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1.
Effects of selection cutting on the forest structure and species diversity of evergreen broa-leaved forest in northern Fujian, southern China 总被引:2,自引:0,他引:2
Qiu Ren-hui Chen Han Zhuo Li-xin 《中国林学(英文版)》2006,8(1):16-20
The short-term effects of selection cutting of different intensities on the forest structure and species diversity of evergreen broad-leaved forest in northern Fujian Province were investigated and analyzed. The results showed that selection cutting of low and medium intensities caused little variation in the forest structure. After cutting, the dominant species retained their leading status in the community. However, the community structure changed significantly following selection cutting of high and extra-high intensities; the status of the dominant species of the community declined dramatically. Some tree species began to disappear from the sampling plots. Except for extra-high intensity cutting, the diversity of tree species did not change significantly for the other three cutting intensities. However, the evenness of the stands was very different among the four kinds of cutting plots. For low and medium intensity selection cutting, the evenness declined slightly. For extra-high intensity selection cutting, the evenness increased to some extent, which might be due to a more even distribution of tree species after cutting. Cutting operations resulted in some adverse reactions to development of arborous species diversity of evergreen broad-leaved forest, particularly serious damage to the forest canopy. But the rational selection cuttings, which may benefit the restoration and maintenance of species diversity over a long period and may come about from the variations in environmental factors such as sunlight, temperature and humidity. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):140-148
Abstract This study describes forest landscape fragmentation and connectivity along the Finnish–Russian border near the Karelian Isthmus. The landscape pattern was analysed using classification data based on Landsat ETM+ and Landsat TM images in combination with systematic surveys in Finland (Finnish National Forest Inventory) (n=546) and the authors’ own fieldwork data in Russia (n=101). On the Finnish side the forest patches are significantly smaller than on the Russian side. In addition, the Finnish forests landscape is more scattered and distances between patches of the same forest type are longer. The Russian side is more dominated by broadleaved and mixed forest stands. The disparities are due to differences in forestry policy and traditions of forest practices. The growing conditions of the areas are similar. The habitat fragmentation and habitat connectivity are important issues because the Karelian Isthmus is one of three main corridors and migrating routes connecting large Russian boreal taiga forests and their fauna and flora with Finnish isolated boreal forests. 相似文献
3.
Comparative regeneration status in a natural forest and enrichment plantations of Chittagong (south) forest division, Bangladesh 总被引:2,自引:0,他引:2
于2002年4月至11月,对孟加拉Chittagong (南部)林区天然纯林和肥沃地人工林树种更新情况进行了比较研究。共设100个3m×3m的样地(天然林50个,人工林50个)。共记录天然林更新树种64个,苗木密度为24767株/hm2;人工林更新树种40个,苗木密度为18633株/hm2。天然林更新量最大的树种为Castanopsis spp.(2200 株/hm2),其次是Glochidion lanceolarium (2183 株/hm2);人工林更新量最大的树种为Dipterocarpus gracilis (2117株/hm2),其次是Anogeissus acuminata (2000株/hm2)。对天然林而言, Castanopsis spp 的相对密度最高(8.88%), Glochidion lanceolarium 的相对频度最高(7.36%),Syzygium spp. 的相对富有度最高(3.79%),Glochidion lanceolarium的重要值指数最高(18.24%);对人工林而言,Dipterocarpus gracilis的相对密度最高(11.36%),Glochidion lanceolarium的相对频度最高 (9.71%), Dipterocarpus gracilis的相对富有度最高(5.92%), Glochidion lanceolarium的重要值指数最高 (23.32%)。Dipterocarpus gracilis 常见种在天然林和人工林都有更新苗木,但人工林的苗木要高于天然林。天然更新的苗木非常密集,但由于人为的干扰,这些更新的苗木通常达不到径干生长期。表4参35。 相似文献
4.
