Long‐term effects of drainage and initial effects of hydrological restoration on rich fen vegetation

Questions: What vegetational changes does a boreal rich fen (alkaline fen) undergo during a time period of 24 years after drainage? How is plant species richness affected, and what are the changes in composition of ecological groups of species? Is it possible to recover parts of the original flora by rewetting the rich fen? Which are the initial vegetation changes in the flora after rewetting? What are the major challenges for restoration of rich fen flora after rewetting? Location: Eastern central Sweden, southern boreal vegetational zone. Previously rich fen site, drained for forestry purposes during 1978–1979. The site was hydrologically restored (rewetted) in 2002. Method: Annual vegetation survey in permanent plots during a period of 28 years. Results: There were three successional stages in the vegetational changes. In the first stage there was a rapid (< 5 years) loss of rich fen bryophytes. The second step was an increase of sedges and early successional bryophytes, which was followed by an increase of a few emerging dominants, such as Molinia caerulea, Betula pubescens and Sphagnum spp. After rewetting, there are indications of vegetation recovery, albeit at slow rates. Depending on, for instance, initial species composition different routes of vegetation change were observed in the flora after drainage, although after 24 years, species composition became more homogenous and dominated by a few species with high cover. Conclusion: Major changes have occurred after changes in the hydrology (drainage and rewetting) with a severe impact on the biodiversity among vascular plants and bryophytes. Several rich fen bryophytes respond quickly to the changes in water level (in contrast to vascular plants). The recovery after rewetting towards the original rich fen vegetation is slow, as delayed by substrate degradation, dispersal limitation and presence of dominant species.     

土壤纤毛虫群落对退牧还草生态恢复的响应——以玛曲县为例

为研究退牧还草对土壤纤毛虫群落特征的影响、退牧还草后土壤环境变化以及如何利用原生动物纤毛虫群落特征来评价退还效果的可行性,于2015年5月至2016年3月在甘肃省甘南藏族自治州玛曲县选取3个不同恢复年限的草地样点和1个未经过退牧还草对照样点,采用"非淹没培养皿法"、活体观察法和培养直接计数法对土壤纤毛虫的物种数和密度进行测定,同时测定了土壤温度、pH值、含水量、土壤孔隙度、速效钾、速效氮、速效磷、全氮、全钾、全磷和有机质含量,并分析了在生态逐渐恢复条件下,土壤纤毛虫群落特征与土壤环境因子间的相关性。研究共鉴定到纤毛虫95种,隶属9纲15目21科28属。研究发现,退牧还草样地与未退牧还草样地的土壤纤毛虫的物种分布存在明显差异:退牧还草后的3个样点间的物种相似性减小,群落组成复杂化,纤毛虫丰度、丰富度指数、均匀度指数和物种多样性指数增高。相关性分析结果表明,退牧还草后,对纤毛虫群落结构稳定性影响最主要的是土壤有机质、含水量和土壤全氮、全磷和全钾的含量,不同恢复年限样点的土壤纤毛虫群落组成差异较大。土壤纤毛虫群落对退牧还草生态恢复过程中土壤环境条件的变化有较好的响应。     

Restoration of upland hay meadows over an 11‐year chronosequence: an evaluation of the success of green hay transfer

Grassland restoration has become a key tool in addressing the drastic losses of seminatural grassland since the mid‐twentieth century. This study examined the restoration by green hay transfer of upland hay meadows, a particularly scarce and vulnerable habitat, over an 11‐year chronosequence. The community composition of 18 restoration meadows was compared with that of donor reference sites in two study areas in the Pennine region of northern England. The study investigated: differences in community composition between donor and restoration meadows; transfer of upland hay meadow target species; and the effect of time and isolation from neighboring meadows on the community composition of the restoration meadows. Results showed that restoration meadows differed from donor meadows in that some target species were easily transferred whilst others were not found in the restoration meadows, or were at low levels of cover. Time had a significant effect on the community composition of the restoration meadows, but the similarity between restoration sites and donor sites did not increase with time, and the effect of isolation was not significant. The study showed that the green hay transfer method increases botanical diversity and is an important first step in meadow restoration. However, further restoration activity, such as seed addition, is likely to be required if restoration sites are to resemble closely the reference donor sites.     

