In response to the effectiveness of reforestation in controlling soil erosion,there has been a dramatic increase in forest coverage in the hilly red soil region of southern China.Aggregate stability and soil shear str...In response to the effectiveness of reforestation in controlling soil erosion,there has been a dramatic increase in forest coverage in the hilly red soil region of southern China.Aggregate stability and soil shear strength are indicators that reflect soil resistance to erosion and its ability to prevent shallow landslides,respectively.However,limited research has focused on the response of soil aggregate stability and shear strength to reforestation.We selected three types of reforestations(Phyllostachys edulis forest,Cunninghamia lanceolata(Lamb.)Hook.forest,Citrus sinensis(L.)Osbeck.orchard),a natural forest(mixed coniferous and broadleaf forests),and a fallow land as study plots,and measured root traits,and soil physicochemical traits,i.e.,pH,soil organic matter(SOC),Soil water content(SWC),soil bulk density(BD),soil cohesion(c),soil internal friction angle(φ)and analyzed their multiple interactions.The soil aggregate stability traits,refer to the mean weight diameter(MWD)and geometric mean diameter(GMD),exhibited a significant increase in reforested plots,approximately 200%compared to fallow land and 50%compared to natural forests.For soil shear strength the values were approximately 20%higher than in fallow land and approximately 10%lower than in natural forests.Soil aggregate stability and soil shear strength did not exhibit a significant positive correlation across all plots,and the underlying drivers of these traits were variable.For instance,in natural forest and timber stands,soil aggregate stability was mainly influenced by soil organic carbon,while soil shear strength was primarily affected by root length density.In economic forest,aggregate stability and shear strength are mainly affected by organic carbon.Overall,we found that vegetation restoration enhances soil erosion resistance,however,the primary drivers for the improvement of aggregate stability(soil organic carbon)and shear strength(root length density)are different.Therefore,in future benefit assessments of vegetation restoration projects aimed at soil erosion control,different indicators should be considered based on specific conditions.展开更多
To evaluate the long-term effects of reforestation types on soil erosion on degraded land, vegetation and soil properties under conventional sloping farmland （CSF） and three different reforestation types including a...To evaluate the long-term effects of reforestation types on soil erosion on degraded land, vegetation and soil properties under conventional sloping farmland （CSF） and three different reforestation types including a Pinus massoniana secondary forest （PSF）, an Eucommia ulmoides artificial economic forest （EEF） and a natural succession type forest （NST）, were investigated at runoff plot scale over a six-year period in a red soil region of southern China. One hundred and thirty erosive rainfall events generating runoff in plots were grouped into four rainfall types by means of K-mean clustering method. Erosive rainfall type I is the dominant rainfall type. The amount of runoff and the soil loss under erosive rainfall type III were the most, followed by rain-fall type II, IV and I. Compared with CSF treatment, reforestation treatments decreased the average annual runoff depth and the soil loss by 25.5%–61.8% and 93.9%– 96.2% during the study period respectively. Meanwhile, runoff depth at PSF and EEF treatments was significantly lower than that in NST treatment, but no significant difference existed in soil erosion modulus among the three reforestation treatments. This is mainly due to the improved vegetation properties （i.e., vegetation coverage, biomass of above- and below-ground and litter-fall mass） and soil properties （i.e., bulk density, total porosity, infiltration rate and organic carbon content） in the three reforestation treatments compared to CSF treatment. The PSF and EEF are recommended as the preferred reforestation types to control runoff and soil erosion in the red soil region of southern China, with the NST potentially being used as an important supplement.展开更多
Ever since the disastrous floods of 1998, the Chinese government has used the Natural Forest Protection and Sloping Land Conversion Programs to promote afforestation and reforestation as means to reduce runoff, contro...Ever since the disastrous floods of 1998, the Chinese government has used the Natural Forest Protection and Sloping Land Conversion Programs to promote afforestation and reforestation as means to reduce runoff, control erosion, and stabilize local livelihoods. These two ambitious programs have been reported as large-scale successes, contributing to an overall increase in China’s forest cover and to the stated goals of environmental stabilization. A small-scale field study at the project level of the implementation of these two programs in Baiwu Township, Yanyuan County, Sichuan, casts doubt upon the accuracy and reliability of these claims of success; ground observations revealed utter failure in some sites and only marginal success in others. Reasons for this discrepancy are posited as involving ecological, economic, and bureaucratic factors. Further research is suggested to determine whether these discrepancies are merely local aberrations or represent larger-scale failures in reforestation programs.展开更多
Three types of soils： an eroded barren soil under continuous fallow, an eroded soil transplanted with Lespedeza shrubs （Lespedeza bieolor）, and an eroded soil transplanted with camphor tree （Cinnaraomum camphora）...Three types of soils： an eroded barren soil under continuous fallow, an eroded soil transplanted with Lespedeza shrubs （Lespedeza bieolor）, and an eroded soil transplanted with camphor tree （Cinnaraomum camphora） were investigated to quantify organic matter pools and aggregates in reforested soils using physical fractionation techniques and to determine aggregate stability in relation to the enrichment of soil organic carbon （SOC）. Soil organic matter （SOM） was physically fractionalized into free particulate organic matter （fPOM）, occluded particulate organic matter （oPOM）, and mineralassociated organic matter （mOM）. The SOM was concentrated on the surface soil （0 5 cm）, with an average C sequestration rate of 20-25 g C m^-2 year^-1 over 14 years. As compared to the eroded barren land, organic C content of fPOM, oPOM, and mOM fractions of the soil under Lespedeza and under camphor tree increased 12-15, 45-54, and 3.1-3.5 times, respectively. A linear relationship was found between aggregate stability and organic C （r^2 = 0.45, P 〈 0.01）, oPOM （r^2 = 0.34, P 〈 0.05）, and roOM （r^2 = 0.46, P 〈 0.01） of aggregates. The enrichment of organic C improved aggregate stability of the soil under Lespedeza but not that under camphor tree. However, further research is needed on the physical and biological processes involved in the interaction of soil aggregation and SOC sequestration in ecosystem.展开更多
Farmland reforestation can contribute substantially to ecological restoration.Previous studies have extensively examined the ecological effects of farmland reforestation,but few of them have investigated the spatiotem...Farmland reforestation can contribute substantially to ecological restoration.Previous studies have extensively examined the ecological effects of farmland reforestation,but few of them have investigated the spatiotemporal responses of broad-scale landscape connectivity to reforestation.By using a typical agro-pastoral ecotone in northern China as a case study,we addressed this issue based on an innovative integration of circuit theory approach and counterfactual analysis.The forest connectivity through multiple dispersal pathways was measured using the circuit theory approach,and its spatiotemporal changes after reforestation were evaluated by counterfactual analysis.The results showed that from 2000–2015,the reforested farmland occupied 2095 km^2,and 12.5% was on steeply sloped land.Farmland reforestation caused a greater increase in ecological connectivity by adding new ecological corridors and stepping stones in scattered forest areas rather than in areas with dense forest distributions.The newly added corridors and stepping stones were fragmented,short and narrow and thus deserve powerful protection.Future reforestation to improve landscape connectivity should highlight pinch point protection and obstacle removal as well as the tradeoff between farmland loss and farmer survival.Our findings are expected to inform the optimization of the Grain for Green policy from the perspective of broad-scale biodiversity conservation.展开更多
