Salt-marsh restoration: evaluating the success of de-embankments in north-west Europe

De-embankment of historically reclaimed salt marshes has become a widespread option for re-creating salt marshes, but to date little information exists on the success of de-embankments. One reason is the absence of pre-defined targets, impeding the measurement of success. In this review, success has been measured as a saturation index, where the presence of target plant species in a restoration site is expressed as a percentage of a regional target species pool. This review is intended to evaluate and compare success of many different sites on an idealistic concept where all regional target species have the potential to establish in a site, but may not actually do so because the site is unsuitable or inaccessible. Factors affecting suitability and accessibility and management options to increase regional species diversity are discussed. The results show that many sites contain less than 50% of the regional target species, especially when sites are smaller than 30 ha. Higher species diversity is observed for sites exceeding 100 ha and for sites with the largest elevational range within mean high water neap to mean high water spring tide. Most sites younger than 20 years contain more target species than older sites. For future de-embankments it is recommended that clear targets are set from the start. This brings along the need for monitoring. Only 37 out of 70 sites with de-embankment were monitored for plant species assemblages. Setting targets will also allow adaptive management of the site. Management options that are likely to result in higher species diversity are the construction and maintenance of drainage structures and the implementation of a grazing or mowing regime.     

中国红壤丘陵区基于突变模型的生态恢复措施下土壤恢复评价

Current methods that utilize simple data or models to evaluate soil restoration under ecological restoration are not sufficiently rigorous.Soil restoration under ecological restoration measures was evaluated in the red soil hilly region of China by applying the catastrophe model.Among 89 soil sites selected,26 (29.21％) were in the middle lobe,10 (11.24％) in the upper lobe,and 53 (70.79％) in the lower lobe of the process surface in the Cusp catastrophe model.The catastrophic direction of the 26 unstable soil sites was to the upper lobe of the process surface according to vegetation cover change and fieldwork.There was a significant negative correlation of the variation in bifurcation set (△ value) with vegetation cover increase,and a higher vegetation cover increase was related to higher unstable probability.The four ecological restoration measures were listed in the order:low-quality forest improvement (LQFI) ＞ arbor-bush-herb mixed plantation (ABHMP) ＞ orchard improvement (OI) ＞ closing measures (CM) according to the proportions of unstable soil sites,which were all higher than no restoration measure,while they were in the order:LQFI ＜ ABHMP ＜ OI ＜ CM according to their △ values,which were all lower than those of no restoration measure.Farmers' assessment of soil restoration under the four ecological restoration measures was in accordance with the proportions of unstable soil sites and inversely proportional to the △ value.Therefore,farmers' assessment can prove the evaluation of soil restoration under ecological restoration measures based on catastrophe model.     

On the restoration of high diversity forests: 30 years of experience in the Brazilian Atlantic Forest

We present a review of more than 30 years of ecological restoration in the Brazilian part of the Atlantic Forest. Based on what has been done in this biome, we try to summarize the main findings and challenges for restoration in this highly threatened forest biome. We found that many past experiences did not result in self-perpetuating forests, for different reasons. Currently, most projects aim to construct self-sustaining communities and no longer see restoration as a deterministic process. We also found that the reconstruction of permanent forest with high diversity is feasible but it depends on the strategies applied and on the surrounding landscape. Although many new techniques have been created (e.g. seed rain management or promotion of natural regeneration), the most used one in the Atlantic Forest is still the planting of many native species from different functional groups. Native species are largely used and perform well even in highly disturbed environments. Today, many projects are trying to produce thousands of hectares of permanent forests and many technical advances are about to be incorporated. But restoration also faces some main challenges to become an effective and widespread means of conserving the Atlantic Forest which are, namely, reducing costs, planning restoration actions at landscape-level, and conforming to socio-political issues. The socio-political tools to overcome such barriers in practice have yet to be developed.     

