Main Forest Types Research Articles

The Data on Remote Sensing and Possibility of their use to Evaluate the Performance of Forest Ecosystems in Mountain Territories (a Case Study of the Kabardino-Balkar Republic)

The quantitative data on dynamics of areas in main forest types (pine, birch, hornbeam, beech and oak forests) of Kabardino-Balkaria for 20 years since 1986 are obtained from the analysis of hyper spectral Landsat 5 TM space images. To calculate forest areas, the digital terrain model built on SRTM-fi le and two-dimensional Landsat 5 TM cosmic images is used. The signifi cant reduction of beech cenosis (23.4%) and birch cenosis (21.9%) is revealed. Reafforestation has resulted from increasing area of oak and hornbeam stands. Researches show that it is necessary to consider the gradient of slopes to calculate the area. Estimations of the areas calculated on three-dimensional terrain model and two-dimensional cosmic images for coniferous and parvifoliate forests of Kabardino-Balkaria, most of which are located on the slopes with 20–40o gradients and at the altitudes up to 2500 m, differ by 15–20%. For oak forests the difference isn’t so signifi cant (2.2%) as most of them are located on gentle slopes. The obtained data on total forest area as well as on areas of particular forest types differ essentially from literary and official information

The Use of a Modified GOPCE Method for Forest and Nonforest Discrimination

This study focuses on the development and evaluation of the generalized optimization of polarimetric contrast enhancement (GOPCE) model to discriminate between forested and nonforested areas. The main objective is to investigate the performance of the GOPCE method for forest mapping and to assess the potential of different polarimetric parameters for forest representation. We make two modifications to the original GOPCE method. First, by comparing behaviors of different polarimetric parameters, the GOPCE model is modified. Then, linear discriminant analysis is employed for further optimization of the target contrast. Forest/nonforest discrimination results are demonstrated on L-band fully polarimetric ALOS-1/PALSAR data acquired over a pilot study area in northeastern Tasmania, Australia, where the main forest type is eucalypt forests. Two other forest classification approaches (i.e., support vector machine and canonical variate analysis) are also tested for comparison. The final results obtained from the modified GOPCE model with the generalized Fisher criterion can improve the forest/nonforest discrimination accuracy.

Prediction of forest NPP in Italy by the combination of ground and remote sensing data

Our research group has recently proposed a strategy to simulate net forest carbon fluxes based on the coupling of a NDVI-driven parametric model, Modified C-Fix, and of a biogeochemical model, BIOME-BGC. The outputs of the two models are combined through the use of a proxy of ecosystem distance from equilibrium condition which accounts for the occurred disturbances. This modeling strategy is currently applied to all Italian forest areas using an available set of NDVI images and ancillary data descriptive of an 8-year period (1999–2006). The obtained estimates of forest net primary production (NPP) are first analyzed in order to assess the importance of the main model drivers on relevant spatial variability. This analysis indicates that growing stock is the most influential model driver, followed by forest type and meteorological variables. In particular, the positive influence of growing stock on NPP can be constrained by thermal and water limitations, which are most evident in the upper mountain and most southern zones, respectively. Next, the NPP estimates, aggregated over seven main forest types and twenty administrative regions in Italy, are converted into current annual increment of standing volume (CAI) by specific coefficients. The accuracy of these CAI estimates is finally assessed by comparison with the ground data collected during a recent national forest inventory. The results obtained indicate that the modeling approach tends to overestimate the ground CAI for most forest types. In particular, the overestimation is notable for forest types which are mostly managed as coppice, while it is negligible for high forests. The possible origins of these phenomena are investigated by examining the main model drivers together with the results of previous studies and of older forest inventories. The implications of using different NPP estimation methods are finally discussed in view of assessing the forest carbon budget on a national basis.

Characteristics of nitrogen and phosphorus stoichiometry across components of forest ecosystem in Shaanxi Province

Aims Nitrogen(N) and phosphorus(P) stoichiometry between vegetation, litter, and soil were important for understanding biogeochemical cycles in terrestrial ecosystems, but remain poorly understood. Here, our aims were to study characteristics of N and P stoichiometry for the plant, litter, and soil and the interactions between its components across forest ecosystems in Shaanxi Province. Methods A total of 121 sampling sites, covering the most main forest types in Shaanxi, were established across the whole province in 2012. And N and P concentration of vegetation(tree and understory), litter and soil layers were measured for each site. Important findings 1) There were significant differences in the N and P stoichiometry among the forest ecosystem components(p 0.05). N and P contents were higher in understory and litter layer, and lower in tree and soil. Whereas the N:P was slightly different, highest in litter and lowest in the soil layer, with little differences among remaining components. The contents of N, P and N:P ranged from 0.72 to11.99 mg·g–1, 0.47 to 1.07 mg·g–1, and 1.86 to 14.84, respectively. Within top 1 m soil layer N content and N:P decreased with soil depth(p 0.05), however the P content did not exhibit significant changes. 2) N and P contents, and N:P of each component were higher in broadleaf forest than in coniferous forest, although the difference is not significant. 3) N was positively correlated with P content except for soil and N:P was negatively correlated with P content, but positively correlated with N content within each component. In addition, there was a significant positive correlation for N and Pstoichiometric characteristics between litter layer and tree, herb, soil layer. 4) Although spatial pattern of N and P contents, and N:P differed in relation to longitude, latitude, and elevation for forest ecosystem components, a stable distribution was exhibited in general.

