Rebirth after death: forest succession dynamics in response to climate change on Gongga Mountain, Southwest China

Global climate change is having long-term impacts on the geographic distribution of forest species. However, the response of vertical belts of mountain forests to climate change is still little known. The vertical distribution of forest vegetation(vertical vegetation belt) on Gongga Mountain in Southwest China has been monitored for 30 years. The forest alternation of the vertical vegetation belt under different climate conditions was simulated by using a mathematical model GFSM(the Gongga Forest Succession Model). Three possible Intergovernmental Panel on Climate Change(IPCC) climate scenarios(increase of air temperature and precipitation by 1.8℃/5%, 2.8℃/10% and 3.4℃/15% for B_1, A_1B and A_2 scenarios, respectively) were chosen to reflect lower, medium and higher changes of global climate. The vertical belts of mountainous vegetation will shift upward by approximately 300 m, 500 m and 600 m in the B_1, A_1B and A_2 scenarios, respectively, according to the simulated results. Thus, the alpine tree-line will move to a higher altitude. The simulation also demonstrated that, in a changing climate, the shift in the vegetation community will be a slow and extended process characterized by two main phases. During the initial phase, trees of the forest community degrade or die, owing to an inability to adapt to a warmer climate. This results in modest environment for the introduction of opportunistic species, consequently, the vegetation with new dominant tree species becomes predominant in the space vacated by the dead trees at the expense of previously dominated original trees as the succession succeed and climate change advance. Hence, the global climate change would dramatically change forest communities and tree species in mountainous regions because that the new forest community can grow only through the death of the original tree. Results indicated that climate change will cause the change of distribution and composition of forest communities on Gongga Mountain, and this change may enhance as the intensity of climate change increases. As a result, the alternation of death and rebirth would finally result in intensive landscape changes, and may strongly affect the eco-environment of mountainous regions.

Characteristics of run off and sediment generation of forest vegetationon a hill slope by use of artificial rainfall apparatus

We studied the impact of forest vegetation on soil erosion, surface runoff, and sediment generation by using field simulated rainfall apparatus. We measured runoff and sediment generation of five 4.5 × 2.1 m runoff plots （a bare soil as a control; two Pinus tabulaeformis forest plots and two Platycladus orientalis forest with row spacing of 1 m × 1 m and 1.5 m× 1.5 m, respectively） in Beijing Jiu Feng National Forest Park under three rainfall intensities （0.42, 0.83, 1.26 mm per minute）. Forest vegetation significantly reduced soil erosion and sediment yield. Mean total runoff volume in the four tree stand plots was 93% of that in the control plot, demonstrating the limited effectiveness of forest vegeta- tion in runoff control. With increasing rainfall intensity, runoff reduction in forest plots declined from 28.32% to 2.1%. Similar trends in runoff coefficient and the relationship between runoffvolume and rainfall duration was observed. Mean total sediment yield and mean sediment yield reduction rate under different treatments was 55.05% and 43.17% of those in the bare soil control plot, respectively. Rainfall intensity played an important role in runoff and sediment generation processes, and had a greater impact on runoff than on soil erosion and sediment generation. When considering several factors in runoff and sediment transport processes, the P. tabulaeform plot with row spacing at 1 × 1 m had a greater effect on soil and water conservation than did other forested plots.

Effects of grazing on natural regeneration of tree and herb species of Kheyroud forest in northern Iran