黄土高原子午岭地区植被恢复过程中的土壤质量评价

选择黄土高原子午岭地区植被自然恢复1-140a不同年限的阳坡墚坡地为研究对象,通过相关性分析筛选土壤表层（0-20cm）16项表征土壤物理、化学、生物学性质的指标,运用主成分分析计算土壤质量综合指数,评价子午岭地区植被恢复过程对土壤质量的影响。结果表明：土壤总孔隙度、平均重量直径（MWD）、有机质质量分数、速效磷质量分数、蔗糖酶活性、碱性磷酸酶活性、真菌数量、微生物总量构成土壤质量评价指标体系;土壤质量综合指数随植被恢复年限的增加而增加;植被自然恢复1-140a间,土壤质量综合指数变化范围为0.1559-0.8509,较裸露休闲地增加4.2-27.5倍;根据土壤质量综合指数变化规律,可将140a植被恢复过程中的土壤质量演变过程分为3个阶段,即植被恢复初期（1-20a）的土壤质量综合指数呈快速增长,植被恢复中期（20-40a）的土壤质量综合指数呈波动性增长,植被恢复后期（40-140a）的土壤质量综合指数呈稳定增长。植被演替过程中不同植被生活型土壤质量综合指数表现为乔木林地〉灌木林地〉草地。     

Changes in the waterbird community of the Lake Sevan-Lake Gilli area, Republic of Armenia: a case for restoration

Waterbird species richness (Gaviiformes, Podicipediformes, Pelecaniformes, Ciconiiformes, Phoenicopteriformes, Falconiformes, Anseriformes, Gruiformes, Charadriiformes, Passeriformes) has been significantly affected by a 19.5 m lowering of the water level in Lake Sevan (1933-2000), and the complete draining of nearby Lake Gilli (1960-2000) in the Republic of Armenia. Twenty-three former breeders are currently nonbreeders in the area. Four former breeders (black stork Ciconia nigra, glossy ibis Plegadis falcinellus, white-winged scoter Melanitta fusca, little crake Porzana parva) have been extirpated from the area. Four former nonbreeders (cattle egret Bubulcus ibis, red-breasted goose Branta ruficollis, sociable lapwing Chettusia gregaria, lesser black-backed gull Larus fuscus) have been absent from the area for at least 20 years. The red-breasted merganser Mergus serrator is the only former nonbreeder discovered breeding in the Lake Sevan basin. We recommend that management plans of the 1960s and 1970s be used to further develop and enact new efforts to increase the water level of Lake Sevan by at least 6 m, and that Lake Gilli and its surrounding wetlands be restored as a means of increasing waterbird species richness overall, and protecting regional populations of globally threatened or near-threatened species (Dalmatian pelican Pelecanus crispus, red-breasted goose Branta ruficollis, ferruginous pochard Aythya nyroca, white-headed duck Oxyura leucocephala, corn crake Crex crex, great snipe Gallinago media, black-winged pratincole Glareola nordmanni, white-tailed eagle Haliaeetus albicilla).     

黄土丘陵沟壑区退耕地自然恢复植被特征及其与土壤环境的关系

 为给黄土高原退耕地的植被恢复和重建提供科学依据,以黄土高原丘陵沟壑区的安塞县为例,用系统聚类和逐步多元回归的分析方法,对退耕地自然恢复植被的演替阶段进行划分,并定量分析群落演替过程中的植被特征及其与土壤环境的关系。结果表明:黄土丘陵沟壑区退耕地自然恢复草地的演替,依次经历猪毛蒿群落→赖草群落→长芒草群落、铁杆蒿群落、达乌里胡枝子群落→白羊草群落。随着退耕地植被恢复的不断进行,Gleason指数、Margalef指数等丰富度指数以及群落Pielou指数,都呈现出先减小后增大的趋势,Simpson指数在演替初期及平衡阶段较大,群落生态优势度与物种丰富度的变化趋势相反。在群落的演替过程中,土壤有机质、全N、有效N和速效K的含量不断增加,土壤pH值和速效P含量不断减小,土壤表层密度变小,孔隙度变大。A层土壤全N、有效N含量、土壤pH值和C层土壤全N含量与物种丰富度呈显著正相关,A、C层土壤有机质含量和B层土壤速效K含量与其关系相反;B层土壤速效P的含量与群落生态优势度呈显著正相关;A、B层土壤速效K含量与植被群落盖度呈正相关关系,B层土壤速效P含量与其关系相反。     

