白酶活性、脲酶活性、硝酸还原酶活性和亚硝酸还原酶活性。其中,浅耕+有机肥+星星草+羊草处理对所测定盐碱土壤氮素营养及相关酶活性指标增加明显,同时,盐碱土壤氮素营养各指标间存在着一定的相关关系。     

不同改良方法对盐碱土壤腐殖质及几种酶活性的影响

采用浅耕翻、施用磷石膏、施用糠醛渣、施用有机肥、建植星星草人工草地或星星草+羊草人工草地等不同改良方法对盐碱土壤腐殖质及酶活性的研究结果表明,不同改良方法能不同程度的提高土壤腐殖质含量及多酚氧化酶、纤维素酶、过氧化氢酶、过氧化物酶活性。同时,土壤腐殖质含量与纤维素酶活性、纤维素酶活性与过氧化氢酶活性间有很好的相关性。     

恢复措施对退化草地羊草种群有性生殖数量特征的影响

在封育和翻耙处理的退化羊草草地上,对羊草种群有性生殖的数量特征进行了比较研究．结果表明,翻耙样地羊草种群密度下降显著,生殖蘖密度变化不显著,生殖蘖穗长、节间长、生殖生长比率、穗节数、小穗数、小花数、饱满籽实数和结实率都有显著增长,籽实产量、净籽实重和千粒重分别是封育样地的2．68、3．49和1．3倍．在翻耙样地中,羊草种群发育有复小穗的生殖蘖比封育样地多16％,生殖蘖上复小穗的数量也显著增加,生殖蘖以相对少的小穗,生产了较多的小花和更多的籽实来提高种群的籽实产量．两个样地中羊草种群的生物量生殖分配在种群对生殖蘖RA1、生殖蘖对穗序RA4、穗序对籽实RA6 3个层次上无显著差异,而种群对穗序RA2、生殖蘖对籽实RA5的生殖分配差异显著,种群对籽实RA3的生殖分配差异极显著．     

不同土地管理方式对黑土土壤微生物量碳和酶活性的影响

在中国科学院海伦农业生态实验站长期定位试验区,对比研究了黑土自然恢复、休闲裸地和种植作物3种管理方式对0～10、20～30和40～50cm深度土壤的微生物量碳和脲酶、磷酸酶、过氧化氢酶和转化酶活性的影响．结果表明：0～10cm表层土壤的微生物量碳和土壤酶活性均表现为自然恢复〉种植作物〉休闲裸地处理,而20～30cm和40～50cm深度土壤的微生物量碳和土壤酶活性虽也存在差异,但不如表层土壤变化显著．自然恢复和种植作物处理的土壤微生物量碳和土壤酶活性均随土层深度增加而降低,而休闲裸地处理的土壤微生物量碳和脲酶、磷酸酶、过氧化氢酶活性却以20～30cm土层为高．相关分析表明,土壤全碳和全氮、土壤全碳和微生物量碳、土壤微生物量碳和4种土壤酶活性之间都存在极显著的正相关关系．土壤酶活性和土壤微生物量碳两项指标表明在自然恢复条件下黑土土壤质量较好．     

陕北风沙区不同植被覆盖下的土壤养分特征

选取了陕北定边县板凳滩风沙区四种典型植被覆盖下的风沙土壤,对其基本养分含量进行了测定。分析不同类型植被覆盖下的土壤养分含量特征、土壤养分含量层次特征以及土壤各层次养分含量之间的相关性,为风沙区土壤生态恢复重建及侵蚀土壤质量的恢复保育提供了科学依据。结果表明:(1)不同植被覆盖下的土壤对有机质、全氮、速效氮、速效磷的保持能力均为:小蒿草>羊草>沙蒿>苦豆子>无植被;对全磷的保持能力,各植被覆盖条件下差异不显著,但小蒿草覆盖下含量最高,羊草最低,且低于无植被;从土壤对全钾的保持能力来看,羊草覆盖下的全钾含量最高,小蒿草最低。(2)不同植被覆盖下的土壤养分含量层次变化除全磷和全钾变化微弱外,土壤有机质、全氮、速效氮、速效磷、速效钾含量均随着土层深度的增加而逐渐下降,且降低速度基本呈现出小蒿草>羊草>沙蒿>苦豆子>无植被。(3)不同植被覆盖下的土壤各层次养分含量之间的相关性以羊草最为密切,大体呈显著中度及以上正相关;沙蒿和苦豆子覆盖下的相关性稍弱,基本呈中度正相关;而小蒿草覆盖下的相关系数正负均有,相关性较为复杂。     

