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1.
The aim of this study was to evaluate how future harvesting of spruce low stumps as a renewable energy source, might influence the saproxylic (wood living) beetle fauna. Species richness, abundance and assemblages of saproxylic beetles were compared on low stumps, high stumps and logs of spruce on 10 clear-cuts in northern Sweden. The sampling was conducted with emergence traps and a total of 929 individuals and 120 species were collected. No significant differences in beetle abundance or species richness were detected between substrate types. However, there were clear differences in assemblage composition between all substrate types. Our results suggest that low stumps created at final felling support as many species and individuals per volume dead wood as other dead wood substrates and that they are therefore overlooked as substrates for wood living organisms. Consequently, harvesting of low stumps might have negative effects on the diversity of saproxylic beetles, as up to 80% of the dead wood remaining on clear-cuts is in the form of low stumps. Future studies should evaluate if compensatory measures can be performed to minimize negative impacts.  相似文献   

2.
We have experimentally investigated the impact of biotic factors, acting at the seed and seedling stages, on a Quercus pyrenaica forest in the Sierra Nevada mountains (SE Spain). We monitored the natural establishment of the oak for 3 years in two forest plots and two shrubland plots, by counting seedlings and juveniles. In addition, we established several experiments in these plots to examine acorn and seedling survival, while also considering the microhabitat effect on survival probability. Dispersed acorns were quickly consumed by several species of predators, particularly wild boar (Sus scrofa) and woodmouse (Apodemus sylvaticus). Less than 4% of the experimental acorns survived to produce seedlings, even when they were buried 4 cm in soil, simulating caches. No effect of microhabitat was found on predation, and thus no safe site appears to exist for Q. pyrenaica acorns in the study area. Some 98% of the 1000 experimental seedlings were killed by herbivores, notably woodmice, wild boar, and domestic and wild ungulates. Seedling survival varied spatially, being significantly higher under shrubs (4%) than in any other microhabitat (less than 0.5%). Both acorn and seedling survival were much lower in the shrublands than in the forests. In shrubland plots, the main agent of seedling mortality was trampling by domestic ungulates foraging in herds. This study suggests that the regeneration of Q. pyrenaica forests in Mediterranean mountains can be limited by herbivores acting at several life-history stages.  相似文献   

3.
In the western Mediterranean region of Catalonia (NE Spain), during the last 20 years of the 20th century, the range of many forest bird species has expanded. Our objective was to characterize the roles of (a) spatial population processes (related to dispersal), (b) changes in forest structure (due to forest maturation and management), and (c) landscape composition (resulting from afforestation and fires) in the range expansion of these bird species at the landscape scale (10 × 10 km). After correcting for the differences in sampling effort, colonizations appeared to be more likely near areas in which the species had been present in the 1980s. Patterns of the range expansion were also strongly associated with forest maturation, which seems to affect the spatial arrangement of birds at multiple scales. Changes in forest landscape composition due to afforestation and fires were minor determinants of range changes, and forest management did not seem to prevent range expansion at the spatial scale studied. Colonization events appeared to be driven primarily by landscape changes occurring in nearby localities rather than within the colonized locations themselves, presumably because of source–sink dynamics and connectivity patterns. Our results showed that in Catalonia, at a landscape scale, the impact of forest management on forest bird communities is much smaller than the impact of the widespread maturation of forests following a large-scale decline in traditional uses.  相似文献   

4.
This study analyzes the sustainability of community forest management, representing four forest types of two physiographic region Hills and Terai of Nepal. We assess the sustainability based on species composition, stand density, growing stock volume, and growth-to-removal ratio using inventory data of 109 permanent forest plots from four consecutive intervals of three to five years. In addition, forest users, forest committee members, and forest officials were consulted. We observed increment on the representation of economically valuable tree species in all forest types of both regions. The pole-size tree dominates in all forest types with declining number of trees and regeneration. In case of Hills forests, they were over-harvested until 2013 but were under-harvested in the recent period. In contrary, forests were under-harvested in the Terai. We found that ecological objectives of sustainable management are fully achieved while economic benefits remained unharnessed where harvesting is far below the growth. We conclude that maintaining a large number of trees may contribute to ecological but not on economical sustainability. We argue to rationalize annual harvest in all categories of the forest to enhance resource conditions together with regular benefits to the local communities.  相似文献   