A simplified water balance model in conjunc- tion with an evapotranspiration （ET） model and cumulative forest cover data were used to quantify the changes in annual water yield in response to reforestation in a larg...A simplified water balance model in conjunc- tion with an evapotranspiration （ET） model and cumulative forest cover data were used to quantify the changes in annual water yield in response to reforestation in a large watershed, northeast China. Cumulative forest cover increased by 22 %, leading to a significant decrease in estimated annual water yield. Reforestation increased ET （P = 0.0144）, resulting in a remarkable decrease （P = 0.0001） in estimated annual water yield according to the water balance model. Reforestation increased ET by 33 mm and decreased annual water yield by 38 mm per decade. The effect of reforestation on annual water yield can be quantified using a simplified water balance model in a large watershed, although our reforestation area was small （about 20 %） in relation to the total watershed area.展开更多
The mitigation potential of reforestation for offsetting the deleterious effects of increased flooding and soil erosion projected to occur in Atlantic Canada through future climate change was investigated. Modelling d...The mitigation potential of reforestation for offsetting the deleterious effects of increased flooding and soil erosion projected to occur in Atlantic Canada through future climate change was investigated. Modelling determined a strong but non-linear relationship between extent of vegetative cover and runoff volume and discharge rate for a Nova Scotian watershed, suggesting that reforestation will reduce, but not completely prevent, flooding. Predicted erosion rates were found to be progressively reduced in relation to the extent of upland reforestation. Of three scenarios examined in which 60%, 65%, and 85% of the entire watershed are randomly reforested, only the latter would reduce the elevated erosion expected to occur through climate change back to present-day existing levels. Additional modelling revealed that comparable mitigation of soil erosion can ensue through implementation of 70 m streamside buffer strips, which would only take up 19% of the total surface area. Prioritizing riparian zones for reforestation will therefore subsume less of the overall productive land area and therefore enact a less severe socio-economic impact on agriculture and forestry.展开更多
The impacts of the reforestation of the Sahel-Sahara interface on the seasonal distribution of the surface temperature and thermal extremes are studied in the Sahel (West African region lying between 11°N and ...The impacts of the reforestation of the Sahel-Sahara interface on the seasonal distribution of the surface temperature and thermal extremes are studied in the Sahel (West African region lying between 11°N and 18°N). We performed a simulation with the standard version of the RegCM4 model followed by another one using the altered version of the same model taking into account an incorporated forest. The impacts of the vegetation change are assessed by analyzing the difference between the two runs. The reforestation may influence strongly the frequency of warm days (TG90P) and very warm days (TX90P) by decreasing it over the reforested zone from March to May (MAM) and the entire Sahel during the June-August (JJA) period. These TG90P and TX90P indices decrease may be due to the strengthening of the atmospheric moisture content over the whole Sahel region and the weakening of the sensible heat flux over the reforested zone. The analysis also shows a decrease of the TN90P indice (warm nights) over the Sahel during the wet season (JJA) which could be partly associated with the strengthening of the evapotranspiration over the whole Sahel domain. The analysis of additional thermal indices shows an increase of the tropical nights over the entire Sahel from December to February (DJF) and during the warm season (MAM). The strengthening of the tropical night is partly associated with an increase of the surface net downward shortwave flux over the reforested zone. When considering the heat waves, an increase (a decrease) of these events is recorded over the southern Sahel during JJA and SON periods (over the whole Sahelian region during DJF), respectively. Changes in latent heat flux appear to be largely responsible for these extreme temperatures change. This work shows that the vegetation change may impact positively some regions like the reforested area by reducing the occurrence of thermal extremes;while other Sahel regions (eastern part of the central Sahel) could suffer from it because of the strengthening of thermal extremes.展开更多
Analysis of nature environmental condition and evalwtion of selection and integration ofteclmiques have been carried out in Daxing’an mountains from 1987. The character of soil generaion in this area is influenced by...Analysis of nature environmental condition and evalwtion of selection and integration ofteclmiques have been carried out in Daxing’an mountains from 1987. The character of soil generaion in this area is influenced by the frigid, coniferous forest vegetation, weather, glacier and late soil formation process. Syntliesis teclmiques for high yield plantation include high seedling quality,suitable site preparation and eftbctive protectioll measures for yoimg trees.展开更多
Reforestation is an activity that involves planting or man-made trees regeneration and other plants in the state forest areas and in other areas based on land-use plan designated as forest. The purpose of this study w...Reforestation is an activity that involves planting or man-made trees regeneration and other plants in the state forest areas and in other areas based on land-use plan designated as forest. The purpose of this study was to determine the public perception of the difficulty of successful reforestation activities in the Lake Toba catchment area. The data were taken from primary and secondary data. Primary data were information collected by reforestation activities in the villages, secondary data were collected in the study site general conditions existing at the village government agencies, of which sampling method was done by purposive sampling, i.e., sampling deliberately chosen. The results showed a lack of socialization in the extension of government reforestation activities, uncontrolled forest fires, lack of maintenance of seed that has been planted, and the type of plant is less suitable.展开更多
Relatively simple forest planting process in real life is not so simple. Its relationships with various environmental, climatic, ecological and other environmental conditions cause a lot of problems. In this paper, ha...Relatively simple forest planting process in real life is not so simple. Its relationships with various environmental, climatic, ecological and other environmental conditions cause a lot of problems. In this paper, hazard analysis critical control point （HACCP） analysis was conducted to identify the critical control points in forest regeneration process. As a result, it has a positive effect on the entire reforestation result. Critical control points will enable timely to draw attention to possible errors or incorrect solutions and consequently improve afforestation or restoration quality. Reforestation often occurs mistakes that lead to an unsuccessful reforestation. To remedy this situation, these critical control points should be identified with HAACP analysis.展开更多