川中丘陵区柏木低效林改造模式植物多样性对土壤有机碳的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 川中丘陵区柏木低效林改造模式植物多样性对土壤有机碳的影响 DOI: 10.5846/stxb201307181913 作者: 作者单位: 四川农业大学林学院 长江上游林业生态工程四川省重点实验室 四川 雅安 625014,雅安市林业局,四川农业大学林学院 长江上游林业生态工程四川省重点实验室 四川 雅安 625014,四川农业大学林学院 长江上游林业生态工程四川省重点实验室 四川 雅安 625014,四川农业大学林学院 长江上游林业生态工程四川省重点实验室 四川 雅安 625014,四川农业大学林学院 长江上游林业生态工程四川省重点实验室 四川 雅安 625014 作者简介: 通讯作者: 中图分类号: 基金项目: 国家"十二五"科技支撑项目(2011BAC09B05);国家林业局中央财政林业科技推广示范(2010TK55);四川省科技支撑计划(2010NZ0049)共同资助 Effects of plant diversity on soil organic carbon under different reconstructing patterns in low efficiency stands of cuprssus funebris in the hilly region of central Sichuan Author: Affiliation: College of Forestry,Sichuan Agricultural University,Forestry Ecological Engineering in Upper Reaches of Yangtze River Key Laboratory of Sichuan Province,Ya’an,Forestry Bureau of Ya'an,College of Forestry,Sichuan Agricultural University,Forestry Ecological Engineering in Upper Reaches of Yangtze River Key Laboratory of Sichuan Province,Ya’an,College of Forestry,Sichuan Agricultural University,Forestry Ecological Engineering in Upper Reaches of Yangtze River Key Laboratory of Sichuan Province,Ya’an,College of Forestry,Sichuan Agricultural University,Forestry Ecological Engineering in Upper Reaches of Yangtze River Key Laboratory of Sichuan Province,Ya’an,College of Forestry,Sichuan Agricultural University,Forestry Ecological Engineering in Upper Reaches of Yangtze River Key Laboratory of Sichuan Province,Ya’an Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以川中丘陵区柏木低效林改造10a后的4种模式:纯杂交竹模式(Bambusa pervariabilis × Dendrocalamopsis daii)(CZ)、柏木(Cupressus funebris Endl.)+桤木(Alnus cremastogyne Burk.)+杂交竹模式(BZQ)、柏木+麻栎(Quercus acutissima Carruth)模式(BL)、柏木+杂交竹模式(BZ)为研究对象,纯柏(CB)为对照,对土壤有机碳含量、碳密度和土壤活性有机碳(土壤易氧化碳、水溶性碳和微生物量碳)含量及植物多样性进行了研究。结果表明:(1)随着土层深度的增加,土壤有机碳含量、碳密度及其组分均下降,其中土壤有机碳含量下降幅度最大,易氧化碳含量下降幅度最小;0-10 cm土壤有机碳密度占整个取样剖面的45.7%-64.4%,具有明显的表聚性。(2)不同模式0-40 cm土层土壤有机碳含量、碳密度和土壤易氧化碳、水溶性碳和微生物量碳含量均为BZQ > BZ > CB > BL > CZ,差异均达到显著水平(P < 0.05)。几种模式中,BZQ与CB相比,土壤有机碳含量、碳密度、土壤易氧化碳、水溶性碳和微生物量碳含量增幅分别为37.8%、33.5%、36.6%、52.5%和23.2%,表明BZQ模式在提高土壤有机碳方面作用最明显。(3)植物Simpson优势度指数、Shannon-Wiener多样性指数、Pielou均匀度指数和丰富度指数大致表现为BZQ > BZ > CB > BL > CZ;相关分析表明,土壤有机碳、碳密度、易氧化碳、水溶性碳和微生物量碳与灌木层和草本层的植物多样性指数均呈显著正相关,而与乔木层植物多样性不相关。 Abstract:The soil organic carbon (SOC) pool is an important component of global carbon stock, It could play a huge impact on global terrestrial carbon cycling, eco-system construction and material recycling due to its slight changes. Plant diversity could influence the temperature, humidity, microorganisms and litter of forest floor, and then affect the reserves of SOC. The hilly region in central Sichuan province is a critical part of ecological barriers in the upper reaches of the Yangtze River, and the low efficiency stands of Cuprssus funebris grow in these areas are the main forest types. Our objectives were (1) to explore the characteristics of SOC in the low efficiency stands of Cuprssus funebris which have been reconstructed for 10 years, (2) to quantify the relationships between SOC and plant diversity of the tree layers, the shrub layers and the herb layers.The planting patterns of Bambusa pervariabilis×Dendrocalamopsis daii (CZ), Cupressus funebris Endl.+Bambusa pervariabilis×Alnus cremastogyne Burk.+ Alnus cremastogyne Burk. (BZQ), Cupressus funebris Endl.+Quercus acutissima Carruth (BL), Cupressus funebris Endl.+Bambusa pervariabilis× Dendrocalamopsis daii (BZ) were reconstructed in 2002. CZ pattern was reconstructed on the planting spacing of 4 m×4 m after clear cutting, and the other patterns were reconstructed by interplanting after intermediate cutting. In 2012, 3 sample plots were set in each pattern to study SOC content, SOC density, easily-oxidized carbon (EOC), water-soluble organic carbon (WSOC), soil microbial biomass carbon (SMBC) and plant diversity. The results were found as follows: (1) The contents of SOC and its components were decreased with increasing soil depth, with the maximal drop of SOC and the minimum drop of EOC; SOC density in topsoil (0-10 cm) accounted for 45.7% to 64.4% of the whole sampling profile, exhibiting obvious surface accumulation. (2) SOC content, SOC density, EOC, WSOC and SMBC content in 0-40 cm were in the order of BZQ > BZ > CB > BL > CZ, with significant differences (P < 0.05). Compared with CB, the increase rates of SOC content, SOC density, EOC, WSOC and SMBC content were 37.8%, 33.5%, 36.6%, 52.5% and 23.2%, respectively, and BZQ revealed the most obvious effect on SOC. (3) The index of species dominance, species diversity, species evenness and species richness were roughly arranged as BZQ > BZ > CB > BL > CZ. There were significant positive correlation between SOC content, SOC density, EOC, WSOC and SMBC content and the plant diversity of shrub and herbaceous layers, while the correlation were not significant between SOC and its components and the plant diversity of tree layer. It indicated that the effects of the diversity of herbaceous and shrub layers on SOC were more obvious than those of the other tree layers. The most obvious influence on the improvement of SOC content was BZQ pattern, and thus this pattern was proposed to promote. Due to the vegetational transformation in the studied region is still in its initial stage, vegetation succession will continue and in a unstable state, therefore, it will be more meaningful to provide a theoretical basis for the transformation of low efficiency stands of Cupressus funebris. 参考文献 相似文献 引证文献