5.
Forest management activities potentially influence ecosystems at many spatial scales. For most forest systems, influences at the stand level have been most intensively studied and are best understood. Management impacts at the larger, landscape scale are poorly understood and many hypotheses regarding landscape-level effects remain untested. This lack of knowledge is particularly acute in bottomland hardwood forest (BLH) ecosystems. Most hypotheses regarding landscape-level impacts were derived from theories about island biogeography and metapopulations. Thus, species presence and productivity sometimes are viewed as functions of patch characteristics such as size, shape, amount of edge, degree of isolation from larger, similar habitats, time since isolation, and dispersal, immigration, and extinction rates. Recommendations for mitigating fragmentation effects often include maintenance of reserves, increasing patch size, reducing edges, and enhancing connectivity through the use of corridors. While many of these theories are intuitively sound, there are few data to demonstrate their effectiveness in landscapes dominated by managed forests, including BLH forests. We suggest that high priority be given to using adaptive management to simultaneously test hypotheses about how biotic communities function in managed, BLH landscapes. Such information would help managers understand the consequences of their activities, provide them with more flexibility, and improve their ability to protect biological diversity while also meeting society's needs for forest resources.  相似文献   

6.
Forest management practices which may represent various forms of disturbance regimes could influence liana species richness, abundance and relationship with their hosts. The study sought to determine the impacts of three management systems, namely, the Selection, Tropical Shelterwood and Post Exploitation Systems (SS, TSS and PES respectively) on liana species richness, abundance and relationship with trees in the Bobiri forest reserve, Ghana. Lianas with dbh ≥ 2 cm found on trees with dbh ≥ 10 cm were enumerated in 1 ha plot each in the SS, TSS and PES. All trees (dbh ≥ 10 cm) within the plots that did not carry lianas were also enumerated. A total of 640 liana individuals belonging to 27 species, 22 genera and 13 families were identified in the management systems. Griffonia simplicifolia (Vahl ex DC.) Baill., Motandra guineensis (Thonn.) A.DC. and Calycobolus africanus (G.Don) Heine were the abundant species in all the management systems. Unlike in SS, lianas in the TSS and PES were dominated by a few species. Larger diameter lianas were more abundant in the PES (32%) compared with the SS (18.3%) and the PES (13.1%). Liana diversity (H′) (species richness and abundance) was quantitatively higher in the SS (2.8) than the TSS (2.2) and the PES (2.0). The numbers of lianas carried by tree species differed significantly in the management systems (p < 0.001 each). Liana infestation in the forest was high. The level of liana infestation did not reflect the extent of liana load per tree in the management systems. Larger trees carried significantly more liana individuals than smaller trees in the PES (p = 0.019, r2 = 0.15). There was a positive significant relationship between host dbh and liana dbh in the PES (p < 0.001, r2 = 0.23) and TSS (p = 0.024, r2 = 0.11). Tree diversity appeared to have influenced liana species richness and abundance.  相似文献   

7.
This article analyzes the relationship between forest resources, refugees, and the host population. The findings of the research suggest that the host population are heavily dependent on the local forest for their daily needs such as fuelwood, timber, grazing area, fodder for domestic animals, foods, and medicine in addition to cultural and esthetic needs. The forest has also been relied upon for agricultural needs such as manufacture of agricultural tools, maintenance of irrigation water systems, erosion control, and fertilizer needs. The forest was under a sustained demand as any other Terai forest of Nepal. After the arrival of refugees in 1992, the demand for forest resources increased substantially. Initially, the construction of the refugee camps decreased the total forest area and also required some felling of trees. More significantly, the refugees themselves became active users of the forest resource, which generated extra pressure on the forest and created scarcity of forest resources. Before the arrival of the refugees, forest management and monitoring of illegal use of the forest resources were carried out by the government through its local forester office. The local residents were active users of the forest resources, but were passive in managing and maintaining the forest resource. However, competition from the refugees instilled a desire in the local population to safeguard and protect the dwindling resource against the external threat by creating the Humse Dumse Community Forest.  相似文献   

8.
In the present study, the impact of logging was assessed on the forest structure, richness, and composition of trees, lianas, and ground herbs in Indonesian Borneo. There were no significant differences in tree height, diameter, basal area, or abundance between unlogged and logged forest. Liana abundance was higher in logged than unlogged forest, but the difference was marginally nonsignificant. There was also no significant difference in the percentage cover of ground herbs. Tree species richness was similar between unlogged and logged forest, while liana species richness was higher in logged forest and herb species richness between unlogged forest. Tree and liana compositions differed significantly between unlogged and logged forest, but logging explained only a small part (<7%) of the variance in composition. In contrast to trees and lianas, ground herb composition did not differ significantly between unlogged and logged forest. Our findings indicate that the modest extraction intensity practiced did not have a severely adverse impact on forest structure or plant composition. This highlights the important role that logged forests may play in conserving biodiversity and the need to protect these forests from further disturbance.  相似文献   

