RELATIONSHIPS BETWEEN LARCH GROWTH AND FOREST SITE FACTORS

Dahurian larch (Larix gmelinii Rupr.) Rupr is one of the dominant species in bothnatural and man-made forests in northeast China.Effects of site factors,including topography,soilproperties and nutrient elements(P,Ca,K,Mg,Mn,Zn,Cu,Ag,Co and Ni)on the growth of larchwere analyzed in detail,qualitatively and quantitatively.The ordination technique was used to groupthe site factors and to classify sites for larch.Analysis indicated that height growth,diameter(DBH)and volume of the larch varied among site types and this will be of theoretical and practical signifi-canee in developing larch plantations.

Study on Mosuo's Sacred Natural Sites of Mountainous Forest and Protection of Biological Diversity in Yongning-Lugu Lake Area

With Mosuo's sacred natural sites of mountainous forest in Yongning-Lugu Lake area as the research subject,by using the method of ecology,the vegetation type in this area was initially identified.The control sample plot of the same vegetation type at similar altitude and in similar soil condition would be selected and compared with the sample plot in sacred natural sites at length,so as to quantitatively analyze the protection of biological diversity in the perspective of ecological system.It showed that under the circumstance of the damage of ecological environment,complete natural vertical pattern was preserved thanks to sacred natural sites of mountainous forest established by reason of traditional religion and culture.The results of research and quantitative analysis showed that compared with the control sample plot of the same vegetation type,sacred natural sites were high in biological diversity and the species composition of plant community in sacred natural sites was closer to that of primitive forest.The result of quantitative analysis also indicated that sacred natural sites played a remarkable role in protecting vegetation and this protective function became more remarkable if the altitude was higher.And human were reminded to pay close attention to the preservation and protection function of sacred natural sites to natural ecological system at high altitude.

Site Quality Evaluation for Mixed, Uneven-aged, Natural Forest Dominatedby Korean Pine in Northeast China

Six site types of Korean pine(Pinus koraiensis) forest, Mongolian oak type, Yezo spruce type, Korean spruce type, Amur linden type, Ribbed birch type and Manchurian ash type, are easily found on the south slope of Xiaoxing’an Mountains. The analysis results of H-A and H-Dbh relationships by site type showed that height growth of Korean pine dominant or codominant stems in natural stands is not directly related to its age but is directly related to its diameter, which closely accords with the Chapman-Richards equation(Relativity coefficients more than 0:8668). A method for evaluating site quality using height and diameter of dominant or codominant tree independent of tree age is examined. There are signifi-cantly differences in site quality of Korcan pine among six site types above. The site index was highest on Manchurian ash type, and lowest on Mongolian oak type. Differences of site index with a reference dbh of 40 cm between highest and lowest sites can reach 11 m in maximum., 7 m in average, respectively. Other rationales of the H-D method were discussed.

Site classification of the eastern forest region of Daxing'an Mountains

Based on the plot data from the investigation and the theory of forest ecology and ecological system,the site classification of the eastern forest region of Daxing’an Mountains was made by mean of mathematical method. The main factors were slope, thickness of soil layer, slope position and slope aspect. Grades of slope were used as the division standard for site type group. The slope aspect, slope position and thickness of soil layer were used as the division standards for site type. Altogether 7 site type groups and 15 main site types were determined the region. It provided reliable fundamental basis for the reasonable management and planting design in the area.

Growth models and site index table of natural Korean pine forests

According to the growth characteristics of natural Korean pine (Pinus Koraiensis) forests, 6 equations such as Chapman-Richards equation, Logistic equation, Power equation, and so on were selected to ftt for the growth modeIs for Korean pine forest. The growth models were developed based on 208 random trees and 24o dominant trees. Results show that the Chapman-Richards equation is the best model for estimating tree height by age and DBH, while the Parabola equation is fittest for predicting DBH by age or estimating age from DBH. The site index table of Korean pine forest was compiled by using the proportional method with the Chapman-Richards equation as the guide curve and vaIidated by accuracy test.

