Species diversity variation of Cupressus funebris secondary forest in landslide site after 5.12 Wenchuan Earthquake北大核心CSCD

The characteristics of species diversity in Cupressus funebris secondary forest under the effect of geological hazard were explored by selecting the typical landslide surface of Fenghuang Mountain, Leigu Town, Beichuan County, which was derived from the 5.12 Wenchuan earthquake. The results showed that 93 species belonged to 42 families, and 78 genera were found in the landslide area, where the main families were Compositae, Leguminosae, and Gramineae-based. Further, 97 species in the transition area belonged to 39 families and 80 genera, and the main families were Compositae, Gramineae, and Rosaceae-based. In all, 108 species were recorded in the non-landslide area, which belonged to 59 families and 92 genera, the main families of which were Compositae, Rosaceae, and Gramineae-based. Compositae and Gramineae played important roles in the landslide recovery process after earthquake. The Pielou index (JSW) was the highest in the non-landslide area of the herb layer, whereas the richness index (D) was the lowest; the Shannon-Wiener index (H) and Simpson index (H') showed medium values. In the non-landslide area, the D, H, and H' were the highest in the shrub layer, whereas the JSW was the lowest. Further, the species diversity index of the transitional area was higher than that of the landslide area. In the tree layer, the D and H were both the highest and lowest in the landslide area and transition area, respectively. In contrast, the H' and JSW were the highest in the transition area and the lowest in the non-landslide area. The distribution of vegetation was generally consistent with the distribution of soil nutrients in the spatial distribution of surface soil nutrients. The succession of trees in the landslide area was relatively slow and at the initial stage, and the pioneer species were Coriaria nepalensis, Leptopus chinensis, and Arthraxon lanceolatus in this area. Taken together, the findings suggested that the stability of a plant community can be increased by improving the soil and stabilizing the slope. © 2018 Science Press. All rights reserved.     

Spatial cost–benefit analysis of blue restoration and factors driving net benefits globally

Marine coastal ecosystems, commonly referred to as blue ecosystems, provide valuable services to society but are under increasing threat worldwide due to a variety of drivers, including eutrophication, development, land-use change, land reclamation, and climate change. Ecological restoration is sometimes necessary to facilitate recovery in coastal ecosystems. Blue restoration (i.e., in marine coastal systems) is a developing field, and projects to date have been small scale and expensive, leading to the perception that restoration may not be economically viable. We conducted a global cost–benefit analysis to determine the net benefits of restoring coral reef, mangrove, saltmarsh, and seagrass ecosystems, where the benefit is defined as the monetary value of ecosystem services. We estimated costs from published restoration case studies and used an adjusted-value-transfer method to assign benefit values to these case studies. Benefit values were estimated as the monetary value provided by ecosystem services of the restored habitats. Benefits outweighed costs (i.e., there were positive net benefits) for restoration of all blue ecosystems. Mean benefit:cost ratios for ecosystem restoration were eight to 10 times higher than prior studies of coral reef and seagrass restoration, most likely due to the more recent lower cost estimates we used. Among ecosystems, saltmarsh had the greatest net benefits followed by mangrove; coral reef and seagrass ecosystems had lower net benefits. In general, restoration in nations with middle incomes had higher (eight times higher in coral reefs and 40 times higher in mangroves) net benefits than those with high incomes. Within an ecosystem type, net benefit varied with restoration technique (coral reef and saltmarsh), ecosystem service produced (mangrove and saltmarsh), and project duration (seagrass). These results challenge the perceptions of the low economic viability of blue restoration and should encourage further targeted investment in this field.     

Landscape consequences of aggregation rules for functional equivalence in compensatory mitigation programs

Mitigation and offset programs designed to compensate for ecosystem function losses due to development must balance losses from affected ecosystems with gains in restored ecosystems. Aggregation rules applied to ecosystem functions to assess site equivalence are based on implicit assumptions about the substitutability of functions among sites and can profoundly influence the distribution of restored ecosystem functions on the landscape. We investigated the consequences of rules applied to the aggregation of ecosystem functions for wetland offsets in the Beaverhill watershed in Alberta, Canada. We considered the fate of 3 ecosystem functions: hydrology, water purification, and biodiversity. We set up an affect‐and‐offset algorithm to simulate the effect of aggregation rules on ecosystem function for wetland offsets. Cobenefits and trade‐offs among functions and the constraints posed by the quantity and quality of restorable sites resulted in a redistribution of functions between affected and offset wetlands. Hydrology and water purification functions were positively correlated with one another and negatively correlated with biodiversity function. Weighted‐average rules did not replace functions in proportion to their weights. Rules prioritizing biodiversity function led to more monofunctional wetlands and landscapes. The minimum rule, for which the wetland score was equal to the worst performing function, promoted multifunctional wetlands and landscapes. The maximum rule, for which the wetland score was equal to the best performing function, promoted monofunctional wetlands and multifunctional landscapes. Because of implicit trade‐offs among ecosystem functions, no‐net‐loss objectives for multiple functions should be constructed within a landscape context. Based on our results, we suggest criteria for the design of aggregation rules for no net loss of ecosystem functions within a landscape context include the concepts of substitutability, cobenefits and trade‐offs, landscape constraints, heterogeneity, and the precautionary principle.     