9.
The global to local-level importance of Indonesian forests for the environment and development is now very well documented. However, how to govern these forests to achieve the diverse and, at times, conflicting interests is still an open question. Hutan Kemasyarakatan (HKm) is a community forest (CF) that is being implemented to contribute to local development while creating sufficient incentives for conserving the forest. Previous studies have demonstrated the potential of HKm to conserve forests. This study analyzed the changes in the five major types of capital for HKm farmers. The results indicated HKm to have contributed positively to the improvement of natural, physical, and human capital. In addition to its direct impact, HKm was also found to improve the financial capital of the farmers by avoiding patron–client relationships and side payments between the pre-HKm illegal encroacher farmers (now legal land cultivators) and government officers. Although the results support the possibility of HKm producing a win-win situation between forest conservation and rural development, its future applicability, especially with consideration of population growth and associated increase in demand for cultivation land, needs to be given due emphasis.  相似文献   

10.
针对黑龙江省森工林区森林资源经营管理工作中存在的问题,全方位阐述了推进改革和促进发展的对策。  相似文献   

11.
Three Pinus tabulaeformis populations which experienced tending, shelterwood cutting, and closed tending were separately investigated to study the effects of these three forest practices on the age structures, static life tables, survivorship curves, and species diversities of P. tabulaeformis populations in Huanglongshan Mountain. Time sequence model was adopted to predict the dynamic population numbers of different P. tabulaeformis populations with different forest practices. The results revealed that the three populations are essentially identical in population structure, their young and old individuals make up a small proportion and their mid-aged individuals make up a large proportion and consequentially P. tabulaeformis populations generally stand stable. In the P. tabulaeformis communities with three tending practices, the highest species abundance index appears with tending and shelterwood cutting and the highest evenness index and species diversity appears with closed tending. The P. tabulaeformis populations with tending and shelterwood cutting practices belong to one developmental type and the P. tabulaeformis populations with closed tending practices belong to a stable type. It indicated that in the future, closed tending as the major practice and tending and shelterwood cutting as the supporting practices should be applied for P. tabulaeformis populations in Huanglongshan Mountain so that the communities will develop continuously. __________ Translated from Acta Botanica Boreali-Occidentalia Sinica, 2006, 26(5): 1,007–1,013 [译自: 西北植物学报]  相似文献   

12.
应用样方调查法,研究分析了广东潮安凤凰山省级自然保护区内2片保护状态较好的次生林群落的植物组成和物种多样性特点.在两个面积为1200 m2的调查样方内,共记录了112种维管植物,隶属于48科77属.次生林优势科为茜草科、山茶科和樟科.乔木层优势种为阿丁枫(Altingia chinensis)、尖叶假蚊母树(Disty...  相似文献   

13.
本文根据长白山顶级森林群落特点及林区现状,以现代林业理论为指导,以吉林省汪清林业局采育林模式为支撑,以林区大量森林调查数据为基础,提出了吉林省长白山采育林经营技术规程编制原则、内容及论据等,旨在用于指导吉林省长白山林区的森林经营。  相似文献   

14.
Wood-decaying fungi are essential for the functioning of forest ecosystems. They provide habitat for many other organisms and enable the regeneration of forests throughout the world. Since wood decomposition is a decisive process in nutrient recycling, soil formation and the carbon budget of forest ecosystems, it is receiving increasing attention from forest ecologists, pathologists and managers. Research has focussed on the factors driving the species-richness of wood-decomposing organisms and is moving on to analyse the effects of this species-richness on ecosystem functioning. Coarse woody debris (CWD) and its associated wood-decaying organisms have been drastically reduced in abundance and diversity by forestry and so these features often have potential as conservation indicators. Protective measures at a landscape level are needed for threatened wood-inhabiting fungi. These include restricting salvage operations in windthrow stands, actively encouraging the accumulation of deadwood in forests, and facilitating decay in standing trees by inoculating them with fungi. Here, we aim to collect and summarize recently produced work on deadwood ecology, pointing out research gaps and perspectives.  相似文献   