SITE CLASSIFICATION FOR PROTECTIVE FOREST AFFORESTATION ON THE COAST OF CHINA

Land for protective forest on the coast has special site conditions, and site classification is the scientific basis for seaboard afforestation. The site classification system on the coast zone and islands of China may be classified into five levels-site region (sub - region), district, class, group, and type. The land division for afforestation is carried out by the principle of enviornmental heterogeneity among regions, sub-region and district on large scale, according to the difference of air temperature, moisture and type of coast geomorphy. It may be classified into 7 regions, 12 sub-regions and 55 districts. The medium and small scaled division for site class, group and type, subdivided in a site district, are based on medium topography, topographic climate, micro - relief and soil conditions.

Application of site-specific biomass models to quantify spatial distribution of stocks and historical emissions from deforestation in a tropical forest ecosystem

Allometric equations developed for the Lama forest, located in southern Benin, West Africa, were applied to estimate carbon stocks of three vegetation types：undisturbed forest, degraded forest, and fallow. Carbon stock of the undisturbed forest was 2.7 times higher than that in the degraded forest and 3.4 times higher than that in fallow. The structure of the forest suggests that the individual species were generally concentrated in lower diameter classes. Carbon stock was positively correlated to basal area and negatively related to tree density, suggesting that trees in higher diameter classes contributed significantly to the total carbon stock. The study demonstrated that large trees constitute an important component to include in the sampling approach to achieve accurate carbon quantification in forestry. Historical emissions from deforestation that converted more than 30% of the Lama forest into cropland between the years 1946 and 1987 amounted to 260,563.17 tons of carbon per year（t CO2/year） for the biomass pool only. The study explained the application of biomass models and ground truth data to estimate reference carbon stock of forests.

Impact of site management on changes in soil carbon after afforestation:A review

Afforestation and forest management can increase carbon stocks and account for emission reduction according to the Kyoto Protocol. Site management has important effects on the accumulation of soil carbon after afforestation. This review examines the effects of site management, including soil disturbance, fertilization, thinning, weed control, harvesting and controlled burning, on soil carbon dynamics in plantations, based on recent published results. Soil disturbance can enhance soil carbon losses, with whole ploughing causing the most and disking the least loss of soil carbon. The effects of fertilization and thinning on soil carbon are in- conclusive. Weed control can prevent the carbon input from above-grotmd residue and root turnover and increase soil temperature and soil erosion, which in turn reduces the amount of carbon on the soil surface. Soil carbon decreases with the increase of harvest- ing intensity and the retention of harvest residue can significantly enhance the accumulation of carbon in the soil. Controlled burning before afforestation has a short-term benefit for soil carbon, but it is not beneficial to the sequestration of soil carbon over the long term. Future studies should focus on investigating the long-term impact of site management practices, especially soil fertilization and thinning, on carbon, identifying the response of major functional pools of soil carbon to management practices, understanding the dy- namics of soil nitrogen pools and their role in long-term soil carbon sequestration, as well as quantifying soil carbon processes under different climate conditions and site management scenarios using models.

Geostatistical Approach for Site Suitability Mapping of Degraded Mangrove Forest in the Mahakam Delta, Indonesia

As part of operational guidance of mangrove forest rehabilitation in the Mahakam delta, Indonesia, site suitability mapping for 14 species of mangrove was modelled by combining 4 underlying factors—clay, sand, salinity and tidal inundation. Semivariogram analysis and a geographic information system (GIS) were used to apply a site-suitability model, while kriging interpolation generated surface layers, based on sample point data collection. The tidal inundation map was derived from a tide table and a digital elevation model from topographic maps. The final site-suitability maps were produced using spatial analysis technique, by overlaying all surface layers. We used a Gaussian model to adjust a semivariogram graph in order to help to understand the variation of sample data values, and create a natural surface layer of data distribution over the area of study. By examining the statistical value and the visual inspection of surface layers, we saw that the models were consistent with the expected data behavior;therefore, we assumed that interpolation has been carried out appropriately. Our site-suitability map showed that Avicennia species was the most suitable species and matched with 50% of the study area, followed by Nypa fruticans, which occupied about 42%. These results were actually consistent with the mangrove zoning pattern in the region prior to deforestation and conversion.