青藏高原高寒草地土壤pH值的大尺度格局及其与气候、土壤因子的关系

Soil acidity is an important parameter that can regulate ecosystem structure and function. However, a quantitative understanding of the relationships between soil pH and environmental factors remains unavailable. In this study, relationships of soil pH with both climatic and edaphic factors in alpine grasslands on the Tibetan Plateau, China were quantified using data obtained from a regional soil survey during 2001-2004. Our results showed that soil pH decreased along the gradient of both mean annual temperature and precipitation. Likewise, soil pH exhibited consistent negative correlations with soil moisture and silt content. However, soil organic and inorganic carbon contents played opposite roles in shaping patterns of soil pH： the accumulation of soil organic matter led to higher soil acidity, while the existence of soil inorganic matter was favorable for maintaining higher soil alkalinity. The variation partitioning analysis indicated that the combination of climatic and edaphic variables explained 74.3% of the variation in soil acidity. These results suggest that soil pH could be predicted from routinely-measured variables, allowing a robust pedotransfer function to be developed. The pedotransfer function may facilitate land surface models to generate more reliable predictions on ecosystem structure and function around the world.     

恢复措施对皆伐油松林团聚体活性有机碳含量的影响——以黄土丘陵区松峪沟流域为例

团聚体中的活性有机碳对土壤质量改善以及碳库动态平衡具有重要意义.为了研究皆伐后土壤团聚体活性有机碳的分布状况,本实验选取黄土高原典型油松林为对象,以未皆伐人工油松林为对照,采用高锰酸钾氧化法研究皆伐后不同恢复植被群落(幼林、撂荒、灌木)地表0 ～ 20 cm层土壤团聚体中活性有机碳变化特征.结果表明:1)研究区土壤以大团聚体(＞ 250 μm)为主,自然恢复的灌木地以及撂荒地大团聚体质量分数显著增加(P＜0.05).2)有机碳质量分数随团聚体粒径的增大而增加,大团聚体是有机碳积累的主要场所,并且自然恢复的灌木地团聚体有机碳质量分数最高.3)研究区油松林团聚体低活性有机碳质量分数＞中活性有机碳质量分数＞高活性有机碳质量分数,大团聚体活性有机碳质量分数大于微团聚体.研究表明,皆伐会造成团聚体有机碳趋于活化,其中自然恢复的灌木地活性有机碳质量分数显著增加.本研究还进一步发现大团聚体中的高活性有机碳能更好地预测土壤碳库变化.     

Prolegomena to sediment and flow connectivity in the landscape: A GIS and field numerical assessment

This paper presents two new definitions of sediment and water flux connectivity (from source through slopes to channels/sinks) with examples of applications to sediment fluxes. The two indices of connectivity are operatively defined, one (IC) that can be calculated in a GIS environment and represents a connectivity assessment based on landscape's information, and another that can be evaluated in the field (FIC) through direct assessment. While IC represent a potential connectivity characteristic of the local landscape, since nothing is used to represent the characteristics of causative events, FIC depend on the intensities of the events that have occurred locally and that have left visible signs in the fields, slopes, etc.IC and FIC are based on recognized major components of hydrological connectivity, such as land use and topographic characteristics. The definitions are based on the fact that the material present at a certain location A reaches another location B with a probability that depends on two components: the amount of material present in A and the route from A to B. The distance to B is weighted by the local gradient and the type of land use that the flow encounters on its route to B, while the amount of material present in A depends on the catchment surface, slope gradient and type of land use of said catchment.Although IC and FIC are independent from each other, and are calculated using different equations and different inputs, they complement each other. In fact, their combined use improves IC's accuracy. Hence, connectivity classes can afterward be rated using IC alone.This procedure has been applied in a medium-size watershed in Tuscany (Italy) with the aim of evaluating connectivity, identifying connected sediment sources and verifying the effects of mitigation measures.The proposed indices can be used for monitoring changes in connectivity in areas with high geomorphological or human induced evolution rates.     