The conservation value of degraded forests for agile gibbons Hylobates agilis

All gibbon species are globally threatened with extinction yet conservation efforts are undermined by a lack of population and ecological data. Agile gibbons (Hylobates agilis) occur in Sumatra, Indonesia and adjacent mainland Southeast Asia. Population densities are known from four sites (three in Sumatra) while little is known about their ability to tolerate habitat degradation. We conducted a survey of agile gibbons in Harapan Rainforest, a lowland forest site in Sumatra. The area has been severely degraded by selective logging and encroachment but is now managed for ecosystem restoration. We used two survey methods: an established point count method for gibbons with some modifications, and straight line transects using auditory detections. Surveys were conducted in the three main forest types prevalent at the site: high, medium, and low canopy cover secondary forests. Mean group density estimates were higher from point counts than from line transects, and tended to be higher in less degraded forests within the study site. We consider points more time efficient and reliable than transects since detectability of gibbons was higher from points per unit effort. We recommend the additional use of Distance sampling methods to account for imperfect detection and provide other recommendations to improve surveys of gibbons. We estimate that the site holds at least 6,070 and as many as 11,360 gibbons. Our results demonstrate that degraded forests can be extremely important for the conservation of agile gibbons and that efforts to protect and restore such sites could contribute significantly to the conservation of the species.

Classification of Korean forests: patterns along geographic and environmental gradients

AbstractAimTo describe the main vegetation types of the Korean zonal forests and explore their relationship with the main environmental and geographic gradients.LocationKorean Peninsula.MethodsA data set of 3847 relevés of zonal (semi)natural forest stands, together with environmental factors recorded in the field or derived from interpolated climatic data was collected. Using the hierarchical ISOPAM method, the relevés were classified into main forest types and their species composition, diversity and distribution were described. Their differentiation along main environmental gradients was analysed with classification and regression trees.ResultsEleven vegetation types of forests were distinguished and assigned to five vegetation classes: Quercetea mongolicae (representing the core of the Korean temperate forests), Vaccinio‐Piceetea (subalpine coniferous forest), Fagetea crenatae (rare beech‐dominated forest included within a sub‐montane and sub‐oceanic type of oak‐dominated forest), Querco mongolicae‐Betuletea davuricae (sub‐continental drought‐ and fire‐tolerant forest, differentiated along elevational gradient) and Camellietea japonicae (oceanic evergreen forest). At a higher hierarchical level, these 11 vegetation types were grouped into three clusters, which most probably reflect different vegetation development in the Late Pleistocene and Holocene. Within the three major vegetation clusters, each forest type occupies a distinct environment. The forest types are especially well separated along elevational and temperature gradients. The distribution of individual forest types is joinly driven by total amount of incoming energy and thermal extremes, both affecting water supply to plant communities.ConclusionsAll distinguished vegetation types can be assigned to the recent syntaxonomic classification system. However, three main vegetation clusters do not correspond to traditionally distinguished syntaxonomic units. Nevertheless, the forest types within these clusters share common species with similar ecology and, especially, migration histories during the late glacial and post‐glacial periods. Therefore, we interpret these clusters as biogeographic patterns reflecting vegetation history rather than the current environmental conditions.