The composition and diversity of natural regeneration of tree species in gaps under different intensities of forest disturbance

The positive ecological interaction between gap formation and natural regeneration has been examined but little research has been carried out on the effects of gaps on natural regeneration in forests under different intensities of disturbance.This study evaluates the composition,diversity,regeneration density and abundance of natural regeneration of tree species in gaps in undisturbed,intermittently disturbed,and disturbed forest sites.Bia Tano Forest Reserve in Ghana was the study area and three gaps each were selected in the three forest site categories.Ten circular subsampling areas of 1 m2 were delineated at 2 m spacing along north,south,east,and west transects within individual gaps.Data on natural regeneration<350 cm height were gathered.The results show that the intensity of disturbance was disproportional to gap size.Species diversity differed significantly between undisturbed and disturbed sites and,also between intermittently disturbed and disturbed sites for Simpson’s(1-D),Equitability(J),and Berger-Parker(B-P)indices.However,there was no significant difference among forest sites for Shannon diversity(H)and Margalef richness(MI)indices.Tree species composition on the sites differed.Regeneration density on the disturbed site was significantly higher than on the two other sites.Greater abundance and density of shade-dependent species on all sites identified them as opportunistic replacements of gap-dependent pioneers.Pioneer species giving way to shade tolerant species is a natural process,thus make them worst variant in gap regeneration.

中英风景名胜区/国家公园自然旅游规划管治模式比较——以中国九寨沟国家级风景名胜区和英国New Forest(NF)国家公园为例

介绍了中英两国国家公园规划管治体系的基本组织机构、要求和层次。分别对2个案例地——中国九寨沟国家级风景名胜区和英国New Forest国家公园的旅游规划管治背景、现状及内容体系进行了比较分析,总结了中英两国国家公园自然旅游规划管治模式的差异、特征,并进行了原因解析。最后基于比较分析的研究结论提出了英国国家公园管理对我国风景区旅游规划管理的若干启发和措施建议。

Estimating the productive potential of five natural forest types in northeastern China

Background: There is a serious lack of experience regarding the productive potential of the natural forests in northeastern China, which severely limits the development of sustainable forest management strategies for this most important forest region in China. Accordingly, the objective of this study is to develop a first comprehensive system for estimating the wood production for the five dominant forest types.Methods: Based on a network of 384 field plots and using the state-space approach, we develop a system of dynamic stand models, for each of the five main forest types. Four models were developed and evaluated, including a base model and three extended models which include the effects of dominant height and climate variables. The four models were fitted, and their predictive strengths were tested, using the "seemingly unrelated regression"(SUR) technique.Results: All three of the extended models increased the accuracy of the predictions at varying degrees for the five major natural forest types of northeastern China. The inclusion of dominant height and two climate factors(precipitation and temperature) in the base model resulted in the best performance for all the forest types. On average, the root mean square values were reduced by 13.0% when compared with the base model.Conclusion: Both dominant height and climate factors were important variables in estimating forest production. This study not only presents a new method for estimating forest production for a large region, but also explains regional differences in the effect of site productivity and climate.

Choice of Species in China's Plantation Forestry

This paper reviews the new developments in the choice of tree species for China’s plantation forestry in relation to forest regionalization and site classification. After a brief discussion on the fundamental principles of choosing species,it gives the statistical data of the species composition of established forest plantations and recommendation for suitable tree species for plantations in some important forestry regions. Results of studies in 3 different cases have been given to illustrate the research approach in choice of tree species in accordance with the planting sites.

Soil Genesis of Four Alfisols Established in Oak Hickory Forests along Drainages into the Mississippi River in Southeastern Missouri, USA

Alfisols in USA taxonomy are “deciduous forest” soils having an argillic horizon with a base saturation in the control section greater than 35%. Alfisols are geographically extensive and support productive agriculture and deciduous forest ecosystems. Understanding Alfisol genesis, including the presence and intensity of the dominant soil processes, facilitates best management practices that provide stewardship for these soil resources and improves forest and agriculture productivity. Four Alfisols, presently having mature forest settings and located in the central United States along the Mississippi River, were selected for soil and landscape description, classification, and delineation of the dominant soil forming processes. Excavated soils were described and routinely sampled for subsequent physical, chemical, and mineralogical analysis. An aqua regia digestion protocol provided elemental analysis for identifying and inferring the intensity of soil forming processes. The dominant soil forming factors include 1) organic matter accumulation, 2) clay eluviation-illuviation, 3) acidification, 4) base cation accumulation in the A horizons by the forest vegetation, 5) Fe-oxyhydroxide formation, and 6) clay mineral synthesis. Two soils were developed entirely in Peoria loess and two soils were developed in Peoria Loess overlying Ordovician limestone residuum. Ecological site descriptions provide land managers information for evaluating land suitability and the capability to implement different management activities without ecosystem disturbance. Best management practices for the described landforms and based on their Ecological Site Descriptions are presented.