Guangyu Wang Shari L.Mang Brianne Riehl Jieying Huang Guibin Wang Lianzhen Xu Kebiao Huang John Innes 《林业研究》2019,(1):277-293
Expert opinions have been used in a variety of fields to identify relevant issues and courses of action. This study surveys experts in forestry and climate change from the Asia–Pacific region to gauge their perspectives on the impacts of climate change and on the challenges faced by forest adaptation in the region, and explores recommendations and initiatives for adapting forests to climate change. There was consensus regarding the impacts of climate change on forest ecosystems and on economic sectors such as agriculture and forestry. Respondents also indicated a lack of public awareness and policy and legislation as challenges to addressing climate change. However, the results indicate differences in opinion between regions on the negative impacts of climate change and in satisfaction with actions taken to address climate change,highlighting the need for locally specific policies and research. The study presents specific recommendations to address issues of most concern, based on subregion and professional affiliation throughout the Asia–Pacific region.The results can be used to improve policy and forest management throughout the region. This research will also provide valuable suggestions on how to apply research findings and management recommendations outside of the AP region. The conclusions should be communicated relative to the level of the research and the target audience,ensuring that scientific findings and management recommendations are effectively communicated to ensure successful implementation of forest adaptation strategies. 相似文献
5.
We investigated the correlation of large fires([300 ha) from 1992 to 2013 within the borders of the Antalya Regional Directorate of Forestry using the Keetch–Byram drought index(KBDI). Daily KBDI values were calculated for each year, and values for the period before the year 2000 differed significantly from those after2000. After 2000(large fires occurred in 2004, 2006, 2007,2008, 2010, and 2013), when KBDI values increased, the KBDI, but not the number of fires, was inversely correlated with the natural log of the burned area(NLBA). While there were both high and low KBDI values when the NLBA was small, only high KBDI values were associated with high NLBA values. Particularly for logarithmic values of 4 and higher, KBDI values increased in parallel with increases in NLBA values. On the basis of a Mann–Whitney U test done in addition to a Pearson correlation test, we found that when the burned areas were grouped according to small and large areas, the KBDI could be used to distinguish the two groups. Using a conditional probability analysis, we found that 4th, 5th and 6th class KBDI values may lead to large fires at the 60 % possibility.Similarly, the possibility of large fires greater than the median burned area in any given 6 years was found to be48 %. In addition, while the mean value of KBDI is 390.51 for the period from May to September for these 6 years, it is 359.93 for the other years. Consequently, the area burned also increased as the KBDI classes(Class 0: 0–99, Class 1:100–199, Class 2: 200–299, Class 3: 300–399, Class 4:400–499, Class 5: 500–599, Class 6: 600–699, and Class 7:700–800) increase. 相似文献
6.
Elias Milios Elias Pipinis Kyriaki Kitikidou Maria Batziou Stelios Chatzakis Sofia Akritidou 《New Forests》2014,45(2):165-177
The present study was conducted in a lowland degraded Quercus remnant forest in northeastern Greece. In 2006, ten plots of 50 m × 50 m were randomly selected in two site types. Site type A is covered by Quercus pubescens–Quercus frainetto stands that are under grazing pressure. In Site type B there are Q. pubescens stands and grazing pressure is more intense. Inside these plots 180 subplots of 2 m × 2 m were established in three regeneration environments and the number of sprouts and seedlings was counted. The three regeneration environments were: (a) rather dense groups of trees, (b) areas with bare soil that alternate with areas with grazed herbs and (c) areas covered only from sparse scattered trees. Moreover the regeneration plants were classed as recently grazed and not recently grazed plants. Six years later, 180 regeneration plants having a height equal to or over 20 cm were selected and were classed as seedlings or sprouts. Sprouts were the dominant form in regeneration. The sprouting ability of Q. pubescens and Q. frainetto seems to be an adaption that enables them to endure grazing. Grazing was the main factor that determined the distribution of regeneration. The ecological differences of the two species do not seem to substantially influence their distribution in the different regeneration environments. It seems that intense grazing keeps the regeneration plants in low height. However, regeneration density can be considered adequate for the perpetuation of the studied stands if the grazing stops. 相似文献
