Reforestation Programs in Southwest China:Reported Success,Observed Failure, and the Reasons Why

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.

Effect of reforestation on annual water yield in a large watershed in northeast China

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.

De-farming and Ecological Restoration in the Loess Hilly-gully Region in Northern China

De-farming has been a powerful measure taken by the central and local governments of China for ecological restoration in the loess hilly-gully region since 2000. In years past, aid-based de-farming pattern was far and wide popularized in the region and terrace-based de-farming pattern demonstrated in a few small watersheds was also rather effective for ecological restoration. After summing up the features of three patterns (aid-based de-farming slope farmland more than 25°(AD25), aid-based de-farming slope farmland more than 15° (AD15) and terrace-based de-farming (TD)), this paper analyzed the regional difference of these patterns in de-farming area, ecological restoration, investment demand and so on. The results show that there are two crucial areas in the loess hilly-gully region for ecological restoration at the moment, the policies adaptation to the different areas should be constituted as soon as possible and the limited fund should be devoted to the two crucial areas.

Organic Matter Enrichment and Aggregate Stabilization in a Severely Degraded Ultisol After Reforestation

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.

A comparison between different ecological de-farming modes in the loess hilly-gully region in China

The eco-environmental restoration has been a chief task of the western development strategies carried out by the central and local governments of China since the late 1990s, and the ecological de-farming has been regarded as a powerful measure for the ecological restoration in the Loess Plateau and the upper reaches of the Yangtze River. "Relieving and de-farming" (RD) and "rebuilding terrace and de-farming" (RTD) are two more mature ones among various de-farming modes. Taking the loess hilly-gully region as a case, this paper summarized the basic characteristics of RD and RTD modes, calculated the sizes of de-farming slope farmland, rebuilt terraces, enlarged garden plots and restored vegetation, and compared the differences of two modes in terms of de-farming area, ecological reestablishment index, investment demand amount and benefits. The results showed that RTD mode has many advantages, including suitable investment, sufficient grain supply and great benefits, and will be the best ecological reestablishment mode in the loess hilly-gully region, and RD mode which is being carried out in this region should be replaced by RTD mode as soon as possible.

Modeling Reforestation’s Role in Climate-Proofing Watersheds from Flooding and Soil Erosion

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.

Impacts of the Sahel-Sahara Interface Reforestation on West African Climate: Intra-Annual Variability and Extreme Temperature Events

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&#176N and 18&#176N). 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.

THE ENVIRONMENTAL CHARACTERISTICS OF FOREST LAND AND THE TECHNIQUES OF REFORESTATION IN FIRED LAND IN DAXING'AN MOUNTAINS

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.

Planning Method of Eco-environment Restoration Based on Enlarging Terrace and De-farming in Loess Hilly Region——A Case Study of Yangou Catchment

After expatiating the guiding ideology,contents,standards and principles of eco-environment restoration based on enlarging terrace and de-farming,this paper discussed the planning method and technical flow of enlarging terrace and garden plot in a small catchment of loess hilly region by means of GIS spatial analysis technology,and then the planning method was applied in Yangou catchment.The result showed that it is practicabl,and the areas of newly-built terrace and garden plot in Yangou catchment are at least 295.06 and 4.61 hm2,so that the areas of basic farmland and garden plot reach 359.23 and 622.69 hm2.After the land use structure is regulated,the forest coverage is 48.87%,and the permanent vegetation coverage is about 75% in Yangou catchment,while sediment reduction benefit is above 80% in slope land.In agricultural development,Yangou catchment can yield 1 645.13 tons of food supplies,above 9 340 tons of apples,and can feed 7 500 sheep every year.

Post-Planting Fertilization as a Reforestation Aid on a Sulfurous, Semiarid Surface Mine

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.

Management Guidelines for Calabrian Pine Reforestations Carried Out in Southern Italy in the 1950s-70s

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.

Public Perception on the Success of Reforestation in a Degraded Land

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.

Economic Viability of Production of Tree Parica （Schizolobium amazonicum Huber ex. Ducke） of Reforestation Project in the Municipality Paragominas-PA, Brazil

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.