Site Productivity of Clone and Seed Raised Plantations of <i>Eucalyptus urophylla</i>and <i>Eucalyptus grandis</i>in Southeast Mexico

The relationship between soil variables and forest productivity of Eucalyptus urophylla (Eu) and E. grandis (Eg) was studied in commercial forest plantations (CFP) in Huimanguillo, Tabasco, Mexico. The group of Eu included seed and clone raised plantations and the Eg group included only seed raised plantations. Tree measurements and soil sampling were carried out at 56 500-m2 plots. Two soil depths (0 - 20 and 20 - 40 cm) were sampled and analyzed for physical and chemical properties. Site Index (SI), calculated at year 14 was used as indicator of forest productivity. Simple correlation, multiple and second order regressions were used to test the effect of soil variables on productivity. Results showed that mean annual increments (MAI) of Eu and Eg were comparable to other regions of the world reaching 49 m3·ha-1·y-1 across a range of low to high soil fertility gradient (15 to 80 m3·ha-1·y-1). For both species, regardless of the production method (seed or clone), soil texture was the most relevant variable to explain variation in productivity. Eu productivity was correlated to exchangeable Mg (0.3) and Al (0.3) in the 0 - 20 cm soil depth and CEC (0.4) and exchangeable Al (0.6) in the 20 - 40 cm soil depth. Compared to clone plantations, seed plantations showed higher correlations between soils properties and productivity. Aluminum saturation was negatively related to Eg productivity. The highest correlation between soil and productivity were found for Eg, with soil P-availability and aluminum saturation explaining 82 and 85% of the variation, respectively. This works shows that low fertility soils, previously used as pasturelands can be productive for forest plantation purposes and contribute to carbon sequestration.

The effect of water-level fluctuations on swamp forest colonization by seedlings of <i>Tabebuia cassinoides</i>DC. (Bignoniaceae)

Establishment of Tabebuia cassinoides seedlings is related to water-level fluctuations in southeastern Brazil swamp forests. Nine years of annual monitoring of 48 individuals established during a drought in November 1997, when the swamp was unflooded, suggested that their establishment depends on this unpredictable event. This conclusion is further sustained by the wide variability of the seedling cohort size structure, and the fascicular root conformation that holds the shoots erect.

Mixed-Species Allometric Equations to Quantify Stem Volume and Tree Biomass in Dry Afromontane Forest of Ethiopia

Volume and biomass equations are essential tools to determine forest productivity and enable forest managers to make informed decisions. However, volume and biomass estimation equations are scarce for Afromontane forests in Africa in general and Ethiopia in particular. This limits our knowledge of the standing volume of wood, biomass, and carbon stock of the forests therein. In this study, we developed a new mixed-species volume and biomass equations for Afromontane forests and compared them with generic pantropical and local models. A total of 193 sampled trees from seven dominant tree species were used to develop the equations. Various volume and biomass equations were fitted using robust linear and nonlinear regression. Model comparison indicated that the best model to estimate stem volume was ln(v)=-9.909+ 0.954*ln(d2h), whereas the best model to estimate biomass was ln(b)=-2.983+ 0.949*ln(ρd2h) . These equations explained over 85% of the variations in the stem volume and biomass measurements. The mean density and basal area of trees in the forest with d ≥ 2 cm was 631.5 stems·ha-1 and 24.4 m2·ha-1. Based on the newly developed equations, the forest has on average 303.0 m3·ha-1 standing volume of wood and 283.8 Mg·ha-1 biomass stock. The newly developed allometric equations derived from this study can be used to accurately determine the stem volume, biomass, and carbon storage in the Afromontane forests in Ethiopia and elsewhere with similar stand characteristics and ecological conditions. By contrast, the generic pan-tropical and other local models appear to provide biased estimates and are not suitable for dry Afromontane forests in Ethiopia. The estimated stem biomass and carbon stock in the Chilimo forest are comparable with the estimates from various tropical forests and woodlands elsewhere in Africa, indicating the importance of dry Afromontane forest for climate change mitigation.