Intraspecific Chromosome Number Variation: a Neglected Threat to the Conservation of Rare Plants

Abstract: The effectiveness of rare plant conservation will increase when life history, demographic, and genetic data are considered simultaneously. Inbreeding depression is a widely recognized genetic concern in rare plant conservation, and the mixing of genetically diverse populations in restoration efforts is a common remedy. Nevertheless, if populations with unrecognized intraspecific chromosome variation are crossed, progeny fitness losses will range from partial to complete sterility, and reintroductions and population augmentation of rare plants may fail. To assess the current state of cytological knowledge of threatened and endangered plants in the continental United States, we searched available resources for chromosome counts. We also reviewed recovery plans to discern whether recovery criteria potentially place listed species at risk by requiring reintroductions or population augmentation in the absence of cytological information. Over half the plants lacked a chromosome count, and when a taxon did have a count it generally originated from a sampling intensity too limited to detect intraspecific chromosome variation. Despite limited past cytological sampling, we found 11 plants with documented intraspecific cytological variation, while 8 others were ambiguous for intraspecific chromosome variation. Nevertheless, only one recovery plan addressed the chromosome differences. Inadequate within‐species cytological characterization, incomplete sampling among listed taxa, and the prevalence of interspecific and intraspecific chromosome variation in listed genera, suggests that other rare plants are likely to have intraspecific chromosome variation. Nearly 90% of all recovery plans called for reintroductions or population augmentation as part of recovery criteria despite the dearth of cytological knowledge. We recommend screening rare plants for intraspecific chromosome variation before reintroductions or population augmentation projects are undertaken to safeguard against inadvertent mixtures of incompatible cytotypes.     

双台子河口湿地植被修复生境健康评价方法研究

以2014—2015年双台子河口滨海湿地植被修复20个站位调查资料为基础,对湿地修复结构指标、功能指标和环境指标进行研究,结合湿地生态系统健康理论,构建湿地生态环境健康评价指标体系。运用层次分析法(AHP)确定权重,对各个指标赋予权重,将健康评价分为3个等级,确立了生态健康评价方法,对近岸破损湿地翅碱蓬修复生境进行评价。进一步引用评价净影响值(EI)方法判断生境修复前、后的健康对比状态,从而确定翅碱蓬对该破损湿地的修复效果显著。从景观生态学和健康评价角度分析来看,建立此评价方法是可行的,可为今后湿地的管理与保护提供科学依据。     

三里洞矸石废弃地人工植被群落构建初探

对矸石土样及植被材料进行采样测定,研究分析矸石的供肥能力、微量有毒元素含量、矿区植物中微量有毒元素的含量。研究结果表明:刺槐(Robinia pseudoacacia)对Cu、As元素吸收能力大于其它植物;荠菜(Capsella bursapastrois)对Zn元素的吸收能力较其他植物强;狗尾草(Setaria viridis)对Cr元素具有较强的吸收能力。依据矸石废弃地立地类型特点,矸石废弃地人工植被景观恢复过程中应选择臭椿(Ailanthus altissima)、刺槐(Robinia pseudoacacia)作为先锋树种,宜优先选用刺槐×沙棘×荠菜(Robinia pseudoacacia×Hippophae rhamnoides×Capsella)、刺槐×沙棘×狗尾草(Robinia pseudoacacia×Hippophae rhamnoides×Setariaviridis)、臭椿×沙棘×狗尾草(Ailanthusaltissima×Hippophae rhamnoides×Setaria viridis)群落与刺槐林、臭椿林配植模式。运用生态恢复的方法对矸石废弃地进行人工植被景观恢复与重建,恢复其受损伤的生态系统,这对矸石废弃地植被恢复有一定的理论指导意义。     

通辽露天煤矿排土场恢复初期土壤碳组分变化及影响因素

通过研究露天煤矿排土场植被恢复初期土壤碳的变化规律及相关的影响因素,可为矿区排土场生态恢复提供科学依据和决策支持。为此,以内蒙古通辽高寒露天煤矿排土场土壤为研究对象,分别在2018、2019和2020年植物复垦土壤以及2021年未复垦土壤进行调查取样,探究了恢复初期土壤全碳、有机质、颗粒有机碳(POC)、矿物结合态有机物 (MAOC)和土壤微生物量碳(MBC)变化规律及影响因素。结果表明：植被复垦后土壤碳组分显著高于对照土壤,并随着排土场植被恢复时间的增加,土壤活性有机质中的POC、MAOC组分以及MBC的含量显著增加,但土壤全碳含量的差异不显著。土壤pH显著影响土壤全碳和MAOC含量,而土壤铵态氮与土壤碳累积呈负相关。随着植被恢复时间的增加,土壤pH降低,并与土壤全碳和MAOC的含量显著增加显著相关。因此,植被恢复对于排土场土壤碳累积具有重要的意义,同时在排土场生态恢复的过程中应重视土壤盐碱化治理。     

浅议郴州市废弃矿山生态恢复途径

郴州市矿产资源丰富,采矿业发达,矿山资源开发导致了环境污染、生态破坏等一系列问题,矿山废弃地的生态恢复及景观重建已成为郴州市经济和社会发展需要迫切解决的问题之一.概括地介绍了郴州市的基本状况,分析了郴州市采矿业的无序发展对生态环境的影响,并针对矿山废弃地环境的污染问题,探索性地提出了郴州市废弃矿山生态恢复的途径.