Ecological risks of the use of sewage sludge as fertilizer in soil restoration: effects on the soil microarthropod populations

Experimental plots were laid out in a limestone quarry in Girona (Catalonia, Spain) to test the effects of sewage sludge on the soil microarthropod populations. Two different doses of sludge (7·5 per cent and 15 per cent) were applied to fertilize soil that was used to restore a quarry after opencast mining. Mean annual arthropod density increased when sludge was applied, but the 15 per cent dose caused an impoverishment of the community structure and a decrease of the soil oribatid diversity. Julidae (Diplopoda) and large predators of the mite family Parasitidae (Mesostigmata) were the most depressed taxa, whereas some groups depending on the availability or quality of organic matter (such as the immature Coleoptera or the Uropodidae), or on water availability (such as Collembola) were stimulated. Among the oribatids, Punctoribates sp. was the most depressed, whereas the more common little Oppias were significantly favoured. The application of sludge at a dose of 15 per cent must be avoided in order to preserve the soil biodiversity. Copyright © 1999 John Wiley & Sons, Ltd.     

A field assessment of the role of selective herbicides in the restoration of British moorland dominated by Molinia

Upland heather moors are high priority biotopes for conservation in Britain, but are under threat from a number of sources. One such threat is a change from a vegetation dominated by dwarf shrubs, mainly Calluna vulgaris, to a grassland dominated by Molinia caerulea. Restoration of a dwarf shrub community has proved problematic with studies showing that herbicide use may be necessary to control Molinia. Previously the non-selective herbicide, glyphosate, has been recommended, but this herbicide may damage Calluna and other moorland species severely. Here, we tested a range of selective herbicides (graminicides) for use in an herbicide-based conservation strategy under field conditions. Two selective herbicides, propaquizafop and quizalofop-ethyl, gave a short-term check to Molinia and another, cycloxydim, provided a reduction for at least 1 year, but this effect disappeared after 3 years. Damage to Calluna was less than that caused by glyphosate, and the selective herbicides had little effect on other moorland species present. Our findings suggest that selective herbicides have a potential role in reducing Molinia during moorland restoration, although follow-up applications, and appropriate moorland management, will also be needed.     

An assessment of potential pesticide transmission,considering the combined impact of soil texture and pesticide properties: A meta-analysis

Pesticides are widely employed as a cost-effective means of reducing the impacts of undesirable plants and animals. The aim of this paper is to develop a risk ranking of transmission of key pesticides through soil to waterways, taking into account physico-chemical properties of the pesticides (soil half-life and water solubility), soil permeability, and the relationship between adsorption of pesticides and soil texture. This may be used as a screening tool for land managers, as it allows assessment of the potential transmission risks associated with the use of specified pesticides across a spectrum of soil textures. The twenty-eight pesticides examined were differentiated into three groups: herbicides, fungicides and insecticides. The highest risk of pesticide transmission through soils to waterways is associated with soils containing <20% clay or >45% sand. In a small number of cases, the resulting transmission risk is not influenced by soil texture alone. For example, for Phenmedipham, the transmission risk is higher for clay soils than for silt loam. The data generated in this paper may also be used in the identification of critical area sources, which have a high likelihood of pesticide transmission to waterways. Furthermore, they have the potential to be applied to GIS mapping, where the potential transmission risk values of the pesticides can be layered directly onto various soil textures.     