We investigated the effects of grazing on natural regeneration, quantity, and diversity of woody species and dominant herb species in Kheyroud forest in northern Iran. We sampled vegetation in 5m2 plots in custom units, which are demarcated resource areas traditionally used by local livestock producers. The authors quantified number of species, height of seedlings, and diameter of seedlings. Height classes were 0-30 cm, 30-130 cm, and 〉130 cm, and diameter classes were 0-2.5 cm, 2.5-5 cm and 5-7.5 cm. The density of seedlings declined with distance from corral until reaching the custom unit boundary. Most seedlings had diameters of 0-2.5 cm and heights of 0-30 cm. Predominant species, Carpinus betulus and Acer capadocicum, were in plots near the centers of custom units, Fagus orientalis, Acer velutinum, Quercus castanifolia species were dominant in plots near the custom unit boundary. Plant species such as Oplismenus undulatifolius, Euphorbia amygdaloides, Rubusfrutieos and Pteridium aquilinum were dominant in plots nearer to forest corral. Healthy seedlings were more numerous in plots nearest the corral, while defective and deformed seedlings were more abundant away from the corral. We conclude that grazing had negative effects on the quantity and quality of vegetative regeneration. Continuation of overgrazing will not only endanger the sustainability of forest ecosystems, but also will increase the challenge of sustainable forest management.

Identification of Forest Vegetation Using Vegetation Indices

Spectral feature of forest vegetation with remote sensing techniques is the research topic all over the world, because forest plays an important role in human beings' living environment. Research on vegetation classification with vegetation index is still very little recently. This paper proposes a method of identifying forest types based on vegetation indices, because the contrast of absorbing red waveband with reflecting near-infrared waveband strongly for different vegetation types is recognized as the theoretic basis of vegetation analysis with remote sensing. Vegetation index is highly related to leaf area index, absorbed photosynthetically active radiation and vegetation cover. Vegetation index reflects photosynthesis intensity of plants and manifests different forest types. According to reflectance data of forest canopy and soil line equation NIR=1.506R+0.0076 in Jingyuetan, Changchun of China, many vegetation indices are calculated and analyzed. The result shows that the relationships between

Species diversity, regeneration and dominance as influenced by canopy gaps and their characteristics in tropical evergreen forests of Western Ghats, India

Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence of canopy gap size and the relationship of gap regime attributes to diversity measures and regeneration. The average gap size in the study area was found to be 396 m2 and around half of gaps were 4–8 years old. Gaps created by natural single tree fall were smaller in size but significantly higher in number. Diversity and regeneration of woody species were compared with canopy gaps and intact vegetation. Species richness and diversity was higher in gaps than in intact vegetation. Macaranga peltata, a shade intolerant species dominated gaps while intact vegetation was dominated by shade tolerant Kingiodendron pinnatum.Gap size significantly influenced species diversity and regeneration. Gap area and age were significantly and negatively correlated with diversity measures but positively correlated with regeneration. Among all the attributes of gaps, regeneration was significantly positively correlated with light intensity. Gaps maintained species diversity and favored regeneration of woody species. In addition to gap size and age, other gap ecological attributes also affected species diversity and regeneration.

Causal effects of shelter forests and water factors on desertification control during 2000–2010 at the Horqin Sandy Land region, China

The Horqin Sandy Land（HSL）, the largest sandy land in the semi-arid agro-pastoral ecotone of Northeast China, has been subject to desertification during the past century. In response, and to control the desertification,government implemented the Three-North Shelter/Protective Forest Program, world＇s largest ecological reforestation/afforestation restoration program. The program began in1978 and will continue for 75 years until 2050. Understanding the dynamics of desertification and its driving forces is a precondition for controlling desertification.However, there is little evidence to directly link causal effects with desertification process（i.e., on the changing area of sandy land） because desertification is a complex process,that can be affected by vegetation（including vegetation cover and extent of shelter forests） and water factors such as precipitation, surface soil moisture, and evapotranspiration.The objectives of this study were to identify how influencing factors, especially shelter forests, affected desertification in HSL over a recent decade. We used Landsat TM imagery analysis and path analysis to identify the effects of spatiotemporal changes in water and vegetation parameters during2000–2010. Desertification was controlled during the study period, as indicated by a decrease in desert area at a rate of163.3 km2year-1and an increase in the area with reduced intensity or extent of desertification. Total vegetation cover in HSL increased by 10.6 % during the study period and this factor exerted the greatest direct and indirect effects on slowing desertification. The contribution of total vegetation cover to controlling desertification increased with the intensity of desertification. On slightly and extremely severe desertified areas, vegetation cover contributed 5 and 42 % of the desertification reduction, respectively. There were significant correlations between total vegetation cover and water conditions（i.e., evapotranspiration and precipitation）and the area of shelter forests（P ／ 0.0001）, in which water conditions and the existence of shelter forests contributed49.7 and 12.8 % to total vegetation cover, respectively. The area of shelter forests increased sharply due to program efforts, but only shrub forests had significant direct effects on reducing the area of desertification categorized as slightly desertified. The reason for the lack of direct effect of increased arbor forests（accounting for 95.3 % of the total increase in shelter forests） on reducing desertification might be that the selected arbor species were not suited to water conditions（low precipitation, high evapotranspiration） prevailing at HSL. The establishment of shelter forests aided control of desertification in the HSL region, but the effect was less than expected. Effective control of desertification in the HSL region or other similar sandy areas will require greater improvements in vegetation cover. In particular,shrub species should be selected for plantation with reference to their potential to survive and reproduce in the harsh climatic and weather conditions typical of desertified areas.