混交对杉木和山杜英混交林生长、结构和生产力的影响

为探究杉木(Cunninghamia lanceolata)与山杜英(Elaeocarpus sylvestris)的混交效应,以景德镇枫树山林场20年生杉木纯林、山杜英纯林和杉木-山杜英混交林为研究对象,每种林分类型设置3种坡位(上坡、中坡和下坡),分析树种混交对林分生长的影响,并分别探究混交效应对立地条件和生境因子的响应。结果表明:混交林蓄积较预期蓄积增加5%,表现略微增产;混交林中杉木蓄积较杉木纯林增加15%,混交林中山杜英蓄积较山杜英纯林减少13%。相对于纯林,两树种直径分布特征对混交的响应呈相反趋势,混交林中杉木直径分布峰值向高阶移动,而混交林中山杜英直径分布峰值向低阶移动。混交林及其纯林粗根直径-胸径的异速生长分析表明,混交林中杉木生长侧重于树干生长,而山杜英生长侧重于根系生长;无论林型和树种,坡位由上到下,林木生长会侧重于树干生长。杉木-山杜英混交效应与地位指数呈显著负相关(P<0.05),土壤有效磷是混交林生长的主要限制因子。杉木与山杜英混交可促进林分生长,且混交林对较差立地条件有更好的适应性。

Soil quality index as a tool for Scots pine(Pinus sylvestris) monoculture conversion planning on afforested,reclaimed mine land

In Central Europe, a large portion of post-mining sites were afforested with Scots pine, which is characterized by good adaptability and a tolerance for poor habitat at the beginning of forest ecosystem development. Conversion of monoculture on mine sites into more biodi- verse mixed hardwood forests, especially on more fertile deposits, can be an emerging need in this part of Europe in next decades. The ability to classify the forests at these post-mining sites will facilitate proper species selection as well as the management and formation of the developed ecosystem＇s stability. This work describes the guidelines that can be followed to assess reclaimed mine soil （RMS） quality, using the mine soil quality index （MSQI） and a classification of developed forest sites as a basis of tree-stand species selection and conversion of pine monocul- tures. The research was conducted on four post-mining facilities （lignite, hard coal, sulphur, and sand pit mining areas） on different RMS sub- strates dominant in Central Europe. Soil quality assessment takes into account the following features of the soil： texture soil nutrients （Ca, Mg, K, Na, P）; acidity （pH KC1）; and Corg-to-Nt ratio in the initial organic horizon. An analysis was conducted of classification systems using the MSQI validation correlation （at p =0.05） with vegetation features af- fected by succession： aboveground biomass of forest floor and ecological indicators of vascular plants （calculated on the basis of EUenberg＇s （2009） system）. Eventually, in the analysed data set, the MSQI ranged from 0.270 for soils on quaternary sands to 0.720 for a mix of quaternary loamy sands with neogene clays. Potential forest habitat types and the role of the pine in the next generation of tree stands on different RMS parent rock substrate were proposed.

西北地区红桦天然次生林立地质量评价

在陕西、宁夏、甘肃、青海等地设置红桦天然次生林临时样地85块,以年龄-树高、胸径-树高数据为依据,选取常用的9个树木生长模型拟合导向曲线,采用相对优势高法编制立地指数表和立地形表,并采用2种方法对4个不同地区的立地质量进行比较,实现对西北地区红桦天然次生林立地质量的科学评价。结果表明,立地指数和立地形的最优导向曲线方程分别为H=18.073/{1+exp[-(A-22.571)/9.144]}、H=19.793/{1+exp[-(D-12.218)/6.588]};确定基准年龄为40 a,基准胸径为20 cm,指数级距为2 m,划定10~20 m共6个立地质量等级,编制立地指数表和立地形表。检验结果表明,两表的卡方值均小于临界值,落点检验精度分别为95%和97.5%,达到编表精度要求,均能够良好地反映红桦天然次生林立地质量。2种方法在对4个地区的立地质量评价中表现出较好的一致性,其中陕西火地塘林场立地质量最优,宁夏二龙河林场次之,青海北山林场和甘肃洮坪林场立地质量一般。