松嫩平原碱化草甸恢复演替系列的群落种子流分析

对松嫩平原碱化草甸恢复演替系列4个群落优势种种子源库、土壤种子库及幼苗库进行了比较,建立了种子流模型.结果表明:演替初期虎尾草群落优势种种子源库密度最大,为(446182±180455)粒.m-2,分别是演替中期星星草群落的7.2倍、演替后期星星草 羊草群落的11.4倍、演替顶极羊草群落的164.8倍.土壤种子库和幼苗库密度均以虎尾草群落最大,分别为(63650±14541)粒.m-2和(39160±15192)株.m-2,羊草群落最小,分别为(14310±7686)粒.m-2和(790±745)株.m-2,大体呈随着恢复演替进程而递减的趋势.全体演替系列群落输出的实生苗均以虎尾草为主,占79.8%～100%.在种子流中,优势种的种子源库向土壤种子库输入率在10%～35%之间,输出率差异则较大,虎尾草群落高达62.3%,但星星草群落和羊草群落均没有优势种的幼苗输出.     

石羊河下游盐渍化弃耕地植被演替与土壤养分相关性分析

以石羊河下游不同年代盐渍化弃耕地自然群落为对象,利用优势种群的消长和土壤养分的动态变化进行相关性分析,研究退耕地群落演替与土壤养分之间的动态变化以及相互关系。结果表明:1)植被类型一般经历3个阶段:田间杂草→荒漠草本→荒漠灌木,但群落演替可分为4个阶段:藜+田旋花群落(1～2年)→骆驼蒿群落(3～10年)→苏枸杞+黄毛头群落(10～40年)→黄毛头群落(顶极群落);2)土壤养分在整个植被演替过程中一般经历消耗-积累-消耗3个阶段,但速效钾不存在初期消耗阶段,演替后期土壤养分处于消耗状态,并逐渐接近本区域自然植被土壤养分;3)由于前期土壤养分处于消耗阶段,骆驼蒿种群对土壤养分的贡献不明显,其中与速效磷之间呈显著负相关,与速效钾呈显著正相关;苏枸杞种群与土壤养分呈正相关,其中与有机质、全氮、30～60cm速效钾相关性显著;而黄毛头种群与土壤养分之间呈显著负相关。黄毛头具有较强的适应性,可作为盐渍化弃耕地上的适宜引种物种,以调控和加速植物群落演替。     

The effect of river restoration on fish,macroinvertebrates and aquatic macrophytes: A meta-analysis

An increasing number of rivers have been restored over the past decades and several studies investigated the effect on biota. The published monitoring results have already been summarized in narrative reviews but there are few quantitative reviews and a comprehensive meta-analysis on different organism groups and factors influencing restoration effect is missing. We compiled monitoring results and information on catchment, river and project characteristics from peer-reviewed literature and unpublished databases to (i) quantify the effect of restoration measures on fish, macroinvertebrates and macrophytes, and (ii) identify predictors which influence restoration effect. Results indicated significant effects of restoration on all three organism groups, especially of widening projects on macrophyte richness/diversity, instream measures on fish and macroinvertebrates, and higher effects on abundance/biomass compared to richness/diversity. Restoration effect was most strongly affected by agricultural land use, river width and project age. Effects were smaller but restoration generally still increased richness/diversity and abundance/biomass in agricultural catchments. Since land use is a proxy for different pressures, the underlying causal relationships have to be investigated in more detail. Project age was the most important factor but had non-linear and even negative effects on restoration outcome, indicating that restoration effects may vanish over time. The meta-analysis indicated that river managers in general can expect an increase of richness/diversity and abundance/biomass of all three organism groups investigated, especially of macrophytes in widening projects and of fish and macroinvertebrates if instream measures are applied. However, variability was high, stressing the need for adaptive management approaches. Furthermore, the large but non-linear and different (even negative) effects of project age stressed the need for long-time monitoring to better understand the trajectories of change caused by restoration measures and to identify sustainable measures. The meta-analysis was restricted to metrics commonly reported in literature and future studies would greatly benefit from authorities and scientists reporting original monitoring data, which would allow to use functional metrics to investigate the effect of restoration measures and to infer causal relationships.     

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.     