The method on recovery of forest vegetation in degraded ecosystem in tropical and subtropical waste lowland in Guangdong

The aim of this paper is to discuss the reasonable method to set up the man-made ecosystem where the high productivity, high economic effects and ecological efficiencies, continual resources and suitable environment could be obtained.

Analysis of spatio-temporal changes in forest biomass in China

Forests play a central role in the global carbon cycle.China's forests have a high carbon sequestration potential owing to their wide distribution,young age and relatively low carbon density.Forest biomass is an essential variable for assessing carbon sequestration capacity,thus determining the spatio-temporal changes of forest biomass is critical to the national carbon budget and to contribute to sustainable forest management.Based on Chinese forest inventory data(1999–2013),this study explored spatial patterns of forest biomass at a grid resolution of 1 km by applying a downscaling method and further analyzed spatiotemporal changes of biomass at different spatial scales.The main findings are:(1)the regression relationship between forest biomass and the associated infuencing factors at a provincial scale can be applied to estimate biomass at a pixel scale by employing a downscaling method;(2)forest biomass had a distinct spatial pattern with the greatest biomass occurring in the major mountain ranges;(3)forest biomass changes had a notable spatial distribution pattern;increase(i.e.,carbon sinks)occurred in east and southeast China,decreases(i.e.,carbon sources)were observed in the northeast to southwest,with the largest biomass losses in the Hengduan Mountains,Southern Hainan and Northern Da Hinggan Mountains;and,(4)forest vegetation functioned as a carbon sink during 1999–2013 with a net increase in biomass of 3.71 Pg.

Development and evaluation of an individual tree growth and yield model for the mixed species forest of the Adirondacks Region of New York, USA

Background： Growth and yield models are important tools for forest planning. Due to its geographic location, topology, and history of management, the forests of the Adirondacks Region of New York are unique and complex. However, only a relatively limited number of growth and yield models have been developed and/or can be reasonably extended to this region currently. Methods： in this analysis, 571 long-term continuous forest inventory plots with a total of 10 - 52 years of measurement data from four experimental forests maintained by the State University of New York College of Environmental Science and Forestry and one nonindustrial private forest were used to develop an individual tree growth model for the primary hardwood and softwood species in the region. Species-specific annualized static and dynamic equations were developed using the available data and the system was evaluated for long-term behavior. Results： Equivalence tests indicated that the Northeast Variant of the Forest Vegetation Simulator （FVS-NE） was biased in its estimation of tree total and bole height, diameter and height increment, and mortality for most species examined. In contrast, the developed static and annualized dynamic, species-specific equations performed quite well given the underlying variability in the data. Long-term model projections were consistent with the data and suggest a relatively robust system for prediction. Conclusions： Overall, the developed growth model showed reasonable behavior and is a significant improvement over existing models for the region. The model also highlighted the complexities of forest dynamics in the region and should help improve forest planning efforts there.