After the Second World War of the past century in Italy extended plantations were carried out. In Southern Italy the Calabrian pine （Pinus laricio Poiret） has been the most used species, for its ability to take root...After the Second World War of the past century in Italy extended plantations were carried out. In Southern Italy the Calabrian pine （Pinus laricio Poiret） has been the most used species, for its ability to take root in many difficult conditions. Currently the extension of this vegetation is about 36,000 hectares, in great part established in Calabria. They have reduced hydrogeological risks, they have carried out an important social role and have improved the landscape and the environment of huge hill and mountain territories. After the realization of these stands, no forest management has been made in order to define purposes and silvicultural operations. All stands are currently vulnerable in order to abiotic （fire, breakages） and biotic （Traumatocampa （--- Thaumetopoea） pityocampa （Denis ＆ Schiff.） and Heterobasidion annosum （Fr.） Bref.） agents. For the future, the silvicultural management of these stands will not be able to avoid planning choices, in order to improve the structural stability and the bioecological functionality and to consider the recent opportunities offered from the agroenergetic field.展开更多
The objective of this study was to analyze the profitability of production Parica reforestation in the municipality of Paragominas-PA. The study was conducted in the municipality of Paragominas Messoregiao located in ...The objective of this study was to analyze the profitability of production Parica reforestation in the municipality of Paragominas-PA. The study was conducted in the municipality of Paragominas Messoregiao located in the northeast of Para. The basic data used in the economic evaluation of production of planting parica （costs and revenues） were derived from primary source through raising production cost of parica with farmers from the municipality, analyzing the period of production horizon of seven years. The discount rate chosen for economic evaluation was 10% per year. NPV （net present value） calculation IRR （internal rate of return）, BCR （benefit-cost ratio） and EP （break-even point）. To check the economic feasibility of producing parica the following criteria were used for economic analysis. The results for NPV, IRR and BC ratio were respectively of $495,970, 28.83% and 2.43. For EP （break-even point） the value of 41.08% was found, which demonstrates the minimum amount of production, so that revenue equals costs. Based on the results obtained, it was found that the reforestation model with parica proposed in this paper presents economically viable for deployment.展开更多
Selected fertilizer formulations were assessed for their capacity to enhance growth and nutrition of Jeffrey pine (Pinus jeffreyi Grev. & Balf.) seedlings on an acidic and possibly toxic Sierran surface mine when ...Selected fertilizer formulations were assessed for their capacity to enhance growth and nutrition of Jeffrey pine (Pinus jeffreyi Grev. & Balf.) seedlings on an acidic and possibly toxic Sierran surface mine when applied three years after planting. In a study encompassing five growing seasons conducted on a semiarid, montane surface mine site on the eastern slope of the Sierra Nevada, seedling survival, dimensions, and volume measurements were coupled with foliar and soil analyses for macronutrients, micronutrients, and potentially phytotoxic metallic elements. Administered by broadcasting at four rates each, the formulations consisted of an organic amendment derived from municipal biosolids;a controlled release fertilizer containing urea, ammoniacal, and nitrate N sources;and two conventional fertilizers with one featuring urea as the predominant N form while the other delivered ammoniacal and nitrate forms. None of the formulations induced seedling mortality regardless of application rate, but the controlled release fertilizer and the conventional urea-based formulation were the most stimulatory overall, with intermediate rates of both proving most advantageous among those tested. Foliar analysis revealed that enhanced N and P nutrition, which was otherwise severely impacted by soil infertility, possibly along with that of K, probably accounted for most of the growth stimulation by the amendments, but an accessory role may have been attributable to reduced concentrations of potentially phytotoxic metallic elements, principally Mn but possibly including Fe, Cu, and Al, for which soil levels were all exceedingly elevated. With careful selection of formulation and application rate, post-planting broadcast fertilization can enhance growth and nutrition of Jeffrey pine on degraded substrates. These results provide a more complete understanding of the benefits that judicious fertilization can impart to young forest stands on surface mines and other harsh sites.展开更多
To understand the impacts of reforestation on woody species composition,species diversity and community structure,seven plantation forests in dryhot valley of the Jinsha River in Southwest China were investigated,with...To understand the impacts of reforestation on woody species composition,species diversity and community structure,seven plantation forests in dryhot valley of the Jinsha River in Southwest China were investigated,with adjacent wastelands,natural shrub grassland and a natural forest as references.Species importance value,species richness,species heterogeneity and Sorenson similarity index between plantations and the natural forest were analyzed.Results indicated that compared to wastelands and natural shrub grassland,reforestation improved species diversity and community structure,and more forest woody species found suitable habitats in plantations.Species diversity in understory of plantations and Sorenson similarity index were significantly negatively correlated with stem density in mature plantations(26-31 years old).Higher species diversity and Sorenson similarity index existed in mature sparse plantations due to lower stem density and more tree species planted initially.In contrast,reference natural forest,with species heterogeneity of 2.28 for shrub layer,showed the highest species diversity.It would take a long time for species composition and diversity to recover through reforestation in a dry-hot valley.Therefore,it was essential to protect remnant natural forests strictly and reforest with suitable management such as lower stem density and increasing genetic diversity of trees planted.展开更多
This study explores the status of reforestation programs in Nakasongola Dis-trict,the role of community participation in their implementation,and the challenges hindering effective engagement.Utilizing a descriptive r...This study explores the status of reforestation programs in Nakasongola Dis-trict,the role of community participation in their implementation,and the challenges hindering effective engagement.Utilizing a descriptive research de-sign with quantitative and qualitative approaches,data were collected from 328 respondents through structured questionnaires and semi-structured inter-views.The data were analyzed using Excel for data cleaning and SPSS for ad-vanced statistical analysis,including chi-square tests to identify significant as-sociations.The findings reveal that reforestation efforts in Nakasongola are driven by mechanisms such as the provision of seedlings by government and non-governmental organizations,periodic tree planting,land allocation,and the establishment of tree schemes.Community participation plays a pivotal role in planning,planting,and monitoring activities,with a significant associa-tion observed between community involvement and program effectiveness.However,challenges such as financial constraints,limited information,low com-munity awareness,and restricted access to reforestation schemes undermine the sustainability of these programs.This study highlights the need for a robust pol-icy framework to strengthen institutional capacity,enhance resource allocation,and empower communities through inclusive,data-driven strategies.The find-ings provide a replicable model for evaluating and improving reforestation ef-forts in other regions facing similar environmental challenges,promoting sus-tainable forest management and community-led conservation initiatives.展开更多