Distribution of Cr,Ni and Co in soils and rocks of Neyriz area (Iran): the influence of ophiolitic formations

Neyriz area, on south of Neyriz ophiolite complex, is one of the most important areas in fruit production. However, no study has been yet performed to assess the contamination status of soils in this region. The objective of the present study was to explore soil pollution by Cr, Ni and Co. Three landforms (ophiolite hills, alluvial fan and playa) were selected along a transect. Seven pedons were excavated and soil and rock samples were obtained. The total concentration of Cr, Ni and Co, Enrichment Factor (EF) and Geo-accumulation index (I_geo) were determined. Results showed that soils over ophiolite hills and alluvial fan were extremely polluted by Cr and Ni (I_geo=3–6). The EF Index confirmed that heavy metals originated from ophiolite rocks in the region. Both indices showed a descending trend from ophiolite hills to playa that related to deposit transportation processes during landforms evolution. It was also observed a decreasing vertical trend in metal contents in the soils over alluvial fan which can be attributed to the long-time irrigation and plant uptake as affected by land use. Further investigation is needed to understand the contamination status of ground-water and orchards of the region to achieve sustainable management.     

Arbuscular mycorrhizal fungi in the Brazilian Atlantic forest: A gradient of environmental restoration

Arbuscular mycorrhizal fungi (AMF) are of great importance for the successful regeneration of degraded natural areas. The objective of this study was to examine how the time of environmental recuperation is affecting the occurrence and diversity of AMF species in riparian areas belonging to the Atlantic Forest biome in the State of São Paulo, Brazil. The study involved a native forest area (NT) and a gradient of environmental restoration: five (R05), ten (R10), and twenty (R20) years after reforestation. Soil samples were collected in the rainy (January) and dry season (June). Chemical, physical and microbiological analyses were performed including the amount of glomalin and quantification of AMF spores. The frequency of occurrence of genera and ecological indices, as richness (R), Shannon's diversity (H) and Simpson's dominance index (Is) were calculated. The largest spore number was found in R05 and the highest richness and diversity indices of AMF species in NT. Considering the two sampling periods and the four areas studied, we found 22 AMF species, and the genera Glomus and Acaulospora were the most frequent. A Canonical Discriminant Analysis showed that Glomus viscosum, Acaulospora scrobiculata, Acaulospora mellea and Scutellospora heterogama were the species that contributed the most to distinguishing the areas. Moisture, density and glomalin were positively correlated with the number of spores, however, soil nitrate showed a negative correlation. This work gives a better understanding of the interactions between AMF and forest soils and allows to know the distribution of AMF species according to environmental recovery time.     

中国土壤学过去30年在一些关键领域的研究进展

Due to continuous decreases in arable land area and continuous population increases,Chinese soil scientists face great challenges in meeting food demands,mitigating adverse environmental impacts,and sustaining or enhancing soil productivity under intensive agriculture.With the aim of promoting the application of soil science knowledge,this paper reviews the achievements of Chinese scientists in soil resource use and management,soil fertility,global change mitigation and soil biology over the last 30 years.During this period,soil resource science has provided essential support for the use and exploitation of Chinese soil resources,and has itself developed through introduction of new theories such as Soil Taxonomy and new technologies such as remote sensing.Soil fertility science has contributed to the alleviation and elimination of impeding physical and chemical factors that constrain availability of essential nutrients and water in soils,the understanding of nutrient cycling in agroecosystems,and the increase in nutrient use efficiency for sustainable crop production.Chinese soil scientists have contributed to the understanding of the cropland’s role in global change,particularly to the understanding of methane and nitrous oxide emission from rice fields and the effect of elevated carbon dioxide and ozone on rice-wheat system.Soil biology research has progressed in biological N fixation,distribution of fauna in Chinese soils,and bioremediation of polluted soils.A new generation of soil scientists has arisen in the last three decades.The gaps between research and application in these soil science fields are also discussed.     

A comparison of the effectiveness of various extractants for determining humus quality in a calcareous soil

Abstract

Humic substances from an Argentinian chesnut (Mollisol) soil were extracted with Na‐Dowex A‐1 resin, 0.1 N NaOH and 0.1 M Na₄P₂O₇ without decalcification and with 0.1 N NaOH after decalcification. Humic to fulvic (Ch/Cf) acid and E₄/E₆ ratios of the extracts were determined and compared.