Spatial Pattern of Forest Carbon Storage and Carbon Density in the Kanas National Natural Reserve

Based on the sub-forest management inventory, volume-derived biomass and mean biomass, carbon storage and its spatial distribution of forest vegetation in Kanas National Nature Reserve(hereinafter referred to as the Reserve) were calculated. The results showed that carbon storage of forest vegetation in the Reserve was 3.004 7 Tg C, mean carbon density was 49.58 Mg C/hm^2; carbon storage of different vegetation types: forest land >shrubbery > open forest > scattered trees, among which carbon storage of forest land accounted for 90.18% of the total carbon storage of the forest vegetation, and mean carbon density of forest land was 68.87 Mg C/hm^2; in terms of regional distribution, spatial distribution of carbon storage and carbon density declined from southwest to northeast; in the Reserve, carbon storage of mature and over-mature forest stands accounted for 79.89% of carbon storage of forest land. If scientifi c management is applied, carbon sequestration capacity of forest will be improved.

Classification System for Monitoring Historic Changes in Forest and Non-Forest Woody Vegetation—A Basis for Management

Forest and non-forest vegetation fulfils many non-productive and productive functions. A good understanding of the trajectories and drivers of the woody vegetation change is necessary for the relevant management. Recently, the number of studies devoted to monitoring forest cover changes has increased. However, these works do not fully distinguish between different categories of forest and non-forest woody vegetation. The main aim of the study was to propose a classification system for monitoring historic changes of woody vegetation in the landscape. The period of the last 150 years was mapped through three time-lines (1842, 1953 and 2011). Data were obtained by interpreting historic maps (Stable Cadastral map of 1842) and historical (1953) and current orthophoto (2011) using ArcGIS tools. The classification was applied on the example of Sokolov region (57 km2) located in western Bohemia. The result of the research is a proposal for classifying woody vegetation stands into four categories based on the structural and localisation criteria: (1) Line adjacent woodlands, (2) Landscape woodlands, (3) Settlement woodlands, and (4) Compact woodlands. Information on the woody vegetation development using the proposed classification system is important for understanding the patterns, pressures, and driving forces that led to the formation of the present-day forest and non-forest woody vegetation in the landscape. The results can also be applied as a basis for future forest management practice as they can be used in other different fields, e.g. history, archaeology etc.

Spatial distributions of intra-community tree species under topographically variable conditions

Growing public awareness of the importance of protecting biodiversity requires the development of forest practices that increase the complexity of stand structure.Understanding the ecological processes of different forest vegetation provide insights into community coexistence mechanisms.In this paper,the spatial patterns of three different communities,evergreen broadleaf forest,deciduous broadleaf forest,and mixed needleleaf and broadleaf forest at Mt.Huangshan,China,were quantified with four structural parameters,the mingling index,the uniform angle index,the diameter dominance index and the crowdedness index.All trees with a diameter at breast height of more than 5 cm were measured.Our analyses highlighted that most trees in the three communities were extremely dense and slightly clumped,with a moderate size differentiation and high mixed structure.In mixed needleleaf and broadleaf forest,the distribution pattern of tree species was better than the other two forests.Overall,spatial patterns in mixed needleleaf and broadleaf forest exhibited a strong stability-effect,that is,the stand had a suitable environment for the stable survival of the forest.With the increasing of elevation,the degree of the mingling index and the crowdedness index increased,however,there was no influence on the uniform angle index and the diameter dominance index.Further,at the same elevation,four structural parameters of shady slope were larger than that of sunny slope.Then we found the relationship between stand spatial structure and environment factors had important influence on forest structure.Our work contributes to the knowledge of population structure,and further provide theoretical basis for the sustainable development of forest resources and protecting biodiversity of Huangshan Mountain.In future studies,it is necessary to explore the limiting factors of community spatial distribution by combining species diversity and functional traits.