Epiphytic lichen conservation in the Italian Alps: the role of forest type

Epiphytic lichens are a functionally important and species-rich component of Alpine forests, including several species of conservation concern. Their dependence on specific host trees predicts that forests with different tree species composition host different lichen communities, enhancing lichen diversity in forest landscapes. In this study, we tested for the first time the effect of forest type on patterns of epiphytic lichen diversity, in the Italian Alps. We sampled the main forest types of the South Tyrol, a typical Alpine region of Italy. We also assessed the influence of factors related to forest structure and climatic conditions. Our results demonstrate that different forest types host statistically different lichen communities, suggesting that the conservation of lichen diversity is entrusted to the maintenance of forest landscape heterogeneity, including forest types of minor economic value and rural habitats. The highest number of species was found in grazed larch forests and in high-elevation spruce forests, while the poorest pool was found in low-elevation spruce forests, beech forests and Scots pine ( Pinus sylvestris ) forests. High-elevation spruce forests also had the highest number of red-listed lichens, as the non-intensive management of these forest type allows the establishment of a rich lichen biota. Our results also emphasize the role for lichen conservation of some forest types that are of minor economic importance, such as oak ( Quercus pubescens ), riparian, and silver-fir ( Abies alba ) forests. This can also apply to grazed larch ( Larix decidua ) forests that are maintained by traditional farming, which shape one of the most pleasing aspects of the Italian Alpine landscapes. • Does forest type predict epiphytic lichen diversity in the Italian Alps? • We studied epiphytic lichen communities in the main forest types of the Italian Alps. • Significant differences in species composition and richness were found among forest types. • Conservation of lichen diversity is linked to the maintenance of forest landscape heterogeneity. • Forest with low-economic value highlighted also a key role on lichen conservation.

Land snail diversity and composition in relation to ecological variations in Central European floodplain forests and their history

We explored patterns of land snail assemblages using 93 alluvial forest sites in six river floodplains of the Elbe drainage basin (northwestern Bohemia, Czech Republic). Differences in species richness and composition across the four floodplain forest types (i.e., alder carrs, ash-alder forests, willow-poplar softwood forests, and hardwood forests) were analysed using generalized linear models, multidimensional scaling and redundancy analysis with the Monte Carlo permutation test. The studied floodplain forest types did not differ in species richness, except for the alder carrs which were significantly poorer. The number of species expressed a significant unimodal response along with elevation and Ellenberg nutrients, and further significantly decreased towards the most humid sites. Contrary to species richness, the main forest types clearly differed based on land snail species composition, with the exception of the ash-alder and willow-poplar forest sites which became completely overlapped in the ordination space. The main changes in species composition were mostly associated with elevation and Ellenberg moisture on the first MDS axis: Ellenberg nutrients and light were fitted on the second and the third axes, respectively. These variables, along with calcium content estimated using Ellenberg indicator values for soil reaction, had significant effects on the variation and snail species composition in the final RDA model. No response of either species richness or compositional changes was found for the measured content of topsoil calcium, most likely due to the higher importance of other variables. On the basis of some recently published data we can conclude that historical development and long-term human activities on the succession of floodplain assemblages have resulted in a sharp impoverishment of strictly land snail species of several hardwood forest sites in the majority of lower river stretches. Whilst in most areas there are no exact palaeoecological data available, these historical influences were closely correlated with the site elevation in our dataset as the main difference in species composition was hard to explain solely using environmental predictors.

Distribution and eco-coenotic patterns of the forest orchid Epipactis pontica in Slovakia

The present study is aimed at characterising the ecological niche of a typical forest orchid ( Epipactis pontica ) in Slovakia. Vegetation-environmental data were collected across mountain ranges and their foothills in the Western Carpathians in 2011. Numerical classification was performed to delimit the main forest vegetation types and a linear mixed effect model was applied to reveal differences between plots with versus without E. pontica . This endangered species of Slovak flora grows in thermophilous turkey oak forests ( Quercion confertae-cerris ), mesophilous broad-leaved mixed oak-hornbeam forests ( Carpinion betuli ), but most stands correspond to the acidic ( Luzulo-Fagion sylvaticae ) and mesotrophic beech forests ( Fagion sylvaticae ). Principal component analysis supported the floristic separation of plant communities and showed some significant vegetation environmental relationships. E. pontica prefers forests with closed canopy (mean canopy openness: 8.5–15.1%) occurring especially on slightly acidic (soil reaction: 4.48–5.65) and nutrient-poor soils (soil conductivity: 43.1–72.6 μS/cm). The proposed Ellenberg indicator values for light (4), temperature (5), continentality (4), moisture (5), soil reaction (6) and nutrients (5) follow species composition pattern of vascular plants in Slovak phytosociological relevés with E. pontica occurrence. They are also in accordance with its habitat conditions and ecological requirements in other parts of its range. The linear mixed effect model did not confirm any environmental peculiarity of plots with the presence of E. pontica at a microscale level and this result was consistent across the studied sites.