15.
Understanding soil processes is fundamental to the success of forest restoration programs. We compared different types of soils in Mediterranean mountain forests with respect to their edaphic environments and influence of vegetation cover and lithology. We then used this information to determine the suitability of current forest restoration programs in these ecosystems.  相似文献   

16.
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   

17.
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   

18.
In Mediterranean environments, availability of water and nutrients are the main factors limiting the success of afforestation. As part of a wider project, an experiment was established in Northeast Portugal, aiming at testing the effect of several site preparation techniques on plant survival and growth (height and diameter) in a newly installed mixed forest stand. Results presented regard plant response during 42 months after plantation. The experimental protocol consisted in seven treatments described by mechanical operations that rank soil disturbance intensity from none to high, set in plots of 375 m2, randomly distributed in three blocks, in different topographic positions (gentle slope plateau, moderate slope shoulder, and steep mid-slope). Pseudotsuga menziesii (PM) and Castanea sativa (CS) forest species were planted in a 4 m × 2 m scheme and in alternate rows with 12 plants on each row per plot, summing up 72 plant per specie and treatment at start of the experiment. The results show that: (i) the highest mortality was observed immediately after the plantation and before the dry season, on the lowest intensity treatments; (ii) after the dry season, the highest mortality was also observed in treatments with the lowest intensity of soil disturbance, while the lowest values were found on the intermediate intensity treatments; (iii) during the experimental period, the effect of treatments on plant growth (height and diameter) was statistically significant; however, experimental results do not lead yet to a clear quantitative relationship between soil disturbance intensity due to site preparation and plant response under the conditions tested.  相似文献   

19.
Community dependence on forest resources for diverse needs has high implications for long term management of forests. Sustainable extraction of non-timber forest products (NTFPs) is considered best feasible strategy for forest conservation in biodiversity rich areas. This paper examines the heterogeneity of NTFPs use by tribal communities in northeast India, a global hot spot by examining diversity of NTFPs at-large, its consumption pattern, and contribution to rural income and forest revenue. A total of 343 NTFPs recorded used for diverse purposes by tribal communities. When species choice grouped as per use category, utilization for medicinal (163 species), edible fruits (75 species) and vegetables (65 species) purposes was reasonably high. Community dependence on forest resources was 100% for firewood and house construction material. 76 plant species were sold in three major local markets while an additional 22 species traded at commercial scale mainly outside the state. NTFPs contributed 19-32% of total household income for different tribal communities, which was significant. Illicium griffithii, Rubia cordifolia, Oroxylum indicum, Swertia chirayita, Litsea sebifera, Taxus wallichiana, Valeriana jatamansii, Thalictrum foliolosum, Picrorhiza kurrooa, Everniastrum cirrhatum, Cordyceps sinensis, Aconitum fletcherianum, Nardostachys jatamansi, Picrorhiza kurrooa, Gymnadenia orchidis, Calamus, Quercus and Pinus roxbughii were important commercial species. NTFPs also generated substantial revenue to the State government, though it is falling year after year, which is alarming. To meet community livelihoods, income and forest revenue from NTFPs, it desires a thorough management plan and policy guidelines for these resources from all line departments. The knowledge on diversity, its consumption pattern, and contribution to rural income and forest revenue may enable planners to accurately plan sustainable management of NTFP resources and community development in near future.  相似文献   

20.
We studied the impacts of liana cutting as a forest management tool on liana diversity(species richness,Shannon diversity index) and community structure(diameter distribution, basal area, species dominance) in the Asenanyo Forest Reserve, Ghana. Two types of silviculturally treated forests were studied: Logging treated(LT)and Tropical Shelterwood System(TSS) treated forests. An untreated primary forest was included as a control, resulting in three forest management systems. Lianas with diameter C2 cm were identified in ten 40 9 40 m2 plots within each management system. Liana cutting significantly reduced liana species richness, Shannon diversity index, and basal area in the LT forest after two decades.However, liana species richness and basal area werecomparable in the TSS treated and untreated forests, indicating significant recovery in the former after over six decades. S?rensen similarity index of liana species composition between the untreated forest and each of the treated forests was moderate. Our findings suggest that liana cutting most likely influenced the dominance of some liana species. In view of the adverse impact of blanket liana cutting on liana diversity, selective liana cutting is recommended as a means of controlling liana numbers while maintaining liana diversity.  相似文献   

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