Aims Boreal larch(Larix gmelinii)forests in Northeast China have been widely disturbed since the 1987 conflagration;however,its long-term effects on the forest carbon(C)cycling have not been explored.The objective of ...Aims Boreal larch(Larix gmelinii)forests in Northeast China have been widely disturbed since the 1987 conflagration;however,its long-term effects on the forest carbon(C)cycling have not been explored.The objective of this study thus was to quantify the effects of fire severity and post-fire reforestation on C pools and the changes of these forests.Methods Sixteen permanent plots have been set in two types of larch stands(L.gmelinii-grass,LG;and L.gmelinii-Rhododendron dahurica,LR)with three levels of fire severity(unburned,low-severity and high-severity but replanted),at 1987 burned sites in Daxing’anling,northeastern China,to repeatedly measure ecosystem C pools in 1998 and 2014.C components were partitioned into vegetation(foliage,branch,stem and roots),soil and detritus(standing and fallen woody debris and litter).The fire effects on post-fire C dynamics were examined by comparing the differences of C pools and changes between the two field investigations caused by fire severity.Important Findings During the study period,unburned mature stands were C sinks(105 g C m^(−2) year^(−1) for LG,and 190 g C m^(−2) year^(−1) for LR),whereas the low-severity stands were C-neutral(−4 and 15 g C m^(−2) year^(−1) for LG and LR,respectively).The high-severity burned but reforested stands were C sinks,among which,however,magnitudes(88 and 16 g C m^(−2) year^(−1) for LG and LR,respectively)were smaller than those of the two unburned stands.Detritus C pools decreased significantly(with a loss ranging from 26 to 38 g C m^(−2) year^(−1))in the burned stands during recent restoration.Soil organic C pools increased slightly in the unmanaged stands(unburned and lowseverity,with accumulation rates ranging from 4 to 35 g C m^(−2) year^(−1)),but decreased for the high-severity replanted stands(loss rates of 28 and 36 g C m^(−2) year^(−1) for LG and LR,respectively).These results indicate that fire severity has a dynamic post-fire effect on both C pools and distributions of the boreal larch forests,and that effective reforestation practice accelerates forest C sequestration.展开更多
Forests are an important natural resource,vital to all life.Forests are an important source of food,clothing,and medicines,as well as a place to live.Water released from forests drains into the soil causing groundwate...Forests are an important natural resource,vital to all life.Forests are an important source of food,clothing,and medicines,as well as a place to live.Water released from forests drains into the soil causing groundwater to emerge as stream flow throughout the year.In Thailand,most forests have been encroached by logging,paper production,and housing construction.Population growth and the need for farming area for crop and livestock production have also caused forest encroachment.Technical tools are needed to support the decision makers and planners if they are to achieve objectives of water conservation,and development.These technical tools are needed for assistance in the engineering,socio-economic,and environmental planning.The Soil and Water Assessment Tool(SWAT)was used in the hydrological modeling in this study of the complex and dynamic problems of The Upper Nan river basin.This was a case study to evaluate the impact of changing conditions in the river basin affected by the stream flow due to reforestation.The watershed area was delineated into 5 sub-watersheds based on surface topography provided by the Digital Elevation Model(DEM)and the parameters of each of these watersheds were calculated.The land use data was processed and reclassified to match with the SWAT model land use code.Ten different categories of land use in the study area were used for SWAT processing.Types of land use consist of:mixed forest(33.7%),disturbed forest(30.2%),evergreen forest(17.7%),paddy field(7.1%),orchard(3.7%),range brush(2.7%),field crop(1.7%),planted forest(1.7%),urban(1.4%)and water resources(0.4%).Twenty-two types of soil were found in the basin.The initial curve number values were assigned based on the land use type and soil hydrologic group for the average antecedent moisture condition of the curve number method.The potential evapotranspiration was computed using the Penman-Monteith method.The simulation was performed using three reforestation scenarios to assess stream flow:(1)improved disturbed forest,(2)field crops and range grass,and(3)both disturbed forest and field crops.The results of reforestation from scenarios 1 and 3 can increase stream flow in the drought season and can also reduce the flow in the wet season in the main stream and its tributaries.For scenario 2 Reforestation had no significant effect on the main stream.展开更多
Aims Reforestation can enhance soil carbon(C)stability and promote soil C accumulation.Experimental results are,however,highly variable,and the efficacy of reforestation in enhancing soil C stability is still in debat...Aims Reforestation can enhance soil carbon(C)stability and promote soil C accumulation.Experimental results are,however,highly variable,and the efficacy of reforestation in enhancing soil C stability is still in debate.Consequently,it remains unclear how the different soil C pools respond to reforestation in forest ecosystems.Methods The response of different soil C fractions to reforestation was examined in five subtropical forests,including the plantations of Eucalyptus urophylla(EU),Acacia crassicarpa(AC),Castanopsis hystrix(CH)and 10 species mixed(MX),and a naturally recovered shrubland(NS).Soil labile C fractions(readily oxidized organic C by KMnO4:ROC;dissolved organic C:DOC),distribution of aggregate-size classes and aggregate-associated C from different soil layers(0–10,10–20,20–40 and 40–60 cm)were evaluated.Important Findings We found that reforestation and forest type did not affect ROC concentration,yet the highest DOC concentration was detected in NS at four soil layers.Aggregate C concentration was the highest in all aggregate-size classes of CH at 0–10 cm depth.In addition,forest type did not alter the proportion of soil water-stable aggregates at four soil layers.However,soil depths significantly affected the distribution of soil aggregates with>0.25 mm aggregates dominating in the topsoils(0–20 cm),but 0.053–2 mm aggregates being dominant in the deep soils(20–60 cm).These results indicate that reforestation and forest type affected soil DOC(0–60 cm)and aggregate C(0–10 cm).Furthermore,soil DOC and aggregate C were more susceptive to reforestation than ROC.The findings suggest that plantations reduce soil DOC concentration,highlighting that C leaching loss may decrease compared with natural recovery.Moreover,C.hystrix plantation may enhance soil C stability by physical protection in topsoil.This study provides valuable information on tree species selection for reforestation concerning soil C sequestration in southern subtropical China.展开更多
Uncovering the mechanisms underlying the diversity patterns of abundant and rare species is crucial for terrestrial biodiversity maintenance.However,the response of abundant and rare community assembly to ecological s...Uncovering the mechanisms underlying the diversity patterns of abundant and rare species is crucial for terrestrial biodiversity maintenance.However,the response of abundant and rare community assembly to ecological succession has not been explored,particularly considering soil profiles.Here 300 soil samples were collected from reforestation ecosystems from depths of up to 300 cm and horizontal distances of 30–90 cm from a tree.We revealed that soil phosphorus not only affected alpha diversity and community structure,but also mediated the balance of stochastic and deterministic processes for abundant and rare sub-communities,which exhibited contrasting assembly strategies.The abundant sub-community changed from variable selection to stochasticity with the increase of phosphorus,while the rare sub-community shifted from homogeneous selection to stochasticity.Dispersal limitation was the main assembly process in the abundant sub-community,while the rare sub-community was governed primarily by homogeneous selection.Moreover,the relative influence of deterministic processes increased with succession for both sub-communities.At the scale of a single tree,stochastic processes increased with soil depth in rare sub-community,while deterministic processes increased with the radius from a single tree in the abundant subcommunity.Overall,our results highlight the importance of the soil phosphorus-driven assembly process in understanding the re-assembly and maintenance of soil bacterial diversity.展开更多
基金supported by the National Natural Science Foundation of China(NO.32201626)the Key Research and Development Program of Jiangxi Province(20223BBG74S01,20223BBG71013).