A simpler and more rapid procedure than the classical ones for extracting and characterizing soil humus is proposed. The procedure is based on the use of a chelating resin as extractant and on the direct determination of analytical properties of humus in aliquots of the extract.     

吉林省粮食生产的农业自然资源利用率研究

用实际产值占光、热、水、土壤资源生产潜力（资源可能产量）的比率作为粮食生产对自然资源的开发利用率，计算了吉林省各市县主要粮豆作物资源利用率现状。粮豆作物光合资源利用率为２０％￣３０％，光温资源利用率为２５％￣４０％，气候资源利用率为３５％￣４５％，气候－土壤资源综合利用率为４５％￣５５％。资源利用率地域差异较明显，中部及东部半山区较高，东部山区次之，西部半干旱区较低。最后，分析了各地粮食增产的潜力     

A comparison of different 15N application techniques to study the N net rhizodeposition in the plant‐soil system

The suitability of three ¹⁵N application methods (¹⁵NH₃ fumigation, split‐root technique, ¹⁵N pre‐cultivation) for the estimation of N net rhizodeposition (NRD) of wheat plants into soil has been tested and compared under similar conditions and at the same developmental stage. The results were as follows: 1. The use of the ¹⁵N tracer technique allows the detection of the net N release by roots under soil conditions. NRD was considerable and can be estimated to be at least 15 kg N ha⁻¹ a⁻¹. 2. All three methods applied are practicable under non‐sterile experimental conditions. The distribution of applied ¹⁵N in the system and NRD can be balanced totally only by using the ¹⁵NH₃ fumigation and the ¹⁵N pre‐cultivation methods. The split‐root technique leads to an overestimation of NRD. 3. The split‐root technique allows a qualitative separation of the NRD under nearly undisturbed conditions. With the ¹⁵N precultivation, a higher ¹⁵N‐labelling can be achieved for long‐term balance studies. 4. Despite the required high ¹⁵N abundance, the ¹⁵NH₃ fumigation method works best to evaluate the influence of microbes on NRD and to quantify the gaseous ¹⁵N release.     

Prospects of sediment deposition at small watershed scale in the black soil region of Northeast China: A mini review

Sediment deposition is one of the most significant processes in small watersheds characterized by gentle long hillslopes in the black soil(Mollisol)region of Northeast China, as indicated by severe ephemeral gully and gully erosion on hillslopes and very low sediment concentrations in river systems.Few reviews have been conducted to summarize the related research in this region. The objectives of this review were to identify the potential factors influencing sediment deposition, review related s...     

Metapopulation dynamics and conservation of the marsh fritillary butterfly: Population viability analysis and management options for a critically endangered species in Western Europe

This study investigates the dynamics and viability of a marsh fritillary butterfly Euphydryas aurinia metapopulation in a Belgian successional landscape. Based on capture-mark-recapture and winter nest census data, we first estimated demography (survival and recruitment rates, population size, density dependence) and dispersal parameters (emigration rate, effect of patch connectivity on dispersal, mortality during dispersal). Then using RAMAS/GIS platform, we parameterised a population viability analysis (PVA) model with these parameters to simulate the future of this metapopulation under different scenarios.The metapopulation does not seem viable even if natural reforestation is controlled by adequate management. In its present state, the patch system is not able to sustain enough individuals: due to the large temporal fluctuations in demographic parameters, a carrying capacity far higher than currently would be necessary to limit extinction risk to 1%, suggesting the existence of an extinction debt for the species in Belgium. The situation of E. aurinia appears much worse compared to two other fritillary species threatened in Belgium, for which similar PVA are available. It is therefore urgent to increase the carrying capacity of the patch system. How and where it is achieved are of secondary importance for the gain in viability: improvement of habitat quality through restoration, or increase of habitat quantity via enlargement of existing patches and/or creation of new habitat in the matrix. A regime of management based on regular re-opening and maintenance of habitat patches may be the only guarantee of long-term persistence for this critically endangered species in Belgium.