Succession and Enhancement Mechanism of Ecosystem Productivity in the De-farming Area of the Ecotone Between Agriculture and Animal Husbandry in North China

The succession and enhancement mechanism of the ecosystem productivity with the characteristics ot de-tarmlng in me ecotone between agriculture and animal husbandry in North China was discussed in order to provide an ideaology or a technical basis for maintaining the impetus of ecological restoration and economic development in this region. A case study was applied in combination with the theoretical analysis. The results indicated that the biomass productivity of the de-farming subsystem decreased by 38.4-72.3% compared with that of farming subsystem in the ecosystem. The main function of de-farming subsystem was focused on ecological productivity, it caused the ideal beneficial recycling ‘defarming → planting grass → raising animals → earn money＇ difficult to be realized. With the differentiation of de-farming subsystem, the natural and social resources input to the farming subsystem were accumulated. This laid a basis for the new attributes of economic productivity to be upgraded. The case study indicated that the economic productivity of the ecosystem was increased by 8.85-13.35 times due to re-coupling between the de-farming subsystem and the farming subsystem as well as coupling between microhabitat differentiation and crop production in the subsystems, where the microhabitat differentiation could enrich water and fertilizer in the same field. It was concluded that the important mechanisms to enhance the system productivity in the ecotone between agriculture and animal husbandry of North China included structure rebuilding and opening of the de-farming ecosystem and taking the advantage of complementary cooperative production among different regions under the market economy and rebuilding an open agro-pasture production structure,

Risk Assessment of Afforestation and Reforestation Processes

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.

Impacts of reforestation on woody species composition,species diversity and community structure in dry-hot valley of the Jinsha River,southwestern China

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.

Potential for carbon sequestration in reclaimed mine soil on reforested surface mining areas in Poland

Reclaimed mine soils (RMS) which develop on post-mining sites play significant role in Carbon sequestration in new ecosystems, especially in local range on areas disturbed by human activity. This study presents the potential for Carbon sequestration in RMS developing on 3 post sur- face mining areas in Poland (Central Europe) reforested with Scots pine (Pinus sylvestris L). Research was conducted on waste heaps and quarry which accompany open cast lignite, sul- fur, and sand mining. Control plots were arrang- ed in managed pine forests on natural sites in the surrounding area. The results shows high Carbon accumulation in RMS, estimated on 16.77 Mg?ha-1 in poor (oligotrofic) soils on Quaternary sands on sand quarry and up to 65.03 Mg?ha-1 on external waste heap after Sulfur sur- face mining exploitation on Quaternary sands mixed with Tertiary clays. These results were very similar to natural forest soils on control plots. Potential rate of Carbon sequestration in RMS was estimated on 0.73 (on the poorest sa- ndy soils on quarry) to 2.17 Mg?ha-1?yr-1 (on potentially abundant sandy-clayish soils on Sulfur waste heap), and 5.26 Mg?ha-1?yr-1 (on Tertiary sands substrate soils on lignite mining waste heap). In conslusion the average Carbon accu- mulation in RMS was estimated on 41 Mg?ha-1 and Carbon sequestration rate was 1.45 Mg? ha-1?yr-1. According to the result of this study and range of post-mining areas reclaimed to forestry in Poland (ca 15000 ha) total Carbon accumulation in RMS was estimated on 615 × 103 Mg and potential Carbon sequestration rate in new ecosystems on 21.75 × 103 Mg?ha-1?yr-1. However, the main factors affecting Carbon sequestration and protection in RMS under tree stand were substrate, percentage of clay and silt sized fraction, in order to formulate guidelines for sustainable management of post-mining ec- osystem, further study must be continue for be- tter understanding.

Evaluation of Honey Producing Potential of Robinia pseudacacia in Reforested Old Lignite Mines in West Macedonia

Opencast mining is important for local and global economy,but this operation mostly and inevitably leads to substantial environmental damage.Potential future use of the post-mining lands basically depends on the nature of the land,soil conditions,and communal structure of nearby surrounding to be rehabilitated by technical,biological,agricultural means or forestry applications.Vegetation cover has significant functions on post-mining landscapes so,in order to reduce the probability of negative impacts,selection of suitable plant material,which may be preferably native but also introduced plant species,is critical.In West Macedonia Lignite Centre,about 1,500 ha of these land has already reforested by the Public Power Corporation S.A.,with Robinia pseudacacia L.,one of the most criticized non-native tree species in Europe,because its rootstocks spread into neighbouring areas,repressing native species.The tree is an excellent species for revegetating poor or damaged soils and its fast-growing nature,makes it popular for former lignite mine reclamation,reforestation and erosion control.Robinia forests represent a valuable nectar and pollen source in late spring for many insects,especially Hymenoptera,such as Apis mellifera.That has increased dramatically the regional honey producing potential.In this study,the annual potential honey production of 1,500 ha black locust forests established in reforested old mines land,was estimated from 50,000 to 70,000 kg honey,depending on the year,which is sufficient for up to1,000 bee hives to survive for one year.For the efficient utilization of this valuable honey producing source by the beekeepers,a plan should be developed,to facilitate accessibility to the region and proper beehives dispersion.