Response strategies of the main forest types to climatic anomalies across Croatian biogeographic regions inferred from FAPAR remote sensing data

Croatia is positioned in the transitional zone of South-eastern Europe and the Mediterranean, a region with frequent occurrence of severe droughts and dry spells, which makes it particularly vulnerable to the impact of climate change. It distends across three main European biogeographical regions – Continental, Alpine and Mediterranean – and therefore has a very high level of forest diversity comprised of 11 out of 14 European forest types. This makes it very convenient to study the exposure of main European forest types to extreme climatic events in the southern limits of their species distribution range. This study provides an assessment of responses of forest vegetation under episodes of climatic anomalies consisting of the most severe historical dry and warm spells in 2000 and 2003, together with the extremely rainy season in 2005 across Croatian territory. The question of interest in this study was to reveal how the existing forest types across the territorial gradient respond to highly expressed extreme climatic variations and to infer some clues about related adaptive strategies. The regional scale approach was applied which previously performed structural delineation of forest cover into eleven main forest groups or bioclimates and were examined considering functional differences. Responses of eleven bioclimatic types were analyzed by time series (1998–2005) of monthly FAPAR (The Fraction of Absorbed Photosynthetic Active Radiation) coverage with a spatial resolution of 1.2km, freely available from JRC FAPAR project. To quantify and differentiate the vegetation response in the considered years we adopted indices of resilience (resistance, recovery, resilience and relative resilience). We also provided a modified approach by applying these indices on a seasonal scale to examine the relationship between variations of phenology and ecosystem responses. The results confirmed the modification of seasonality of photosynthetic activity in relation to the altitudinal and spatial gradient. At the intra-seasonal scale, we distinguished specific opportunistic behavior of the common beech and oak forest types to alternating climatic conditions. Beech forest types show a very high ability to shift their phenology to earlier spring warming as a consequence of global warming. However, continental and Mediterranean oak forest types and in particular Aleppo pine and holm oak forests showed a higher increase of FAPAR during rainy events. The revealed capability of some tree species to better exploit rainfall in very wet periodic episodes has to be further evaluated in drawing conclusions about the overall resilience of forests under future climate change scenarios.

Ignition probability of fine dead surface fuels of native Patagonian forests or Argentina

Aim of study: The Canadian Forest Fire Weather Index (FWI) is being implemented all over the world. This index is being adapted to the Argentinean ecosystems since the year 2000. With the objective of calibrating the Fine Fuel Moisture Code (FFMC) of the FWI system to Patagonian forests, we studied the relationship between ignition probability and fine dead surface fuel moisture content (MC) as an indicator of potential fire ignition.Area of study: The study area is located in northwestern Patagonia, Argentina, and comprised two main forest types (cypress and ñire) grown under a Mediterranean climate, with a dry summer and precipitations during winter and autumn (~500-800 mm per year).Material and Methods: We conducted lab ignition tests fires to determine the threshold of fine dead fuel ignition at different MC levels. Moisture content of dead fine surface fuels in the field was measured every 10-15 days from November to March for three seasons. We calculated the FFMC during these seasons and correlated it with the measured MC by applying a logistic regression model. We combined the results of the ignition tests and of the regressions to suggest FFMC categories for estimating fire danger in Patagonian forests.Main results: The ignition threshold occurred at MC values of 21.5 and 25.0% for cypress and ñire sites, respectively. The MC measured varied from 7.3 to 129.6%, and the calculated FFMC varied between 13.4 and 92.6. Highly significant regressions resulted when FFMC was related to MC. The ignition threshold corresponded to a FFMC=85. We proposed to divide the FFMC scale in three fire danger categories: Low (FFMC≤85), High (85&lt;FFMC≤89) and Extreme (FFMC&gt;89).Research highlights: Our results provide a useful tool for predicting fire danger in these ecosystems, and are a contribution to the development of the Argentinean Fire Danger Rating and a reference for similar studies in other countries where the FWI is being implemented.Keywords: Austrocedrus chilensi; Nothofagus antarctica; wildfire; fire behavior; fuel moisture; fire weather index.

Stability of a Neotropical microrefugium during climatic instability

AbstractAimThe primary objectives of this study were (1) to assess, in the light of palaeoecological reconstruction, the climate stability hypothesis used by evolutionary biologists to explain high diversity in historically stable areas, and (2) to identify the response mechanisms of a tropical rain forest microrefugium to climatic variability.LocationNorth‐eastern Brazil, Serra de Maranguape.MethodsVegetation and climatic changes were reconstructed using a pollen record in a sediment core from a forest hollow, and the chronology was based on accelerator mass spectrometry radiocarbon analyses.ResultsPast vegetation dynamics consisted of three main forest types, shown by major compositional changes in rain forest assemblages between 5000 and 1000 cal. yr bp. Dense ombrophilous forest was abruptly replaced by heliophilous early successional tree taxa at 4275 cal. yr bp. These early successional tree taxa were established over a period of c. 100 years, and their dominance lasted for c. 750 years and was associated with dry conditions until 3525 cal. yr bp. Subsequently, the expansion of secondary successional tree taxa over a period of c. 550 years enabled the recovery of ombrophilous forest.Main conclusionsThe vegetation changes in the Serra de Maranguape provide evidence for the high sensitivity of this rain forest microrefugium to climatic variability on a multidecadal to millennial time‐scale during the mid‐ to late Holocene. Despite the substantial compositional and climatic changes, this microrefugium apparently was continuously forested and responded to climatic instability by recruiting key species to its highly diverse stock. This evidence helps to address the joint concerns of evolutionary biologists and palaeoecologists regarding how forests can persist during periods of climatic variability by showing that some tropical regions can remain continuously forested despite reorganization during abrupt and short‐term climatic changes.