Strengths and potential pitfalls of hay transfer for ecological restoration revealed by RAD‐seq analysis in floodplain Arabis species

Achieving high intraspecific genetic diversity is a critical goal in ecological restoration as it increases the adaptive potential and long‐term resilience of populations. Thus, we investigated genetic diversity within and between pristine sites in a fossil floodplain and compared it to sites restored by hay transfer between 1997 and 2014. RAD‐seq genotyping revealed that the stenoecious floodplain species Arabis nemorensis is co‐occurring with individuals that, based on ploidy, ITS‐sequencing and morphology, probably belong to the close relative Arabis sagittata, which has a documented preference for dry calcareous grasslands but has not been reported in floodplain meadows. We show that hay transfer maintains genetic diversity for both species. Additionally, in A. sagittata, transfer from multiple genetically isolated pristine sites resulted in restored sites with increased diversity and admixed local genotypes. In A. nemorensis, transfer did not create novel admixture dynamics because genetic diversity between pristine sites was less differentiated. Thus, the effects of hay transfer on genetic diversity also depend on the genetic make‐up of the donor communities of each species, especially when local material is mixed. Our results demonstrate the efficiency of hay transfer for habitat restoration and emphasize the importance of prerestoration characterization of microgeographic patterns of intraspecific diversity of the community to guarantee that restoration practices reach their goal, that is maximize the adaptive potential of the entire restored plant community. Overlooking these patterns may alter the balance between species in the community. Additionally, our comparison of summary statistics obtained from de novo‐ and reference‐based RAD‐seq pipelines shows that the genomic impact of restoration can be reliably monitored in species lacking prior genomic knowledge.     

The effects of different vegetation restoration patterns on soil bacterial diversity for sandy land in Hulunbeier

Grassland desertification seriously threatens sustainable economic and social development. Much attention has been paid to the control of grassland desertification, and even to the restoration and reconstruction of the grassland. Vegetation restoration is considered to be a very effective solution. Soil sustains an immense diversity of microbes, and the characteristics of soil microbial communities are sensitive indicators of soil. It is important to understand the relationship between vegetation and soil microbial diversity during the restoration process. Soil microbial, which is the main index to evaluate soil quality, plays a significant role in ecosystem and soil microbial diversity is the important one of global diversity. Exploring the effects of different vegetation patterns on soil microbial diversity can provide scientific bases and technical support for systemic and impersonal assessment of the best vegetation restoration patterns, as well as the vegetation restoration and reconstruction of Hulunbeier sandy land. Based on PCR–DGGE technology, a case study was carried out to investigate the effects of five different vegetation restoration patterns on soil microbial functional diversity after 4 years in sandy land in Hulunbeier, China. The five vegetation restoration patterns included mono-cultivar planting of Agropyron cristatum (UA), mono-cultivar planting of Hedysarum fruticosum (UH), mono-cultivar planting of Caragana korshinskii (UC), mixed-cultivar planting of Agropyron cristatum and Hedysarum fruticosum (AC) and mixed-cultivar planting of Agropyron cristatum, Hedysarum fruticosum, Caragana korshinskii and Elymus nutans (ACHE). Completely degraded sandy land was used as control.The results indicated that the vegetation restoration increased the genetic diversity of soil bacterial community obviously, and the structure of soil bacterial community was changed. The results of phylogenetic analysis suggested that the bacterial community in Hulunbeier sandy land mainly attributed to Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, and Acidobacteria. The dominant groups were Proteobacteria and Bacteroidetes. The effects of different vegetation type on soil bacterial community structures were different.     

The influence of seed addition and cutting regime on the success of grassland restoration on former arable land

Questions: Can seed addition enhance the success of establishing species‐rich grassland on former arable land? Are sowing date and cutting regime important in determining success? Location: Aberdeen and Elgin, northeast Scotland, United Kingdom. Methods: A field experiment was conducted at two sites to assess the effect of seed addition, sowing date and cutting regime on the vegetation developing on former arable land, the aim being to compare the success of different treatments at producing a species‐rich grassland. Results: Sowing a seed mix resulted in the establishment of vegetation very distinct from the species‐poor vegetation dominated by perennial grasses which otherwise developed, though establishment success of the sown grassland species was highly variable between sites. Where establishment of the sown species was poor, sowing date had no significant effect on species composition, whereas the cutting regime was very important. Cutting the vegetation significantly increased both the number and abundance of sown species compared with the uncut control. Conversely, where establishment had been good, the cutting regime in the first year had little effect on species composition. Cutting the vegetation at least twice a year appeared to be the most effective management over the length of the experiment. Conclusions: Sowing a seed mixture significantly reduced the abundance and number of naturally colonising species, effectively controlling problem weed species such as Senecio jacobaea and Cirsium vulgare, highlighting the agronomic value of sowing seed mixtures on fallow farmland. The sowing of a seed mix on former arable land has demonstrated that it is feasible to create vegetation similar in character to that of species‐rich grasslands.     