养殖池塘退塘还林初期土壤有机碳及活性组分特征

海水养殖池塘退出养殖种植红树植物(退塘还林)是恢复红树林湿地及其生态系统碳汇功能的重要手段。为揭示退塘还林初期土壤有机碳库特征及其影响因素,阐明红树林湿地恢复过程中土壤碳库的动态变化,以广东省惠东县考洲洋海域退塘还林初期(红树种植2年)的池塘为研究对象,采集塘内红树种植岛、裸岛和水道3类样地0~100 cm的土壤柱状样品,比较分析了不同深度土壤有机碳(SOC)、活性有机碳[易氧化有机碳(EOC)、微生物有机碳(MBC)和可溶性有机碳(DOC)]含量差异及其与土壤因子间的相关性。结果表明:裸岛、红树种植岛和水道3类样地土壤0~100 cm SOC的质量分数分别为(7.92±0.43)、(7.72±0.35)和(7.48±0.69)g·kg^(-1),SOC密度分别为(84.56±3.65)、(72.01±3.20)和(70.12±1.44)Mg·hm^(-2);种植岛和裸岛土壤SOC峰值均出现在40~60 cm土层,深于水道样地(峰值出现在0~20 cm)。3类样地土壤活性有机碳组分EOC、MBC和DOC质量分数均为种植岛>水道>裸岛,种植岛土壤EOC和MBC峰值分别在40~60 cm和80~100 cm土层,深于水道和裸岛。土壤容重、总氮(TN)和总磷(TP)是活性有机碳含量及其垂直分布的关键影响因子,EOC和DOC与土壤容重和TP,以及MBC与TN间均呈极显著负相关(p<0.05)。研究表明,考洲洋退塘还林初期土壤活性有机碳组分占SOC比例较高,土壤碳库处于较活跃的状态;红树种植使土壤中下土层SOC活性组分含量增加,促进了有机碳向土壤深层迁移,随着红树植株的生长,其对土壤碳库和湿地碳汇的影响也将更加显著。

放牧压力对中国北方农牧交错带生态系统健康的影响

中国北方农牧交错带生态系统敏感脆弱、不稳定,其健康状况受多种因素影响,其中以放牧为代表的人类经济活动影响显著。高强度放牧是造成草地退化的重要原因,草地退化又是影响草原生态系统健康的关键因素。利用归一化植被指数和牲畜量量化放牧压力,并选取合理的模型探究放牧对于中国北方农牧交错带生态健康的影响,确定合理的放牧强度和策略,以实现草畜平衡和区域可持续发展。基于“活力-组织力-弹性-生态服务”(VORS)模型,构建起包括自然、社会等多方面的指标体系,评估了2000—2015年北方农牧交错带的生态健康系统水平,并采用Moran′s I探讨放牧压力和生态系统健康指数的空间相关性,并从普通最小二乘法、地理加权回归模型、时间加权回归模型和时空地理加权回归模型选择最优回归模型,揭示放牧压力对于生态系统健康的影响机制。结果表明:(1)2000—2015年放牧强度格局高值区域主要为内蒙古草原地区,低值区域主要为陕西高原地区。(2)2000—2015年中国北方农牧交错带的生态系统健康指数呈现上升趋势,区域整体处于亚健康状态和一般健康状态。(3)全局双变量Moran′s I结果显示在2000—2015年呈现负相关影响关系,但影响力度在变小。(4)多种回归模型相比较,GTWR模型表现最优。2000—2015年,正向驱动空间集中在内蒙古、辽宁以及山西省区县;负向驱动空间集中在陕西省、甘肃等区域,同时影响强度持续增强。研究通过不同区县、不同的草原的反应状况,提出放牧政策的不同实施建议,致力于实现草原资源的可持续利用和生态系统的持续健康。