秦岭火地塘林区油松和华山松林乔木层净生产力与气候因子的关系

以秦岭火地塘林区油松(<em>Pinus tabulaeformis</em>)和华山松(<em>Pinus armandi</em>)林为研究对象,以其生物量及树高-胸径模型为基础,运用树木年轮宽度方法推算出1973年至2011年生物量和生产力年际动态,并通过相关分析和多元逐步回归分析探讨了油松和华山松林乔木层净生产力与温度、降水之间的关系.结果显示,该林区油松林和华山松林乔木层生物量39a间增长迅速,分别从1973年的15.32 t/hm²和7.53 t/hm²增长到2011年的175.97 t/hm²和130.98 t/hm²,平均年净生产力分别为4.18 t hm^-2 a^-1和3.20 t hm^-2 a^-1,油松林乔木层生物量和生产力均高于华山松林;气候分析表明年净生产力与降水关系不明显,与温度关系较为密切,随气温升高呈波动上升趋势:单月气候因子中上年7月温度、当年7月温度与油松林乔木层净生产力显著正相关,上年7月温度与华山松林乔木层净生产力显著正相关;油松林乔木层净生产力动态变化主要受1-7月平均温度影响,华山松林主要受5-7月平均温度影响;油松林生产力与温度因子的相关性高于华山松林.两种林型的生物量和生产力差异是由油松和华山松生物学特性所致.;The Qinling Mountains have some of the best sites for research on impact of climate change on forest growth in China. We selected two main forest types in the mountains, <em>Pinus tabulaeformis</em> and <em>Pinus armandi</em> forests, to explore relationships between net primary productivity (NPP) of the tree layer and climatic factors in order to understand response of the growth to climate change. Nine plots of <em>P. tabulaeformis</em> and fifteen plots of <em>P. armandi</em> forests were established at the Huoditang forest region in the Qinling Mountains. More than 20 cross increment cores were extracted from different trees at each plot. After being cross dated by the skeleton diagram method, tree ring widths of increment cores were measured with WINDENDRO tree ring system. Annual diameters of sample trees were calculated using tree ring widths. Regression equations between diameter at breast height (DBH) and height of <em>P. tabulaeformis</em> and <em>P. armandi</em> forests at the Huoditang forest region were used to estimate the annual biomass and NPP from 1973 to 2011. Then correlations were analyzed between NPP and climatic factors including monthly and seasonal temperature and precipitation. Multiple stepwise regression analysis was used to select the climatic factors with the most impact on the annual NPP of the two forest types. A relatively consistent dynamic trend was found in the biomass and NPP of the two stands. The biomass of <em>P. tabulaeformis</em> and <em>P. armandi</em> forests increased dramatically in the past 39 years from 15.32 t/hm² and 7.53 t/hm² to 175.97 t/hm² and 130.98 t/hm², respectively, and the mean annual NPP were 4.18 t hm^-2 a^-1 and 3.20 t hm^-2 a^-1 respectively. Higher biomass and NPP of the tree layers were found in<em> P. tabulaeformis </em>compared to <em>P. armandi</em> forests. No significant correlation was observed between the NPP and monthly and seasonal precipitation; in contrast the NPP was closely correlated with the monthly and seasonal temperature. Among the monthly temperature factors, the temperature in July of the previous year correlated positively with NPP for <em>P. tabulaeformis</em> and <em>P. armandi </em>forests. Also the temperature in the current July correlated with NPP in the same year in <em>P. tabulaeformis</em> forests. Among the seasonal temperature factors, a significant coefficient was observed between the NPP of <em>P. tabulaeformis</em> forests and the mean temperature from January to July. A significant coefficient was observed between the NPP of <em>P. armandi</em> forests and the mean temperature from May to July; higher coefficients were found between the NPP of and climatic factors in <em>P. tabulaeformis</em> forests than that in <em>P. armandi</em> ones. The difference in the biomass and productivity between two kinds of forest types are due to their different biological characteristics.

湘中丘陵区南酸枣阔叶林群落特征及群落更新

Broad-leaved forest community dominated by Choerospondias axillaries is one of the main forest community types in the hilly area of central Hunan province,which plays a very important role in forest succession processes in subtropical region. In this study,a large permanent plot with an area of 1 hectares was established in the typical forest community of C.axillaries at the Dashanchong forest farm,Changsha county in the hilly region. The large plot was divided into 100 smaller sample plots of 100 square meters( 10m×10m). The characteristics of the C. axillaries community were investigated in detail to analyze biodiversity and regeneration dynamics of the community. In order to investigate the plant diversity of shrub and herb in the smaller plots,16 small samples were set up and distributed evenly in the sample plots,each small sample with area of 2m×2m. Plant diversity and succession dynamics were analyzed based on these field data. The results showed:( 1) in the arborous layer,there were 59 species in total which were more than 1 cm in diameter at breast height( DBH),belonging to 25 families and 42 genera in the community;( 2) the dominant species is C. axillaries with the largest important value( IV) of 23. 57 in the community. It was characterized with normal distribution in tree heights and DBH for the tree species of C. axillaries,with only 6 saplings of 1. 0cm to 1. 5 cm in DBH.( 3) The IV was 10. 46 for Symplocos setchuensis,7. 98 for Eurya muricata,5. 39 for Vernicia montana,and 4. 17 for Litsea coreana,respectively. The ratio of saplings,with less than 1. 5 cm in DBH,varied with different tree species,which was 22. 0% of saplings for the S.setchuensis population,16. 8% for E. muricata,11. 7% for A. montana,and 11. 0% L. coreana,respectively. The diameter structures of the 4 tree species showed an inverted J curve type.( 4) Considering the stratified structure of forest stands,the overstory were mainly occupied by C. axillaries,the understorey by S. setchuensis,E. muricata,V. montana and L. coreana.( 5) Forest seedlings were mainly dominated by evergreen broad-leaved tree species which regenerated well,with exception of C. axillaries saplings. These results indicated that the advantage of C. axillaries in the community was diminishing,whileas the importance of S. setchuensis,E. muricata,V. montana and L. coreana was increasing. Those evergreen broad-leaved tree species should be the dominate species in next succession stages,suggesting the C. axillaries broad-leaved community in hilly region of central Hunan province was developing toward the evergreen broad-leaved forest community succession.( 6) There were a total of 37 species in shrub and herb layer. The species with the largest five important values are Oropetalum chinensis,Rhododendron mariesii,Vaccinium bracteatum,Gardenia jasminoides and Rhododendron simsii,with an IV of 54. 59,21. 85,4. 98,4. 63 and 4. 53,respectively. The Loropetalum chinensis and Rhododendron mariesii were both dominant species in the shrub layer.