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In 2013, we re-inventoried all lianas(C1 cm diameter measured at 1.3 m from the rooting point) in four1-ha permanent plots distributed one each in four sites of inland tropical dry evergreen forest on the Coromandel Coast(Pudukottai district) of peninsular India, established in 2003. Among the four sites, Shanmuganathapuram(SP)and Araiyapatti(AP) were much disturbed and the other two sites(Karisakkadu—KR and Maramadakki—MM)were moderately disturbed. We inventoried a total of 3425 lianas representing 37 species of 33 genera and 22 families.Over a decade(2003–2013) liana species richness increased at two sites(MM and SP) and no changes occurred at the other two sites. Liana abundance increased by 210, 211, 164 and 162 individuals at sites AP, KR, MM and SP, respectively, and basal area increased(from 1.09 to1.76 m2 at AP, 0.67 to 0.86 m2 at KR, 1.68 to 2.06 m2 at MM, and from 0.44 to 1.06 m2 at SP). Over a 10-year period, three species(Abrus precatorius, Canavalia virosa,and Cocculus hirsutus) were lost and five species(Gloriosa superba, Ampelocissus tomentosa, Capparis sepiaria,Aganosma cymosa and Tiliacora acuminata) were newly added. Total aboveground biomass increased by 18.5, 0.74,3.6 and 9.5 Mg ha-1, respectively, at sites AP, KR, MM and SP. 相似文献
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《Forest Ecology and Management》1998,106(1):9-18
Dendroecological techniques were used to examine the disturbance history and patterns of species recruitment in an old-growth Quercus rubra L. (northern red oak)–Acer saccharum Marsh. (sugar maple)–Tilia americana L. (basswood) forest on a steep, talus slope in eastern West Virginia. The forest was uneven-aged as were the populations of red oak. Sugar maple dominated the sapling layer, which comprised little or no basswood and red oak. A compilation of major and moderate releases (indicative of disturbance) in 25 cores revealed single or multiple release events in every decade from 1870–1990. The high elevation of the forest coupled with a fertile sub-soil beneath the talus ameliorated the outwardly harsh conditions of the site, allowing for the domination of typically mesophytic, nutrient demanding tree species. We observed several fire scarred trees as well as extensive small-scale blow-down throughout the forest. Frequent disturbance events were probably crucial to the co-existence and continuous canopy recruitment of the relatively light demanding red oak with highly shade tolerant sugar maple and basswood. The strong successional replacement tendencies of red oak by northern hardwoods noted elsewhere in the eastern US may be less apparent on high elevation, rocky sites in the central Appalachians. Thus, this is a unique case study of long-term red oak domination with later successional species in an old-growth forest. 相似文献
12.
Plants diversity and phenological pattern of the trees were monitored in a montane wet temperate forest (shola) in the 相似文献
13.
Diane Saint-Laurent Jean-Sébastien Berthelot Vernhar Gervais-Beaulac 《Agroforestry Systems》2018,92(6):1517-1534
A number of forests in agroforestry environments are at risk due to urban development or agricultural expansion. These forests often consist of patches of wooded areas scattered in the agricultural and urban grid, and often constitute green corridors that enable a flow between animal and plant species (migration corridors). This study evaluates the composition and structure of riparian forests in agroforestry areas that are subject to various natural and anthropogenic disturbances. This study aims to understand the dynamics of these riparian forest populations and evaluate the effects of the disturbances on the tree stands (e.g. floods, partial cutting), while taking into account their development over space and time based on a diachronic assessment from 1945 to 2010. Although these woodlands are subject to various disturbances, a fairly large diversity of tree species can be noted, and the regeneration of the saplings and small trees follows a normal growth curve (asymmetric) with a high contingency of young tree population comparable to a typical reverse-J distribution. However, lower densities are observed for riparian stands subject to frequent flooding, which could over time compromise recruitment and forest regeneration for some tree species (e.g. woody plants with weak adaptive strategies). The multivariate analyses (Redundancy Analysis and Canonical Correspondence Analysis) conducted over all the soil, environmental and forest data reveal that some variables are more strongly related to the composition of the forest populations, including pH, ground litter and soil drainage. However, these variables must still be considered as being part of a set of interacting soil conditions. Lastly, the future of these woodlands may appear uncertain because there are no government policies or measures to ensure their protection and preservation. 相似文献
14.