文摘In response to the effectiveness of reforestation in controlling soil erosion,there has been a dramatic increase in forest coverage in the hilly red soil region of southern China.Aggregate stability and soil shear strength are indicators that reflect soil resistance to erosion and its ability to prevent shallow landslides,respectively.However,limited research has focused on the response of soil aggregate stability and shear strength to reforestation.We selected three types of reforestations(Phyllostachys edulis forest,Cunninghamia lanceolata(Lamb.)Hook.forest,Citrus sinensis(L.)Osbeck.orchard),a natural forest(mixed coniferous and broadleaf forests),and a fallow land as study plots,and measured root traits,and soil physicochemical traits,i.e.,pH,soil organic matter(SOC),Soil water content(SWC),soil bulk density(BD),soil cohesion(c),soil internal friction angle(φ)and analyzed their multiple interactions.The soil aggregate stability traits,refer to the mean weight diameter(MWD)and geometric mean diameter(GMD),exhibited a significant increase in reforested plots,approximately 200%compared to fallow land and 50%compared to natural forests.For soil shear strength the values were approximately 20%higher than in fallow land and approximately 10%lower than in natural forests.Soil aggregate stability and soil shear strength did not exhibit a significant positive correlation across all plots,and the underlying drivers of these traits were variable.For instance,in natural forest and timber stands,soil aggregate stability was mainly influenced by soil organic carbon,while soil shear strength was primarily affected by root length density.In economic forest,aggregate stability and shear strength are mainly affected by organic carbon.Overall,we found that vegetation restoration enhances soil erosion resistance,however,the primary drivers for the improvement of aggregate stability(soil organic carbon)and shear strength(root length density)are different.Therefore,in future benefit assessments of vegetation restoration projects aimed at soil erosion control,different indicators should be considered based on specific conditions.
基金supported by the National Natural Science Foundation of China(No.30428028)the Innovation Group Project of the National Natural Science Foundation of China(No.40621061)
文摘To evaluate the long-term effects of reforestation types on soil erosion on degraded land, vegetation and soil properties under conventional sloping farmland （CSF） and three different reforestation types including a Pinus massoniana secondary forest （PSF）, an Eucommia ulmoides artificial economic forest （EEF） and a natural succession type forest （NST）, were investigated at runoff plot scale over a six-year period in a red soil region of southern China. One hundred and thirty erosive rainfall events generating runoff in plots were grouped into four rainfall types by means of K-mean clustering method. Erosive rainfall type I is the dominant rainfall type. The amount of runoff and the soil loss under erosive rainfall type III were the most, followed by rain-fall type II, IV and I. Compared with CSF treatment, reforestation treatments decreased the average annual runoff depth and the soil loss by 25.5%–61.8% and 93.9%– 96.2% during the study period respectively. Meanwhile, runoff depth at PSF and EEF treatments was significantly lower than that in NST treatment, but no significant difference existed in soil erosion modulus among the three reforestation treatments. This is mainly due to the improved vegetation properties （i.e., vegetation coverage, biomass of above- and below-ground and litter-fall mass） and soil properties （i.e., bulk density, total porosity, infiltration rate and organic carbon content） in the three reforestation treatments compared to CSF treatment. The PSF and EEF are recommended as the preferred reforestation types to control runoff and soil erosion in the red soil region of southern China, with the NST potentially being used as an important supplement.
文摘Ever since the disastrous floods of 1998, the Chinese government has used the Natural Forest Protection and Sloping Land Conversion Programs to promote afforestation and reforestation as means to reduce runoff, control erosion, and stabilize local livelihoods. These two ambitious programs have been reported as large-scale successes, contributing to an overall increase in China’s forest cover and to the stated goals of environmental stabilization. A small-scale field study at the project level of the implementation of these two programs in Baiwu Township, Yanyuan County, Sichuan, casts doubt upon the accuracy and reliability of these claims of success; ground observations revealed utter failure in some sites and only marginal success in others. Reasons for this discrepancy are posited as involving ecological, economic, and bureaucratic factors. Further research is suggested to determine whether these discrepancies are merely local aberrations or represent larger-scale failures in reforestation programs.
基金Project supported by the National Natural Science Foundation of China (No. 40071055)
文摘Three types of soils： an eroded barren soil under continuous fallow, an eroded soil transplanted with Lespedeza shrubs （Lespedeza bieolor）, and an eroded soil transplanted with camphor tree （Cinnaraomum camphora） were investigated to quantify organic matter pools and aggregates in reforested soils using physical fractionation techniques and to determine aggregate stability in relation to the enrichment of soil organic carbon （SOC）. Soil organic matter （SOM） was physically fractionalized into free particulate organic matter （fPOM）, occluded particulate organic matter （oPOM）, and mineralassociated organic matter （mOM）. The SOM was concentrated on the surface soil （0 5 cm）, with an average C sequestration rate of 20-25 g C m^-2 year^-1 over 14 years. As compared to the eroded barren land, organic C content of fPOM, oPOM, and mOM fractions of the soil under Lespedeza and under camphor tree increased 12-15, 45-54, and 3.1-3.5 times, respectively. A linear relationship was found between aggregate stability and organic C （r^2 = 0.45, P 〈 0.01）, oPOM （r^2 = 0.34, P 〈 0.05）, and roOM （r^2 = 0.46, P 〈 0.01） of aggregates. The enrichment of organic C improved aggregate stability of the soil under Lespedeza but not that under camphor tree. However, further research is needed on the physical and biological processes involved in the interaction of soil aggregation and SOC sequestration in ecosystem.