我国东北天然林保护工程区森林植被碳储量研究

以东北天然林保护工程区森林生态系统为对象，通过对其主要森林类型进行调查，探讨天保工程经营区划对森林植被固碳现状的影响，并结合已有的东北林区生物量与蓄积量数据库，建立了东北林区主要树种组的生物量-蓄积量回归模型，然后以第7次森林资源清查为基础，对东北天保工程区森林植被碳储量进行估算，以期为全国森林生物量的估算和天保工程的评估提供参考。结果表明，不同经营区之间（重点公益林、一般公益林和商品林）森林植被碳密度的差异并不显著，这可能与天然林保护工程实施初期经营区划的标准、样地的选择以及天保工程实施过程中粗放的管理方式有关。东北天保工程区森林植被碳储量为1045 TgC，占东北、内蒙古三省森林植被总碳储量的68%；工程区以天然林为主，占工程区总植被碳储量的97%。工程区森林植被平均碳密度为41 Mg/hm²，较东北、内蒙古三省平均植被碳密度高14%；工程区植被碳密度随林龄的增加逐渐增大，由幼龄林的13 Mg/hm²到过熟林的63 Mg/hm²。因此，继续加强天然林保护工程的实施，提高其林分质量，这对未来我国森林碳汇潜力的增加和森林的可持续发展都具有重要的意义。;The Natural Forest Protection Program (NFPP), which aims at protecting ecological resources and achieving sustainable forest management, has been implemented for 10 years in Northeast China. Under the program forest ecosystems in the region have been divided into three management areas-Key conservation, General conservation and Commercial forest. Each of these three types of forest land is subject to different management measures (protecting or logging). Estimating carbon storage of forest vegetation in these areas is important both for understanding the capacity of forests in the Northeast region for carbon sequestration and as an aid to assessing the effectiveness of the NFPP in meeting its goals. To address this important need, this study selected five major forest types in the Northeast forest region-larch forest, birch forest, coniferous mixed forest, broadleaved mixed forest, coniferous and broadleaved mixed forest. Each forest type was divided into four age classes-young, mid-aged, premature and over mature forest. Tree biomass was calculated through species-specific allometric equation models based on field measurement in the Daxing'anling, Xiaoxing'anling and Changbai mountains. At the same time, an dataset on biomass and volume of the main forest types in the Northeast forest region was established based on existing data from former studies. Since some studies have found that the relationship between forest biomass and volume fits relatively well within a liner regression framework, this study utilized this two data sources noted above to establish biomass-volume line regression models of the main tree species groups in the Northeast, focusing primarily on the five major forest types identified above. Forest biomass carbon storage in areas under the NFPP in the Northeast region was subsequently estimated based on data from the 7th National Forest Resource Inventory. Results showed that forest biomass carbon storage based on field measurement did not varied significantly with management areas, which likely reflects both the classification standard for the management areas and the relatively short period since the NFPP have been implemented. On the other hand, forest biomass carbon storage of lands under the NFPP was 1045 TgC, which accounted for 68% of total forest biomass carbon storage in the Northeast provinces of Jilin, Heilongjiang and Inner Mongolia. Moreover, forest biomass carbon density of lands under the program (41 Mg/hm²) exceeded that of the average biomass carbon density in Northeast provinces (36 Mg/hm²). Simultaneously, in the lands of the NFPP, forest biomass C density increased with forest age class, from 16.4 Mg/hm² in young to 63.0 Mg/hm² in over mature forest, thus the relative large areas of young and mid-aged forests (together accounted for 61% of total forest area), implying its great C sequestration potential in the future. In addition, forest biomass carbon storage was dominated by natural forest, which accounted for 97% of total biomass carbon storage under the NFPP. On an overall basis, the Natural Forest Protection Program acts an important role in the Northeast forest region, and it should be played an increasingly important role in forest ecosystem carbon sequestration and sustainable forest management in the next implemented decade.