Biological Traits Successfully Predict the Effects of Restoration Management on Macroinvertebrates in Shallow Softwater Lakes

Many shallow softwater lakes are being affected by eutrophication and acidification. In these small lakes decaying organic material usually accumulates and characteristic plant and animal species disappear. In many degraded lakes organic matter and macrophytes are being removed in order to restore the lakes to their original state. To assess the effects of restoration management in softwater lakes on aquatic macroinvertebrates, changes in the species assemblages were studied in four degraded lakes in the Netherlands undergoing restoration measures. The degraded lakes still harboured species characteristic of pristine softwaters. However, most of these species were not recorded after restoration measures were taken. Species’ densities declined dramatically during the execution of restoration measures. Swimming and abundant species were more likely to survive the restoration measures than other species. The first years after restoration, the lakes did not meet the habitat requirements for a number of species. Species requiring vegetation for ovipositioning, animal food sources and swards of vegetation as habitat declined. Because recolonization is expected to be restricted, it is recommended to ensure the survival of relict populations when taking measures to restore degraded softwater lakes. This may be achieved by phasing restoration measures in space and time, hereby minimizing mortality during the execution of restoration measures and by preserving habitat conditions required by characteristic species.     

Phytoplankton Composition and Abundance in Restored Maltański Reservoir under the Influence of Physico-Chemical Variables and Zooplankton Grazing Pressure

In this paper we present the effects of environmental factors and zooplankton food pressure on phytoplankton in the restored man-made Maltański Reservoir (MR). Two methods of restoration: biomanipulation and phosphorus inactivation have been applied in the reservoir. Nine taxonomical groups of phytoplankton represented in total by 183 taxa were stated there. The richest groups in respect of taxa number were green algae, cyanobacteria and diatoms. The diatoms, cryptophytes, chrysophytes, cyanobacteria, green algae and euglenophytes dominated in terms of abundance and/or biomass. There were significant changes among environmental parameters resulting from restoration measures which influenced the phytoplankton populations in the reservoir. These measures led to a decrease of phosphorus concentration due to its chemical inactivation and enhanced zooplankton grazing as a result of planktivorous fish stocking. The aim of the study is to analyse the reaction of phytoplankton to the restoration measures and, most importantly, to determine the extent to which the qualitative and quantitative composition of phytoplankton depends on variables changing under the influence of restoration in comparison with other environmental variables. We stated that application of restoration methods did cause significant changes in phytoplankton community structure. The abundance of most phytoplankton taxa was negatively correlated with large zooplankton filter feeders, and positively with zooplankton predators and concentrations of ammonium nitrogen and partly of phosphates. However, restoration was insufficient in the case of decreasing phytoplankton abundance. The effects of restoration treatments were of less importance for the abundance of phytoplankton than parameters that were independent of the restoration. This was due to the continuous inflow of large loads of nutrients from the area of the river catchment.     

Restoration of riverine inland sand dune complexes: implications for the conservation of wild bees

1.  The evaluation of restoration measures is an important task of conservation biology. Inland sand dunes and dry, oligotrophic grasslands have become rare habitat types in large parts of Central Europe and their restoration and management is of major importance for the preservation of many endangered plant and insect species. Within such habitats, it is important to restore key ecosystem services, such as pollination networks. As wild bees are the most important pollinators in many ecosystems, they represent a suitable key group to evaluate restoration measures. Furthermore, the recent decline of many bee species and the potential ecological and economic consequences are currently topics of strong scientific interest.
2.  We studied the succession of bee communities in response to restoration measures of sand dunes and sand grasslands and compared these communities with those of old sand dune complexes.
3.  Our results show that wild bees respond rapidly to restoration measures indicated by a high species richness and abundance. The community structure of bees at restoration sites converged only slightly to those of the target sites. A higher similarity was found between bee communities at the restoration sites (sand dunes and grasslands), indicating that their close proximity was an important determinant of species overlap. Environmental factors such as the number of entomophilous plant species and moisture had a strong influence on wild bee species composition.
4.   Synthesis and applications . The restoration of inland sand dune complexes provides opportunities for colonization by a diverse wild bee community. Although it is difficult to establish a given target community, restoration measures gave rise to a high pollinator diversity and abundance, suggesting that community function can be re-established.     

Do restoration measures rehabilitate fauna diversity in raised bogs? A comparative study on aquatic macroinvertebrates

To assess whether raised bog restorationmeasures contribute to the conservation andrestoration of the fauna diversity,macroinvertebrate species assemblages werecompared between water bodies created byrewetting measures and water bodies whichhave not been subject to restorationmeasures, but are remnants offormer peat cuttings and trenches used forbuckwheat culture in the past.The restoration sites were inhabited bycharacteristic raised bog species and rarespecies, but their numbers were higher atthe remnant sites not affected byrestoration management. A considerablenumber of characteristic and rare faunaspecies were only found at the remnantsites. The remnant sites includedconsiderably more variation inmacroinvertebrate species assemblages andhad a higher cumulative species richness.The number of characteristicmacroinvertebrate species was not clearlyrelated to the presence of a characteristicraised bog vegetation. In restoration sitesnumbers of rare and characteristic speciesper site tended to increase with the timeelapsed after rewetting. However,restoration measures will not automaticallyresult in restoration of a more or lesscomplete macroinvertebrate speciesspectrum, as restoration measures have sofar resulted in habitats for only a limitednumber of the characteristic species.When planning restoration measures, it isrecommended to protect the populations ofrare and characteristic species present inthe area, as these populations may becomethe sources for colonization of rewettedsites. Safeguarding habitat diversityduring the restoration process andrestoration of different elements of thehabitat diversity of complete raised bogsystems will result in the characteristicfauna diversity being conserved andrestored more successfully.     