基金National Natural Science Foundation of China,No.41771429National Key Research and Development Project,No.2017YFB0503505。
文摘Farmland reforestation can contribute substantially to ecological restoration.Previous studies have extensively examined the ecological effects of farmland reforestation,but few of them have investigated the spatiotemporal responses of broad-scale landscape connectivity to reforestation.By using a typical agro-pastoral ecotone in northern China as a case study,we addressed this issue based on an innovative integration of circuit theory approach and counterfactual analysis.The forest connectivity through multiple dispersal pathways was measured using the circuit theory approach,and its spatiotemporal changes after reforestation were evaluated by counterfactual analysis.The results showed that from 2000–2015,the reforested farmland occupied 2095 km^2,and 12.5% was on steeply sloped land.Farmland reforestation caused a greater increase in ecological connectivity by adding new ecological corridors and stepping stones in scattered forest areas rather than in areas with dense forest distributions.The newly added corridors and stepping stones were fragmented,short and narrow and thus deserve powerful protection.Future reforestation to improve landscape connectivity should highlight pinch point protection and obstacle removal as well as the tradeoff between farmland loss and farmer survival.Our findings are expected to inform the optimization of the Grain for Green policy from the perspective of broad-scale biodiversity conservation.
基金financially supported by the State Forestry Administration of China(201404201)the Guangxi Natural Science Foundation of China(2012GXNSFBA053140)+2 种基金the Fundamental Research Funds of Guangxi Academy of Sciences(13YJ22ZWS22)the Guangxi Institute of Botany(12001)CFERN&GENE Award Funds on Ecological Paper
文摘A simplified water balance model in conjunc- tion with an evapotranspiration （ET） model and cumulative forest cover data were used to quantify the changes in annual water yield in response to reforestation in a large watershed, northeast China. Cumulative forest cover increased by 22 %, leading to a significant decrease in estimated annual water yield. Reforestation increased ET （P = 0.0144）, resulting in a remarkable decrease （P = 0.0001） in estimated annual water yield according to the water balance model. Reforestation increased ET by 33 mm and decreased annual water yield by 38 mm per decade. The effect of reforestation on annual water yield can be quantified using a simplified water balance model in a large watershed, although our reforestation area was small （about 20 %） in relation to the total watershed area.
文摘The mitigation potential of reforestation for offsetting the deleterious effects of increased flooding and soil erosion projected to occur in Atlantic Canada through future climate change was investigated. Modelling determined a strong but non-linear relationship between extent of vegetative cover and runoff volume and discharge rate for a Nova Scotian watershed, suggesting that reforestation will reduce, but not completely prevent, flooding. Predicted erosion rates were found to be progressively reduced in relation to the extent of upland reforestation. Of three scenarios examined in which 60%, 65%, and 85% of the entire watershed are randomly reforested, only the latter would reduce the elevated erosion expected to occur through climate change back to present-day existing levels. Additional modelling revealed that comparable mitigation of soil erosion can ensue through implementation of 70 m streamside buffer strips, which would only take up 19% of the total surface area. Prioritizing riparian zones for reforestation will therefore subsume less of the overall productive land area and therefore enact a less severe socio-economic impact on agriculture and forestry.
文摘The impacts of the reforestation of the Sahel-Sahara interface on the seasonal distribution of the surface temperature and thermal extremes are studied in the Sahel (West African region lying between 11°N and 18°N). We performed a simulation with the standard version of the RegCM4 model followed by another one using the altered version of the same model taking into account an incorporated forest. The impacts of the vegetation change are assessed by analyzing the difference between the two runs. The reforestation may influence strongly the frequency of warm days (TG90P) and very warm days (TX90P) by decreasing it over the reforested zone from March to May (MAM) and the entire Sahel during the June-August (JJA) period. These TG90P and TX90P indices decrease may be due to the strengthening of the atmospheric moisture content over the whole Sahel region and the weakening of the sensible heat flux over the reforested zone. The analysis also shows a decrease of the TN90P indice (warm nights) over the Sahel during the wet season (JJA) which could be partly associated with the strengthening of the evapotranspiration over the whole Sahel domain. The analysis of additional thermal indices shows an increase of the tropical nights over the entire Sahel from December to February (DJF) and during the warm season (MAM). The strengthening of the tropical night is partly associated with an increase of the surface net downward shortwave flux over the reforested zone. When considering the heat waves, an increase (a decrease) of these events is recorded over the southern Sahel during JJA and SON periods (over the whole Sahelian region during DJF), respectively. Changes in latent heat flux appear to be largely responsible for these extreme temperatures change. This work shows that the vegetation change may impact positively some regions like the reforested area by reducing the occurrence of thermal extremes;while other Sahel regions (eastern part of the central Sahel) could suffer from it because of the strengthening of thermal extremes.
文摘Analysis of nature environmental condition and evalwtion of selection and integration ofteclmiques have been carried out in Daxing’an mountains from 1987. The character of soil generaion in this area is influenced by the frigid, coniferous forest vegetation, weather, glacier and late soil formation process. Syntliesis teclmiques for high yield plantation include high seedling quality,suitable site preparation and eftbctive protectioll measures for yoimg trees.
文摘Reforestation is an activity that involves planting or man-made trees regeneration and other plants in the state forest areas and in other areas based on land-use plan designated as forest. The purpose of this study was to determine the public perception of the difficulty of successful reforestation activities in the Lake Toba catchment area. The data were taken from primary and secondary data. Primary data were information collected by reforestation activities in the villages, secondary data were collected in the study site general conditions existing at the village government agencies, of which sampling method was done by purposive sampling, i.e., sampling deliberately chosen. The results showed a lack of socialization in the extension of government reforestation activities, uncontrolled forest fires, lack of maintenance of seed that has been planted, and the type of plant is less suitable.
文摘Relatively simple forest planting process in real life is not so simple. Its relationships with various environmental, climatic, ecological and other environmental conditions cause a lot of problems. In this paper, hazard analysis critical control point （HACCP） analysis was conducted to identify the critical control points in forest regeneration process. As a result, it has a positive effect on the entire reforestation result. Critical control points will enable timely to draw attention to possible errors or incorrect solutions and consequently improve afforestation or restoration quality. Reforestation often occurs mistakes that lead to an unsuccessful reforestation. To remedy this situation, these critical control points should be identified with HAACP analysis.