WUSihong ZHANGXiaoming ZHUQinke KeyLaboratory of Soiland Water Conservation Combating Desertification Ministry of Education College of Soil WaterConservation Beijing Forestry University Beijing China 《中国林业科技(英文版)》2006,5(2):54-65
INTRODUCTION The vegetation construction on the Loess Plateau is of significant importance in ameliorating the serious situation of soil and water conservation. The Loess Plateau is characterized by lots of gullies, and its surface soil is fragile and easily eroded, the factors that influence soil and water loss are: rainfall, vegetation, slope and others. Rainfall is the motive, power of causing soil and water loss; besides, vegetation and slope also greatly affect soil and water loss. … 相似文献
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Yacine Kouba Felipe Martínez-García Ángel de Frutos Concepción L. Alados 《European Journal of Forest Research》2014,133(6):1057-1072
An understanding of spatial patterns of plant species diversity and the factors that drive those patterns is critical for the development of appropriate biodiversity management in forest ecosystems. We studied the spatial organization of plant species in human-modified and managed oak forests (primarily, Quercus faginea) in the Central Pre-Pyrenees, Spain. To test whether plant community assemblages varied non-randomly across the spatial scales, we used multiplicative diversity partitioning based on a nested hierarchical design of three increasingly coarser spatial scales (transect, stand, region). To quantify the importance of the structural, spatial, and topographical characteristics of stands in patterning plant species assemblages and identify the determinants of plant diversity patterns, we used canonical ordination. We observed a high contribution of β-diversity to total γ-diversity and found β-diversity to be higher and α-diversity to be lower than expected by random distributions of individuals at different spatial scales. Results, however, partly depended on the weighting of rare and abundant species. Variables expressing the historical management intensities of the stand such as mean stand age, the abundance of the dominant tree species (Q. faginea), age structure of the stand, and stand size were the main factors that explained the compositional variation in plant communities. The results indicate that (1) the structural, spatial, and topographical characteristics of the forest stands have the greatest effect on diversity patterns, (2) forests in landscapes that have different land use histories are environmentally heterogeneous and, therefore, can experience high levels of compositional differentiation, even at local scales (e.g., within the same stand). Maintaining habitat heterogeneity at multiple spatial scales should be considered in the development of management plans for enhancing plant diversity and related functions in human-altered forests. 相似文献
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In July 1992 the Rondônia Agroforestry Pilot Project (RAPP) was launched in two agricultural municipalities (Nova União and Alto Paraiso) in the western Brazilian Amazon State of Rondônia. The purpose of the RAPP was to assess the conditions under which colonist farmers in the western Amazon would integrate agroforestry plantings into their small-scale farming systems and to assess the performance of those plantings over time. An experimental group consisting of 50 small-scale farmers was selected to participate. Plots were designed to accommodate between 3 and 25 different species, each producing one or more commodities with local market potential (hardwood, fruits, nuts, latexes, oils). Farmers planted seedlings typically on a 1-ha plot, located and designed by each farmer with the advice of a professional Brazilian extensionist. During the first phase of the project (1992–1998), the growth performance of the seedlings and changes in household characteristics were monitored on an annual basis. By 2002, 32 (64.0%) of the original 50 agroforest plots were found in place. This paper updates the research findings based on a 2002 follow-up visit to these 32 farms. In addition to growth performance, the authors’ found that 17.95% of the farms in the neighboring control group had planted trees and other agroforest crops between 1992 and 2002, compared to only 5.38% of farms outside the project area, suggesting spontaneous diffusion. The authors also found a potentially synergistic relationship between agroforestry and secondary forest regeneration with the use of satellite image analysis. The experience of the RAPP indicates that colonist farmers in Amazonia can be successful managers of agroforest plots with minimal external inputs over the long-term (10 years). 相似文献
17.