太岳山油松林火烧迹地恢复初期植物群落结构特征

为研究山西太岳山油松（Pinus tabuliformis）林过火后恢复初期林下草本植物群落结构,以2019年3月太岳山油松林火烧迹地为研究对象,采用群落相似性指数、多样性指数、稳定性系数、TWINSPAN数量分类和DCA排序等方法对群落组成、多样性、类型及稳定性等进行了研究。结果表明：（1）火烧迹地恢复初期以低矮灌木和多年生草本植物为主,其中又以地面芽植物占比最大。优势植物主要为大披针薹草（Carex lanceolata）和多花胡枝子（Lespedeza floribunda）;（2）火烧迹地恢复初期各样地植物群落相似性系数和多样性指数相对较小,均匀度指数较大,但各样地恢复效果不尽相同,样地6和样地7的植物群落各项指标相对大于其他样地;（3）TWINSPAN数量分类将火烧迹地植物群落划分成：I.大披针薹草+南牡蒿（Artemisia eriopoda）+地榆（Sanguisorba officinalis）群丛、II.多花胡枝子+大披针薹草+二色棘豆（Oxytropis bicolor）群丛、III.多花胡枝子+大披针薹草+米口袋（Gueldenstaedtia verna）群丛、IV.多花胡枝子+大披针薹草+荠苨（Adenophora trachelioides）群丛、V.大披针薹草+白莲蒿（Artemisia stechmanniana）+狗娃花（Aster hispidus）群丛、VI.白莲蒿群丛、VII.大披针薹草+狗娃花+野艾蒿（Artemisia lavandulifolia）群丛;（4）DCA排序结果表明,火烧迹地恢复初期植物群落结构单一,沿样地和坡位变化较小,仅区分出样地7和其他样地两大类植物群落。（5）火烧迹地恢复初期植物群落处于不稳定的状态,但各样地间群落稳定性存在一定差别,其中样地1最大,样地5最小。总之,研究区植物群落处于演替初期,各样地间植物群落稳定性较差,多样性和整体相似性较小,但优势种群相似性较高,植物群落结构仍处于动态变化之中。研究揭示了太岳山火烧迹地恢复初期植物群落结构特征,积累了该区域火烧迹地植物群落生态学数据,同时可为该区域生态恢复提供科学依据。     

The importance of long‐term social‐ecological research for the future of restoration ecology

In the face of rapid environmental and cultural change, long‐term ecological research (LTER) and social‐ecological research (LTSER) are more important than ever. LTER contributes disproportionately to ecology and policy, evidenced by the greater proportion of LTER in higher impact journals and the disproportionate representation of LTER in reports informing policymaking. Historical evidence has played a significant role in restoration projects and it will continue to guide restoration into the future, but its use is often hampered by lack of information, leading to considerable uncertainties. By facilitating the storage and retrieval of historical information, LTSER will prove valuable for future restoration.     

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.     

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.     

Mid‐term effects on ecosystem services of quarry restoration with Technosols under Mediterranean conditions: 10‐year impacts on soil organic carbon and vegetation development

The use of Technosols for the restoration of limestone quarries overcomes the usual “in situ” scarcity of soil and/or its poor quality. The use of mine spoils, improved with mineral and/or organic amendments, could be an efficient and environmentally friendly option. Properly treated sewage sludge from urban wastewater treatment plants could be a suitable organic amendment and fertilizer (rich in N and P) whenever its pollutant burden is low (heavy metals and/or organic pollutants). Its appropriate use could improve essential soil physical and chemical properties and, therefore, promote key ecosystem services of restored areas, such as biomass production and carbon sequestration, as well as biodiversity and landscape recovery. However, the mid‐term impacts of these restoration practices on soil functioning and their services have rarely been reported in the available literature. In this study we assess the mid‐term effects (10 years) of the use of sewage sludge as a Technosol amendment on soil organic carbon (SOC), nutrient status, and plant development in several restored quarries. Soils restored using sewage sludge showed a threefold increase in SOC compared to the corresponding unamended ones, despite the moderate sludge dosage applied (below 50 tonnes/ha). Plant cover was also higher in amended soils, and recruitment was not affected by sludge amendment at these doses. This study demonstrates that, used at an appropriate rate, sewage sludge is a good alternative for the valorization of mine spoils in quarry restoration, improving some important regulatory ecosystem services such as carbon sequestration, without compromising woody plant encroachment.     

