Evaluation of natural forest regeneration as a part of land restoration in the Khentii massif,Mongolia

Forest stands in the semi-arid environment of northern Mongolia have an essential role in controlling ongoing desertification in the surrounding landscape.Over the last decade,the total forest area has decreased dramatically.The aim of this study was to evaluate the potential of natural regeneration as an essential element for ensuring sustainability of these forests.Based on field measurements from 120 plots in six sites,our assessment tool revealed five qualitative categories of forest regeneration,allowing us to assess impacts of both grazing and environmental conditions on the regeneration process.Grazing is a crucial factor and adversely affects regeneration.For sites with relatively low grazing intensity,low soil moisture levels represent the main reason for reduced regeneration.The approach to classification proposed in this study allows for the identification and interpretation of stand conditions where natural regeneration has failed.This study provides an important foundation to inform decisionmaking related to land protection and restoration actions.Our findings could be used in comparative studies and,importantly,may aid further mapping of Mongolian forests.

Does forest restoration influence soil infiltrability? A case study in the restored woodland of Sierra de ávila(Central Spain)

Infiltration,as a major component of the hydrological cycle,plays an important role in ecosystems,river flooding,and soil erosion.Therefore,this process has been studied on different soils,with different vegetation cover,and under different climate conditions.However,it is still necessary to know how infiltration rates depend on land degradation,vegetation cover,forest management,and forest restoration,since soil infiltration is related to soil hydrological function and hydrological ecosystem services.The aim of our study is to analyze the way reforestation and check dam construction have helped to improve soil infiltration rates in comparison with old,degraded land,different soils and vegetation covers in Central Spain.Therefore,three infiltration tests were carried out by means of a simple methacrylate infiltrometer ring,in four sampling plots,for five types of land use:(i) native holm oak forest,(ii) 60-year-old reforested pine wood,(iii) shrubs,(iv) sediment wedges of check dams,and(v) gullies and degraded hillslopes.Our results show much higher infiltration rates in the soil of 60-yearold pine reforestation sites(1198.00 mm·h^(-1)),and in the sediment wedges of check dams(1088.00 mm·h^(-1)),than in those of degraded hillslopes(365.00 mm·h^(-1)) and shrubland(420.80 mm·h^(-1)).The rates were also shown to be close to those from the remaining patches of native holm oak woodland(770.40 mm·h^(-1)).We also found that organic matter,humus and litter depth,and height of vegetation and cover,all improve soil infiltration rates,while slope degree,presence of coarse elements,stoniness,clay content,bulk density,and electric conductivity inhibit the rates.It was additionally seen that pine reforestation and check dam construction caused degraded land to recover its hydrological conditions to a level that is quite close to that of the ancient oak holm native forest,alongside ameliorating the hydrological cycle in the watershed.This information will be very useful for decisionmaking processes related to land restoration projects,forest management,and environmental policy.

Effects of restoration modes on the spatial distribution of soil physical properties after land consolidation: a multifractal analysis

Soil physical properties(SPP)are considered to be important indices that reflect soil structure,hydrological conditions and soil quality.It is of substantial interest to study the spatial distribution of SPP owing to the high spatial variability caused by land consolidation under various land restoration modes in excavated farmland in the loess hilly area of China.In our study,three land restoration modes were selected including natural restoration land(NR),alfalfa land(AL)and maize land(ML).Soil texture composition,including the contents of clay,silt and sand,field capacity(FC),saturated conductivity(Ks)and bulk density(BD)were determined using a multifractal analysis.SPP were found to possess variable characteristics,although land consolidation destroyed the soil structure and decreased the spatial autocorrelation.Furthermore,SPP varied with land restoration and could be illustrated by the multifractal parameters of D1,ΔD,ΔαandΔf in different modes of land restoration.Owing to multiple compaction from large machinery in the surface soil,soil particles were fine-grained and increased the spatial variability in soil texture composition under all the land restoration modes.Plough numbers and vegetative root characteristics had the most significant impacts on the improvement in SPP,which resulted in the best spatial distribution characteristics of SPP found in ML compared with those in AL and NR.In addition,compared with ML,Δαvalues of NR and AL were 4.9-and 3.0-fold that of FC,respectively,andΔαvalues of NR and AL were 2.3-and 1.5-fold higher than those of Ks,respectively.These results indicate that SPP can be rapidly improved by increasing plough numbers and planting vegetation types after land consolidation.Thus,we conclude that ML is an optimal land restoration mode that results in favorable conditions to rapidly improve SPP.