文摘After the Second World War of the past century in Italy extended plantations were carried out. In Southern Italy the Calabrian pine （Pinus laricio Poiret） has been the most used species, for its ability to take root in many difficult conditions. Currently the extension of this vegetation is about 36,000 hectares, in great part established in Calabria. They have reduced hydrogeological risks, they have carried out an important social role and have improved the landscape and the environment of huge hill and mountain territories. After the realization of these stands, no forest management has been made in order to define purposes and silvicultural operations. All stands are currently vulnerable in order to abiotic （fire, breakages） and biotic （Traumatocampa （--- Thaumetopoea） pityocampa （Denis ＆ Schiff.） and Heterobasidion annosum （Fr.） Bref.） agents. For the future, the silvicultural management of these stands will not be able to avoid planning choices, in order to improve the structural stability and the bioecological functionality and to consider the recent opportunities offered from the agroenergetic field.
文摘The objective of this study was to analyze the profitability of production Parica reforestation in the municipality of Paragominas-PA. The study was conducted in the municipality of Paragominas Messoregiao located in the northeast of Para. The basic data used in the economic evaluation of production of planting parica （costs and revenues） were derived from primary source through raising production cost of parica with farmers from the municipality, analyzing the period of production horizon of seven years. The discount rate chosen for economic evaluation was 10% per year. NPV （net present value） calculation IRR （internal rate of return）, BCR （benefit-cost ratio） and EP （break-even point）. To check the economic feasibility of producing parica the following criteria were used for economic analysis. The results for NPV, IRR and BC ratio were respectively of $495,970, 28.83% and 2.43. For EP （break-even point） the value of 41.08% was found, which demonstrates the minimum amount of production, so that revenue equals costs. Based on the results obtained, it was found that the reforestation model with parica proposed in this paper presents economically viable for deployment.
文摘Selected fertilizer formulations were assessed for their capacity to enhance growth and nutrition of Jeffrey pine (Pinus jeffreyi Grev. & Balf.) seedlings on an acidic and possibly toxic Sierran surface mine when applied three years after planting. In a study encompassing five growing seasons conducted on a semiarid, montane surface mine site on the eastern slope of the Sierra Nevada, seedling survival, dimensions, and volume measurements were coupled with foliar and soil analyses for macronutrients, micronutrients, and potentially phytotoxic metallic elements. Administered by broadcasting at four rates each, the formulations consisted of an organic amendment derived from municipal biosolids;a controlled release fertilizer containing urea, ammoniacal, and nitrate N sources;and two conventional fertilizers with one featuring urea as the predominant N form while the other delivered ammoniacal and nitrate forms. None of the formulations induced seedling mortality regardless of application rate, but the controlled release fertilizer and the conventional urea-based formulation were the most stimulatory overall, with intermediate rates of both proving most advantageous among those tested. Foliar analysis revealed that enhanced N and P nutrition, which was otherwise severely impacted by soil infertility, possibly along with that of K, probably accounted for most of the growth stimulation by the amendments, but an accessory role may have been attributable to reduced concentrations of potentially phytotoxic metallic elements, principally Mn but possibly including Fe, Cu, and Al, for which soil levels were all exceedingly elevated. With careful selection of formulation and application rate, post-planting broadcast fertilization can enhance growth and nutrition of Jeffrey pine on degraded substrates. These results provide a more complete understanding of the benefits that judicious fertilization can impart to young forest stands on surface mines and other harsh sites.
基金supported financially by the Program of Introducing Talents of Discipline to Universities (B08037)
文摘To understand the impacts of reforestation on woody species composition,species diversity and community structure,seven plantation forests in dryhot valley of the Jinsha River in Southwest China were investigated,with adjacent wastelands,natural shrub grassland and a natural forest as references.Species importance value,species richness,species heterogeneity and Sorenson similarity index between plantations and the natural forest were analyzed.Results indicated that compared to wastelands and natural shrub grassland,reforestation improved species diversity and community structure,and more forest woody species found suitable habitats in plantations.Species diversity in understory of plantations and Sorenson similarity index were significantly negatively correlated with stem density in mature plantations(26-31 years old).Higher species diversity and Sorenson similarity index existed in mature sparse plantations due to lower stem density and more tree species planted initially.In contrast,reference natural forest,with species heterogeneity of 2.28 for shrub layer,showed the highest species diversity.It would take a long time for species composition and diversity to recover through reforestation in a dry-hot valley.Therefore,it was essential to protect remnant natural forests strictly and reforest with suitable management such as lower stem density and increasing genetic diversity of trees planted.
文摘This study explores the status of reforestation programs in Nakasongola Dis-trict,the role of community participation in their implementation,and the challenges hindering effective engagement.Utilizing a descriptive research de-sign with quantitative and qualitative approaches,data were collected from 328 respondents through structured questionnaires and semi-structured inter-views.The data were analyzed using Excel for data cleaning and SPSS for ad-vanced statistical analysis,including chi-square tests to identify significant as-sociations.The findings reveal that reforestation efforts in Nakasongola are driven by mechanisms such as the provision of seedlings by government and non-governmental organizations,periodic tree planting,land allocation,and the establishment of tree schemes.Community participation plays a pivotal role in planning,planting,and monitoring activities,with a significant associa-tion observed between community involvement and program effectiveness.However,challenges such as financial constraints,limited information,low com-munity awareness,and restricted access to reforestation schemes undermine the sustainability of these programs.This study highlights the need for a robust pol-icy framework to strengthen institutional capacity,enhance resource allocation,and empower communities through inclusive,data-driven strategies.The find-ings provide a replicable model for evaluating and improving reforestation ef-forts in other regions facing similar environmental challenges,promoting sus-tainable forest management and community-led conservation initiatives.
基金National Natural Science Foundation of China(31321061,31330012)National Basic Research Program of China on Global Change(2014CB954001)+2 种基金National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2011BAD37B01)Chinese Academy of Sciences(XDA05050000)Program for Changjiang Scholars and Innovative Research Team in University(IRT1054).