云南省抚仙湖流域森林植被及其水土保持价值研究(英文)

By using French SPOT5 satellite remote sensing image to contrast on the spot,the forest vegetation in Fuxian Lake basin was categorized into 23 forest types,6 vegetation subtypes,5 vegetation types,and the areas were respectively calculated.The tree species structure and the coverage degree of every kind of forest vegetation were investigated,and the characteristics of forest vegetation were analyzed.The results showed that the soil conservation amount of forest in Fuxian Lake basin was 137.50×106 t/a,and the soil conservation value was 622.30×106 yuan/a.Moreover,the water source conservation value was 506.84×106 yuan/a.

Altitudinal changes of surface pollen and vegetation on the north slope of the Middle Tianshan Mountains,China

To provide information on vegetation patterns and altitudinal distributions of pollen assemblage in surface soil layers,their complicated relationships in a dryland mountain-basin system in northwestern China and a realistic basis for paleovegetational reconstruction,we investigated 86 vegetation quadrats and analyzed 80 soil samples from the surface soil layers along an altitudinal transect on the north slope of the Middle Tianshan Mountains from alpine cushion vegetation at 3,510 m near glacier to desert vegetation at 460 m in the Gurbantunggut Desert.According to surface pollen assemblages and the results of the detrended correspondence analysis,the transect can be divided into six major altitudinal pollen zones as alpine cushion vegetation,alpine and subalpine meadows,montane Picea forest,forest-steppe ecotone,Artemisia desert and typical desert,which basically reflect the characteristics of the mountainous vegetation patterns on the north slope of the Middle Tianshan Mountains.However,Picea pollen also exists outside the spruce forest,Chenopodiaceae and Artemisia pollen appeared above the elevation of 1,300 m,indicating that most of them might be introduced from lower elevations by upslope winds.Airborne pollen researches from three regions at different elevations further suggest that a high-frequency northwest anabatic wind has a remarkable influence on the transportation and dispersion of surface pollen in the area.

Review of regional carbon counting methods for the Chinese major ecological engineering programs

In order to improve environment and relieve poverty, China has launched a series of major ecological engineering programs since the 1980 s. These include the Natural Forest Conservation Program, the Sloping Cropland Conversion Program, the Desertification Combating Program, and the Protection Forest System Construction Program. There is a growing need to quantify the contributions of these programs to regional carbon stocks.However, the lack of widely accepted, robust methods is one of the key obstacles to quantification. The objective of this study was to review existing methods for quantifying regional carbon stocks and then recommend suitable ones for the Chinese ecological engineering programs. We expect that the recommended methods can be applied to elsewhere in the world where there are similar characteristics and objectives.

Growth simulation of Fraxinus chinensis stands damaged by Hyphandria cunea in Beijing area

Hyphandria cunea is an insect that can damage hundreds of plants in its larval phase and needs to be placed under quarantine at an international level. Its hosts involve 600 plant species, including forest and fruit trees, shrubs, crops, vegetables, weeds and others. In 2006, we surveyed two Fraxinus chinensis Roxb stands, damaged to different degrees, after the invasion of H. cunea in the Changping district of the Beijing area. Given our survey of individual trees and investigation of bio-environmental factors, we pro-vide a preliminarily simulation of the growth situation of F. chinensis stands, damaged by H. cunea, by using the Forest Vegetation Simulator software （FVS）, which is supported by the ＂948＂ project from the State Forestry Administration of China. The results will provide a valuable reference in forecasting the effect of H. cunea and other invasive pests in China on forest ecological values.

Evapotranspiration estimation of Platycladus orientalis in Northern China based on various models