Impacts of land disturbance and restoration on runoff production and sediment yield in the Chinese Loess Plateau

Land disturbance and land restoration are important factors influencing runoff production and sediment yield in the semi-arid loess regions of China. This study compared the runoff production and sediment yield during the early stage after land disturbance（ESLD） with those during restoring stage after land disturbance（RSLD）. Grey relational analysis was used to analyse the importance of each one of the influencing factors（vegetation, rainfall, soil and topography） in affecting the runoff production and sediment yield. Our results showed that during ESLD, topography was the most critical factor controlling the runoff production, while soil was the most important factor controlling the sediment yield. During RSLD, vegetation was more important in affecting runoff production, while rainfall was more important in affecting sediment yield. In additional, this study demonstrated that both the runoff production and the sediment yield can be effectively reduced by restoring vegetation on severely-disturbed lands, thus providing an important theoretical basis for better implementations of the Grain for Green Program. Our results revealed that the vegetation types of Hippophae rhamnoides＋Pinus tabulaeformis and H. rhamnoides are better plant selections for land restoration in this area, especially for relatively gentle slopes（i.e., less than 20 degrees）.

Restoration technologies of damaged paddy in hilly post-mining and subsidence-stable area of Southwest China

The paddy fields and water storage facilities are seriously damaged by the coal mine subsiding in the hilly post-mining and subsidence-stable areas in China,which make the farmers there being suffered greatly from the lack of water for traditional rice cultivation and daily life.The purpose of this paper is to find a method to restore the damaged paddy fields,thereby promoting sustainable development of land resources,and alleviating the contradiction between people and land,as well as creating a more inhabitable environment.The research methodology included field experiments,cultivated observation,and field investigation.This paper selected the Songzao Mining Area as the research area,and focused on the restoration technologies of damaged paddy fields,through the following four different measures at three experimental fields:(1)Traditional repeated cattle plowing(CK);(2)Water retention agent with repeated cattle plowing(W&C);(3)Film without holes under tilth depth(FO);and(4)Film with holes under tilth depth(FW).At last,a contrastive analysis of the four measures was made according to the results of the experiments.The results show that the use of water retaining agent with repeated cattle plowing(W&C)can be the most appropriate method to restore the damaged paddy field in the hilly post-mining and subsidence-stable area in southwest China.Compared with the other three measures,its water productivity is the maximum(0.81 kg/m3),and the net income is the highest(1403$/hm^(2)).What’s more,it is simple,short time-consuming,and low cost,which is benefit to generalize the use of this restoration technology.

Vegetation and ecosystem carbon recovery following shifting cultivation in MizoramManipur-Kachin rainforest eco-region,Southern Asia

Background:Shifting cultivation(locally known as“jhum”)is a major driver of deforestation and loss of ecosystem services in rainforests.For developing any effective conservation of biodiversity and carbon service program,an indepth understanding to the recovery of vegetation and carbon after abandonment of jhum is essential.We estimated species richness,abundance and composition of trees,shrubs and herbs,carbon distribution in aboveground and belowground components along a chronosequence of jhum fallow in northeast India,and elucidated the factors affecting the recovery processes of jhum fallows.Methods:Species composition and other plant community attributes,carbon storage in different pools were studied in 5 jhum fallows(<5,5-10,11-15,16-20,21-25 years old)and an old-growth forest.The data were subjected to linear mixed effect modeling using R-package“nlme”for identifying the important factors contributing to the recovery of vegetation and carbon.Results:Species composition varied significantly(P<0.05)between jhum fallows and old-growth forest.Tree density varied from 28 stems ha−1 in 5 years old jhum fallow to 163 stems ha−1 in old-growth forest.Both biomass carbon in all components and soil organic carbon were significantly(P=0.01)lower in jhum fallows than in the old-growth forest except living non-woody biomass component.The recovery of aboveground biomass carbon was faster during early successive years than the mid-successive jhum fallows.Total ecosystem carbon and soil organic carbon stock in the oldest jhum fallow was 33%and 62%of those in the old-growth forest,respectively.The fallow age was found to be the most important explanatory factor in the recovery process of vegetation and carbon stock in re-growing fallows.Conclusion:The shifting cultivation fallows gradually recovered both vegetation and carbon and are potential repository sites for biodiversity conservation,which may take much longer time to reach up to old-growth forest in northeast India.