The contribution shows changes in the phosphorus and nitrogen status in long-term investigated spruce stands in the Lu?ické, the Jizerské and the Orlické Mts. on the border between the Czech Republic and Germany and Poland. During the 11 evaluated years, low phosphorus concentrations were measured, often below the deficiency limit 1.2 mg P/g, and an N/P ratio exceeding the optimal range (6–12), primarily in the second needle-year class. Values of an N/P ratio of between 12 and 18 in the Jizerské Mts. and of between 12 and 27 in the Lu?ické Mts. were discovered. A low phosphorus concentration below the 10 mg·kg?1 was also detected in the mineral soil horizon. Temporal changes of N/P ratio (increase) and of P concentration (decrease) in the needles are significant for the spruce stands that are in the Orlické Mts. In the Jizerské Mts. and the Lu?ické Mts., there is fluctuation during evaluated period without any clear trend. 相似文献
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Portugal's forests in the 12th century were dominated by the Fagaceae represented by Quercus and Castanea, and several pine species.From the 12th century onwards, forests underwent changes in their management starting with protection and ultimately leading to intense exploitation. The massive naval construction during the maritime expansion(mainly in the 15th–16th centuries) involved felling of approximately 5 million trees mainly Quercus suber, Pinus pinea and other Quercus species. Cumulative fuel-wood consumption of 959 Mm3 during 1300–1854 was attributed to demographic expansion while the deforestation rate during 1636–1854 accounted for a minimum of 72.6% and a maximum of 96% of total forest cover. The volume of timber used in railway sleepers from 1856 onwards might have reached 0.5 Mm3. The last quarter of the 20th century increased the forest cover of Portugal through the World Bank program of Eucalyptus globulus reforestation. 相似文献
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Forest structure changes continuously by natural and anthropogenic effects. Because the level of goods and services provided by forest ecosystems are related to this structure, some attributes have to be controlled while they are being managed. In this paper we describe the long-term temporal changes in land area and landscape metrics related to different land uses of a managed forest in Turkey. The study was carried out for the Daday Forest Planning Unit located in the west Black Sea region of northern Turkey. The total area is 16,813 ha and besides wood production, it is managed for erosion control, public health, aesthetics, and recreation. Stand type maps that were constructed in 1970, 1989, 1999, and 2010 were used in this analysis. Transition matrixes that illustrate area changes among cover types and temporal changes on some landscape metrics were obtained using Geographic Information Systems. Stands were separated into small patches, and thus the number of patches increased nearly two-fold between 1970 and 2010. The total forest edge increased and through the associated fragmentation, the amount of core forest area decreased at the landscape scale. Landscape metrics were applied to digitized versions of historical maps to assess how forest area changed. Human use of the land has changed, forest management practices have evolved, and these along with natural forest growth have contributed to interesting changes in landscape character. 相似文献
20.
Heterogeneity of forest stand structure often results from repeated small disturbances, but structural variation also arises in a stand that has regenerated after a single large stand-replacing disturbance. We explored the structural variation within a subalpine Abies forest in Japan that regenerated after a large typhoon in 1959. In 2004, four 50 × 50 m plots were established at two sites in the regenerated forest. To characterize local stand structure within each plot, we determined the stem density, stand basal area, mean diameter at breast height (DBH), and coefficient of variation (CV) of DBH in 10 × 10 m subplots. We analyzed the spatial distribution pattern of the trees in each subplot using the L(t) function and categorized the distributions as clumped or non-clumped. The analysis revealed marked variation among subplots in the stand’s structural characteristics. Although the spatial distribution patterns of the trees in all plots were clumped, 11 of 50 subplots at one site and 39 of 50 subplots at the other site were non-clumped. Subplots with a clumped distribution pattern generally had a smaller basal area, smaller mean DBH, and greater CV of DBH than subplots with the same density but a non-clumped pattern. These results illustrated the spatial heterogeneity of forest structure that can arise in Abies forest that has experienced a large disturbance, probably because of the different densities and distribution of saplings surviving the disturbance and the different forest growth dynamics that result. 相似文献