Platycladus orientalis is one of the most popular afforestation species and greening species for water management in arid and semi-arid regions of northern China. We applied various models to estimate and validate artificial P. orientalis forest evapotranspiration features with the goal of accurately estimating the water use of a P.orientalis plantation. The American Society of Civil Engineers Evapotranspiration–Penman–Monteith model（APM） and FAO56–Penman–Monteith model（FPM） are extensively applied for vegetation evapotranspiration estimation because their reliability has been validated by many scholars. The Priestley–Taylor model（PT） and Hargreaves model（HS） require only the daily maximum temperature,daily minimum temperature and solar radiation to estimate evapotranspiration and are thus widely applied to grasslands but not to forests. We used the Energy Balance Bowen Ratio（EBBR） system to validate the accuracy of the four models. The results indicated that：（1） Compared to the EBBR measurement annual value, APM was the most accurate, followed by FPM, and PT;（2） During the year, the accuracies of the four models varied. APM and FPM underestimated evapotranspiration during June, July and August, whereas PT and HS overestimated evapotranspiration during this period. In the rest of the year, the estimation accuracies were reversed;（3） An analysis of the possible reasons indicated that wind speed, air temperature and precipitation were the most important contributors.High temperatures were measured in June, July and August, which led to an overestimation by PT and HS because these two models only calculated the temperature and radiation without vegetation information. Underestimation also occurred when a low temperature was recorded. Though APM and FPM addressed both meteorological and vegetation factors, slight deviations still existed; and（4） The two models were modified based on EBBR-measured data. Relative humidity was introduced into PT, and parameter ‘‘A’’ in the HS estimation model was amended to1.41. The accuracy of the modified models significantly increased. The study highlighted the application, comparison and improvement of four models in estimating evapotranspiration and offers more approaches to assess forest hydrological functions.

The dynamic response of forest vegetation to hydro- thermal conditions in the Funiu Mountains of western Henan Province

This paper uses HJ-1 satellite multi-spectral and multi-temporal data to extract forest vegetation information in the Funiu Mountain region. The S-G filtering algorithm was employed to reconstruct the MODIS EVI（Enhanced Vegetation Index） time-series data for the period of 2000–2013, and these data were correlated with air temperature and precipitation data to explore the responses of forest vegetation to hydrothermal conditions. The results showed that：（1） the Funiu Mountain region has relatively high and increasing forest coverage with an average EVI of 0.48 over the study period, and the EVI first shows a decreasing trend with increased elevation below 200 m, then an increasing trend from 200–1700 m, and finally a decreasing trend above 1700 m. However, obvious differences could be identified in the responses of different forest vegetation types to climate change. Broad-leaf deciduous forest, being the dominant forest type in the region, had the most significant EVI increase.（2） Temperature in the region showed an increasing trend over the 14 years of the study with an anomaly increasing rate of 0.27℃/10a; a fluctuating yet increasing trend could be identified for the precipitation anomaly percentage.（3） Among all vegetation types, the evergreen broad-leaf forest has the closest EVI-temperature correlation, whereas the mixed evergreen and deciduous forest has the weakest. Almost all forest types showed a weak negative EVI-precipitation correlation, except the mixed evergreen and deciduous forest with a weak positive correlation.（4） There is a slight delay in forest vegetation responses to air temperature and precipitation, with half a month only for limited areas of the mixed evergreen and deciduous forest.

Developing a USLE cover and management factor(C)for forested regions of southern China

The Universal Soil Loss Equation model is often used to improve soil resource conservation by monitoring and forecasting soil erosion.This study tested a novel method to determine the cover and management factor(C)of this model by coupling the leaf area index(LAI)and soil basal respiration(SBR)to more accurately estimate a soil erosion map for a typical region with red soil in Hetian,Fujian Province,China.The spatial distribution of the LAI was obtained using the normalized difference vegetation index and was consistent with the LAI observed in the field(R^2=0.66).The spatial distribution of the SBR was obtained using the Carnegie-Ames-Stanford Approach model and verified by soil respiration field observations(R^2=0.51).Correlation analyses and regression models suggested that the LAI and SBR could reasonably reflect the structure of the forest canopy and understory vegetation,respectively.Finally,the C-factor was reconstructed using the proposed forest vegetation structure factor(Cs),which considers the effect of the forest canopy and shrub and litter layers on reducing rainfall erosion.The feasibility of this new method was thoroughly verified using runoff plots(R2=0.55).The results demonstrated that Cs may help local governments understand the vital role of the structure of the vegetation layer in limiting soil erosion and provide a more accurate large-scale quantification of the C-factor for soil erosion.