文摘Aims Boreal larch(Larix gmelinii)forests in Northeast China have been widely disturbed since the 1987 conflagration;however,its long-term effects on the forest carbon(C)cycling have not been explored.The objective of this study thus was to quantify the effects of fire severity and post-fire reforestation on C pools and the changes of these forests.Methods Sixteen permanent plots have been set in two types of larch stands(L.gmelinii-grass,LG;and L.gmelinii-Rhododendron dahurica,LR)with three levels of fire severity(unburned,low-severity and high-severity but replanted),at 1987 burned sites in Daxing’anling,northeastern China,to repeatedly measure ecosystem C pools in 1998 and 2014.C components were partitioned into vegetation(foliage,branch,stem and roots),soil and detritus(standing and fallen woody debris and litter).The fire effects on post-fire C dynamics were examined by comparing the differences of C pools and changes between the two field investigations caused by fire severity.Important Findings During the study period,unburned mature stands were C sinks(105 g C m^(−2) year^(−1) for LG,and 190 g C m^(−2) year^(−1) for LR),whereas the low-severity stands were C-neutral(−4 and 15 g C m^(−2) year^(−1) for LG and LR,respectively).The high-severity burned but reforested stands were C sinks,among which,however,magnitudes(88 and 16 g C m^(−2) year^(−1) for LG and LR,respectively)were smaller than those of the two unburned stands.Detritus C pools decreased significantly(with a loss ranging from 26 to 38 g C m^(−2) year^(−1))in the burned stands during recent restoration.Soil organic C pools increased slightly in the unmanaged stands(unburned and lowseverity,with accumulation rates ranging from 4 to 35 g C m^(−2) year^(−1)),but decreased for the high-severity replanted stands(loss rates of 28 and 36 g C m^(−2) year^(−1) for LG and LR,respectively).These results indicate that fire severity has a dynamic post-fire effect on both C pools and distributions of the boreal larch forests,and that effective reforestation practice accelerates forest C sequestration.
文摘Forests are an important natural resource,vital to all life.Forests are an important source of food,clothing,and medicines,as well as a place to live.Water released from forests drains into the soil causing groundwater to emerge as stream flow throughout the year.In Thailand,most forests have been encroached by logging,paper production,and housing construction.Population growth and the need for farming area for crop and livestock production have also caused forest encroachment.Technical tools are needed to support the decision makers and planners if they are to achieve objectives of water conservation,and development.These technical tools are needed for assistance in the engineering,socio-economic,and environmental planning.The Soil and Water Assessment Tool(SWAT)was used in the hydrological modeling in this study of the complex and dynamic problems of The Upper Nan river basin.This was a case study to evaluate the impact of changing conditions in the river basin affected by the stream flow due to reforestation.The watershed area was delineated into 5 sub-watersheds based on surface topography provided by the Digital Elevation Model(DEM)and the parameters of each of these watersheds were calculated.The land use data was processed and reclassified to match with the SWAT model land use code.Ten different categories of land use in the study area were used for SWAT processing.Types of land use consist of:mixed forest(33.7%),disturbed forest(30.2%),evergreen forest(17.7%),paddy field(7.1%),orchard(3.7%),range brush(2.7%),field crop(1.7%),planted forest(1.7%),urban(1.4%)and water resources(0.4%).Twenty-two types of soil were found in the basin.The initial curve number values were assigned based on the land use type and soil hydrologic group for the average antecedent moisture condition of the curve number method.The potential evapotranspiration was computed using the Penman-Monteith method.The simulation was performed using three reforestation scenarios to assess stream flow:(1)improved disturbed forest,(2)field crops and range grass,and(3)both disturbed forest and field crops.The results of reforestation from scenarios 1 and 3 can increase stream flow in the drought season and can also reduce the flow in the wet season in the main stream and its tributaries.For scenario 2 Reforestation had no significant effect on the main stream.
基金the National Natural Science Foundation of China(31901194)the Joint Funds of National Natural Science Foundation of China and Henan Province of China(U1904204).
文摘Aims Reforestation can enhance soil carbon(C)stability and promote soil C accumulation.Experimental results are,however,highly variable,and the efficacy of reforestation in enhancing soil C stability is still in debate.Consequently,it remains unclear how the different soil C pools respond to reforestation in forest ecosystems.Methods The response of different soil C fractions to reforestation was examined in five subtropical forests,including the plantations of Eucalyptus urophylla(EU),Acacia crassicarpa(AC),Castanopsis hystrix(CH)and 10 species mixed(MX),and a naturally recovered shrubland(NS).Soil labile C fractions(readily oxidized organic C by KMnO4:ROC;dissolved organic C:DOC),distribution of aggregate-size classes and aggregate-associated C from different soil layers(0–10,10–20,20–40 and 40–60 cm)were evaluated.Important Findings We found that reforestation and forest type did not affect ROC concentration,yet the highest DOC concentration was detected in NS at four soil layers.Aggregate C concentration was the highest in all aggregate-size classes of CH at 0–10 cm depth.In addition,forest type did not alter the proportion of soil water-stable aggregates at four soil layers.However,soil depths significantly affected the distribution of soil aggregates with>0.25 mm aggregates dominating in the topsoils(0–20 cm),but 0.053–2 mm aggregates being dominant in the deep soils(20–60 cm).These results indicate that reforestation and forest type affected soil DOC(0–60 cm)and aggregate C(0–10 cm).Furthermore,soil DOC and aggregate C were more susceptive to reforestation than ROC.The findings suggest that plantations reduce soil DOC concentration,highlighting that C leaching loss may decrease compared with natural recovery.Moreover,C.hystrix plantation may enhance soil C stability by physical protection in topsoil.This study provides valuable information on tree species selection for reforestation concerning soil C sequestration in southern subtropical China.
基金the National Science Foundation of China(Grant Nos.:42077222,41807030 and 41830755)。
文摘Uncovering the mechanisms underlying the diversity patterns of abundant and rare species is crucial for terrestrial biodiversity maintenance.However,the response of abundant and rare community assembly to ecological succession has not been explored,particularly considering soil profiles.Here 300 soil samples were collected from reforestation ecosystems from depths of up to 300 cm and horizontal distances of 30–90 cm from a tree.We revealed that soil phosphorus not only affected alpha diversity and community structure,but also mediated the balance of stochastic and deterministic processes for abundant and rare sub-communities,which exhibited contrasting assembly strategies.The abundant sub-community changed from variable selection to stochasticity with the increase of phosphorus,while the rare sub-community shifted from homogeneous selection to stochasticity.Dispersal limitation was the main assembly process in the abundant sub-community,while the rare sub-community was governed primarily by homogeneous selection.Moreover,the relative influence of deterministic processes increased with succession for both sub-communities.At the scale of a single tree,stochastic processes increased with soil depth in rare sub-community,while deterministic processes increased with the radius from a single tree in the abundant subcommunity.Overall,our results highlight the importance of the soil phosphorus-driven assembly process in understanding the re-assembly and maintenance of soil bacterial diversity.