Towards a Conceptual Framework for Restoration Ecology

Heightening human impacts on the Earth result in widespread losses of production and conservation values and make large-scale ecosystem restoration increasingly urgent. Tackling this problem requires the development of general guiding principles for restoration so that we can move away from the ad hoc, site- and situation-specific approach that now prevails. A continuum of restoration efforts can be recognized, ranging from restoration of localized highly degraded sites to restoration of entire landscapes for production and/or conservation reasons. We emphasize the importance of developing restoration methodologies that are applicable at the landscape scale. Key processes in restoration include identifying and dealing with the processes leading to degradation in the first place, determining realistic goals and measures of success, developing methods for implementing the goals and incorporating them into land-management and planning strategies, and monitoring the restoration and assessing its success. Few of these procedures are currently incorporated in many restoration projects. The concept that many ecosystems are likely to exist in alternative stable states, depending on their history, is relevant to the setting of restoration goals. A range of measures, such as those being developed to measure ecosystem health, could be used to develop “scorecards” for restoration efforts. Generalizable guidelines for restoration on individual sites could be based on the concepts of designed disturbance, controlled colonization, and controlled species performance. Fewer explicit guidelines are available at the landscape scale, beyond nonquantitative generalities about size and connectivity. Development of these guidelines is an important priority so that urgent large-scale restoration can be planned and implemented effectively.     

祁连山山水林田湖草生态保护与修复的探索与实践

遵循“山水林田湖草是一个生命共同体”的先进理念,实施生态系统的整体保护、系统修复、综合治理,是加强生态文明建设的新举措。现阶段生态保护与修复的研究主要集中在内涵、机制及启示等方面,为“山水林田湖草”生态保护修复提供了理论与技术支撑,但缺乏系统性的梳理与总结。以中国重要生态功能区祁连山为例,以生态地位、退化现象及成因为切入点,结合已开展的生态保护修复工程,总结了典型生态保护修复措施,提出了有针对性的策略与建议,旨在为山水林田湖草生态修复提供模式示范。祁连山生态退化的原因主要为：全球气候变暖、人类活动干预、传统发展理念制约及环境保护投入不足等。典型生态保护与修复措施已涵盖了“山水林田湖草”各个方面,但在工程实践中如何有机整合各项措施,使生态系统成为“生命共同体”仍是未来探索的科学问题。生态保护修复的理论与实践还需完善以下内容：加强基础调研与科技创新;加强统一规划与协同管理;积极完善生态补偿机制;建立由“开刀治病”工程治理向“健康管理”自然恢复逐步引导的生态修复理念。     

喀斯特地区石漠化生态修复对土壤生物多样性的影响

我国西南喀斯特地区是具有土层薄和土被不连续等特征的生态脆弱区,人为过度干扰和土地不当利用导致了生境退化甚至石漠化的发生。从“九五”规划到“十三五”规划,为了有效抑制并逆转石漠化趋势,生态修复措施得到普遍的推广应用。“十四五”规划进一步提出科学推进石漠化综合治理,提高生态系统自我修复能力和稳定性。从土壤微生物、原生动物、线虫、微节肢动物、蚯蚓和线蚓等方面,综述了喀斯特地区生态修复对土壤生物多样性的影响。研究发现：(1)喀斯特生境细菌和真菌的多样性高于非喀斯特生境,原因是喀斯特具有较高的土壤pH和钙含量;(2)与非喀斯特生境相比,喀斯特生境土壤动物类群数相差不大而个体密度较低;(3)石漠化过程伴随着植被退化,降低了土壤微生物种类和功能多样性,土壤动物的个体密度和类群数也呈现降低趋势;(4)生态修复促进植被正向演替,土壤微生物量和酶类活性逐渐上升,真菌/细菌生物量比值增大,土壤动物个体密度和类群数增加,有利于土壤固碳和生态修复。因此,土壤生物多样性是适合指示喀斯特石漠化的生态修复的生物学指标。研究建议：(1)在传统分类鉴定基础上,结合宏基因组学、宏蛋白质组学和同位素标记等技术,完善生态修复的...