Social perspectives on the use of reference conditions in restoration of fire‐adapted forest landscapes

As approaches to ecological restoration become increasingly large scale and collaborative, there is a need to better understand social aspects of restoration and how they influence land management. In this article, we examine social perspectives that influence the determination of ecological reference conditions in restoration. Our analysis is based on in‐depth interviews with diverse stakeholders involved in collaborative restoration of fire‐adapted forest landscapes. We conducted interviews with 86 respondents from six forest collaboratives that are part of the U.S. Forest Service's Collaborative Forest Landscape Restoration Program. Collaboratives use a variety of approaches to develop reference conditions, including historic, contemporary, and future scenarios. Historical conditions prior to European settlement (nineteenth century or “pre‐settlement” conditions), or prior to more recent grazing, logging, and exclusion of fire, were the predominant type of reference used in all sites. Stakeholders described benefits and limitations of reference conditions. Primary benefits include (1) providing a science‐based framework for bringing stakeholders together around a common vision; (2) gaining social understanding and acceptance of the underlying need for restoration; and (3) serving to neutralize otherwise value‐laden discussions about multiple, sometimes competing, resource objectives. Limitations stem from (1) concerns over social conflict when reference conditions are perceived to contradict other stakeholder values and interests, (2) differing interpretations of reference condition science, (3) inappropriate application or over‐generalization of reference information, and (4) limited relevance of historical references for current and future conditions in some ecosystems. At the same time, collaboratives are adopting innovative strategies to address conceptual and methodological limitations of reference conditions.     

The influence of different grazing regimes on Phragmites‐ and shrub vegetation in the well‐drained zone of a eutrophic wetland

Abstract. The effects of grazing by cattle and horses on vegetation development were studied in the well‐drained border zone of the Oostvaardersplassen nature reserve, a managed eutrophic wetland in the young Zuidelijk Flevoland polder in The Netherlands. At the start of the study period, 12 yr after the area was enclosed by dykes, the vegetation was dominated by Phragmites australis and tall herbs, particularly Cirsium arvense. Over the next 8 yr, different plant communities developed under different grazing regimes. In all communities, C. arvense was gradually replaced by Urtica dioica, and stands dominated by these two species expanded at the expense of P. australis. The shrub Sambucus nigra invaded the stands of C. arvense and U. dioica. Grazing affected the rate of these developments and the degree to which the grass Poa trivialis became dominant. When cattle were enclosed at a relatively high stocking rate in an area of Phragmites australis and tall herbaceous vegetation during summer, P. trivialis became dominant within 4 yr. The introduction of herbivores led to a faster spread of S. nigra, which contains cyanogenic glycosides which only ruminants can detoxify. Horses, as hind‐gut fermenters, did not feed on S. nigra. Grazing pressure and herbivore species, therefore, are two important variables that can be used to manage the development of Phragmites‐ and shrub vegetation: the greater the grazing pressure by cattle or horses the greater the area dominated by grasses, and a relatively high grazing pressure by cattle will retard S. nigra expansion.     

基于规划目标的京津风沙源治理区生态保护与修复效应

为改善和优化京津及周边地区生态环境状况,减轻风沙危害,2003年启动实施了京津风沙源治理工程。基于工程规划目标评估了京津风沙源治理区生态保护与修复效应,结果表明:(1)草地和林地作为京津风沙源治理区绿色生态屏障的主要组成,分别占治理区面积的57.3%和9.7%,而风沙策源地的耕地和沙地分别占17.2%和6.4%。(2)2003—2017年,京津风沙源治理区草地、耕地、沙地面积减少,而林地和其他类型面积增加。治理区植被覆盖度平均提高了2.3%,其中林地提高了4.3%,草地提高了2.4%。(3)沙尘天气发生的春季,治理区土壤风蚀量减少了54%。在防风固沙服务总量的贡献中,草地和沙地贡献了71%。因此,草地和沙地生态系统的植被恢复,对治理区生态系统防风固沙服务的提高发挥了最为重要的作用。(4)除治理区植被有所恢复外,由于气候整体变暖,近15年风场强度有所减弱,特别是沙尘天气易发生的春季风场强度减弱近45%,也是影响京津风沙源治理区风蚀量下降的一个重要原因。     

Possible domestic dispersal of Bactrocera dorsalis during 2015 occurrence on the small islands of south‐western Japan