Carbon Stock Calculating and Forest Change Assessment Toward REDD+ Activities for The Mangrove Forest in Vietnam

Mangrove forests are one of the main forest types in Vietnam. However, during the last decades, a lot of mangrove forest area has been converted to other land-use types. The objectives of this study are to assess the changes that occurred in the mangrove forests from 1990 to 2010 and to determine a method for carbon-stock calculating for the forests that can be used as the input data for a Reference Emission Levels (REL) calculation. The study was conducted in two different research areas; one was the Quang Ninh province in the north of Vietnam, and the other took place in the Ca Mau and Kien Giang provinces in the south. In this research, the maps of mangrove forests for the periods of 1990, 2000, and 2010 were created by using optical satellite-imagery data. The change matrix was then calculated by overlaying maps of different periods in the forests for analyzing the changes and assessment. Field trips were also taken to each study area in order to verify/adjust the latest classified mangrove forest maps and interview/identify the main causes of land-use changes taking place during these periods. During the fieldwork, a number of sample points were surveyed to collect the number of parameters of mangrove trees. These data are then used for analyzing the relationship between tree height and the HH and HV values of ALOS PALSAR (Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar) data. An allometric relationship between biomass and tree height was also applied for investigating the relationship between aboveground biomass and ALOS PALSAR polarimetric data. Finally, the change in the carbon stock of the forests through all periods was estimated for living biomass, fuel-wood gathering, and other losses by applying the stock-change method. The results of this study were the mangrove forest maps and biomass maps for the years 1990, 2000, and 2010; the changes analysis showed that the forest area is decreasing and that the main cause is the conversion of the forests to aquaculture land, according to the equations/models of biomass estimation for biomass mapping based on ALOS PALSAR data.

Relationships between diameter and height of trees in natural tropical forest in Tanzania

The relationship between tree height (h) and tree diameter at breast height (dbh) is an important element describing forest stands. In addition, h often is a required variable in volume and biomass models. Measurements of h are, however, more time consuming compared to those of dbh, and visual obstructions, rounded crown forms, leaning trees and terrain slopes represent additional error sources for h measurements. The aim of this study was therefore to develop h–dbh relationship models for natural tropical forest in Tanzania. Both general forest type specific models and models for tree species groups were developed. A comprehensive data set with 2 623 trees from 410 different tree species collected from a total of 1 191 plots and 38 sites covering the four main forest types of miombo woodland, acacia savanna, montane forest and lowland forests was applied. Tree species groups were constructed by using a k-means clustering procedure based on the h–dbh allometry, and a number of different non-linear model forms were tested. When considering the complexity of natural tropical forests in general and in particular variations of h–dbh relationships due to high species diversity in such forests, the model fit and performance were considered to be appropriate. Results also indicate that tree species group models perform better than forest type models. Despite the fact that the residual errors level associated with the models were relatively high, the models are still considered to be applicable for large parts of Tanzanian forests with an appropriate level of reliability.

Solos e geoambientes do Parque Nacional do Viruá e entorno, Roraima: visão integrada da paisagem e serviço ambiental

http://dx.doi.org/10.5902/198050989287O Parque Nacional (PARNA) do Viruá ocupa 227.011 ha, na região do baixo Rio Branco, Roraima. A região compreende um extenso mosaico de ambientes complexos inundáveis, florestais e não florestais. Este trabalho teve como objetivo geral detalhar os aspectos pedológicos e geoambientais do Parque e entorno, em uma visão integrada da paisagem e, além disso, estimar o estoque de carbono nos solos e geoambientes. Foram descritos e coletados 29 perfis de solos nas principais fitofisionomias de Campinaranas e Florestas do Parque e entorno. Destacaram-se os seguintes: Espodossolo Humilúvico, Neossolo Quartzarênico, Neossolo Flúvico, Neossolo Litólicos, Latossolo Vermelho-Amarelo, Latossolo Vermelho, Cambissolo Háplico, Cambissolo Flúvico, Gleissolo Háplico e Plintossolo Háplico. Os solos apresentaram distribuição espacial com limites abruptos e com forte associação entre as fitofisionomias. Foram agrupados em três pedoambientes: (1) solos arenosos das campinaranas, (2) solos associados aos inselbergs e adjacências e (3) solos aluviais. Foram mapeadas e descritas 18 unidades geoambientais no Parque e entorno. Os geoambientes predominantes no Parque foram: Planícies Arenosas e Paleodunas com Campinarana Graminosa e Arbustiva em Neossolos Quartzarênicos hidromórficos e Espodossolos; e Planícies de Inundação e Terraços com Floresta de Igapó sobre solos hidromórficos arenosos, com respectivamente 24,6 % e 20,1 % da área estudada. Em termos de estoque total de carbono nos solos, destacaram-se os geoambientes dos complexos arenosos das Campinaranas e associações, com 9450,9 Gg C. A grande extensão e representatividade dos complexos arenosos das Campinaranas fazem do PARNA Viruá uma Unidade de Conservação de proteção integral com forte vocação para preservação e conservação de sistemas arenícolas amazônicos. As áreas sob o domínio de Espodossolos possuem os maiores estoques de carbono orgânico e os complexos arenosos das Campinaranas e associações representam os geoambientes mais relevantes na prestação de serviços ambientais de conservação do carbono nos solos.

Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains

Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features.