Although Japan has maintained the state of eradication of the oriental fruit fly, Bactrocera dorsalis Hendel complex (Diptera: Tephritidae) since 1986, B. dorsalis complex are occasionally trapped within a limited area and short time period on Japan's small south‐western islands. Trapping events occurred on Amamioshima Island, Kagoshima Prefecture, in 2015, and male adults were also caught in surveillance traps on neighbouring Tokunoshima (south of Amamioshima) and Yakushima (north of Amamioshima) islands as well as on several islands in Okinawa Prefecture (south of Amamioshima). To investigate possible domestic dispersal of the pest from Amamioshima Island, a trajectory analysis was performed to reveal the timing and flight distance of possible dispersal. Surveillance data indicated that the first trappings on Tokunoshima and Yakushima islands occurred in November, which was after the number of trapped male adults on Amamioshima Island peaked in late October. Backward trajectories from Tokunoshima Island beginning 14 days prior to the first trapping passed over Amamioshima Island, which suggested possible dispersal between the islands. Several backward trajectories from the islands in Okinawa Prefecture also passed Amamioshima Island. Moreover, forward trajectories from Amamioshima Island beginning during peak occurrence, from mid‐October to early November, arrived over Tokunoshima, Iheya and Okinawa islands where the flies were caught. Such circumstantial evidence suggests that domestic dispersal of B. dorsalis complex occurred on Amamioshima Island. A situation similar to that on Tokunoshima Island also occurred on Yakushima Island. However, since the number of traps has been limited until the first capture, it was not clear when and from where the immigrants arrived on the island.     

Long‐term after‐effects of fertilisation on the restoration of calcareous grasslands

Question: What are the long‐term implications of former fertilisation for the ecological restoration of calcareous grasslands? Location: Gerendal, Limburg, The Netherlands. Methods: In 1970, ten permanent plots were established in just abandoned agricultural calcareous grassland under a regime of annual mowing in August. From 1971 to 1979, two different fertiliser treatments were applied twice a year to a subset of the plots (artificial fertiliser with different proportions of nitrogen and phosphorus). The vegetation of the plots was recorded yearly and vegetation biomass samples were taken for peak standing crop and total amounts of nitrogen, phosphorus and potassium. Species composition and floristic diversity were analysed over the research period (1970–2006) and between the treatments, including the use of multivariate techniques (Detrended Correspondence Analysis). Results: In terms of species number, there is a clear optimum 10 to 20 years after fertilisation has been terminated. Afterwards, there is a slow decrease; no new species appear and species of more nutrient‐rich conditions gradually disappear. For the fertilised plots that received a relatively high proportion of N, effects are found only in the first years, whereas, for the plots that received a relatively high proportion of P, long‐term after‐effects are found in species composition, peak standing crop, total amounts of phosphorus in biomass, and in soil phosphorus data. Conclusions: The effect of artificial fertiliser with a large amount of nitrogen disappears in less than ten years when mown in August, including removal of the hay. This is a promising result for restoration of N‐enriched calcareous grasslands, as the applied dose of nitrogen in this experiment largely exceeds the extra input of nitrogen via atmospheric deposition. Application of fertiliser with a large amount of phosphorus, however, has effects even more than 25 years after the last addition. There are no prospects that this effect will become reduced in the near future under the current mowing management.     

植被恢复十年喀斯特坡地细根对土壤碳氮存留与可利用性的影响

土壤碳氮存留与可利用性对恢复生态系统的稳定性和可持续性产生重要影响,研究其细根控制过程对深入理解植被恢复的作用及其针对性应用具有重要意义。依托中国科学院环江喀斯特生态系统观测研究站10年植被恢复平台,通过分析8种植被恢复模式植物（细根生物量、δ¹³C、δ¹⁵N）、土壤（有机碳、总氮、δ¹³C、δ¹⁵N、团聚体、砂粒、交换性钙、可溶性有机碳和氮、铵态氮、无机氮、微生物生物量碳和氮）理化性质的变化和关系,阐明细根对土壤碳氮存留与可利用性的影响。研究结果表明：细根对土壤碳氮存留的影响可能主要基于对土壤团聚体结构的改善,加强了对土壤原有机碳、氮的保护和存留,而细根有机质输入的影响是较弱的;细根可能通过影响微生物调控土壤可利用性碳和氮;因高的细根生物量和固氮植物,封育林和刈割草地模式具有较高的土壤碳氮存留效应。综上所述,喀斯特植被恢复过程中细根对土壤碳氮存留与可利用性产生积极的影响。因此,石漠化生态工程治理可以考虑根系发达与固氮植物共同引种。