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1.
We studied the effects of line thinning on stand structure, microclimate and understory species diversity of two Cryptomeria japonica D. Don plantations in south-central Japan. In each of two study sites we compared stand structure between the thinned stand
and an adjacent unthinned stand and found that line thinning increased the growth rate of residual trees such that stand basal
area may recover within 10 years after thinning. In the thinned stand, more open canopy conditions resulted in higher maximum
temperatures on the forest floor during the early growing season than in the unthinned stand. The thinned stand had greater
understory plant species richness and biomass than the unthinned stand. This study suggested that line thinning could potentially
enhance biodiversity while simultaneously increasing tree-growth rates in overstocked Cryptomeria japonica plantations. 相似文献
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Responses of community structure,diversity, and abundance of understory plants and insect assemblages to thinning in plantations 总被引：1，自引：0，他引：1
Hisatomo Taki Takenari Inoue Hiroshi Tanaka Hiroshi Makihara Masahiro Sueyoshi Masahiro Isono Kimiko Okabe 《Forest Ecology and Management》2010
Identifying effective management operations for plantations is important for conservation of biodiversity in a plantation-dominated landscape. We tested whether pre-commercial thinning influenced community structures and could be an effective strategy for increasing diversity and abundance of plants and animals in plantations. We designated thinned and unthinned study stands in Japanese cedar (Cryptomeria japonica) plantations and compared the communities of understory vegetation, bees, butterflies, hoverflies, and longhorn beetles 1 and 3 years after thinning. The analyses of vegetation showed that pre-commercial thinning affected community structure, but species richness and vegetation abundance were not significantly affected. Thinning affected insect community structure, and both species richness and abundance of all insect groups increased 1 year after thinning. However, 3 years after thinning, significant differences only remained in the species richness of bees and the abundance of bees, butterflies, and hoverflies. These results suggest that pre-commercial thinning in plantation stands influences the community structure of understory vegetation and can be an effective way to increase the diversity and abundance of some insect groups in the short term. However, the results also suggest that the duration of the operational effects of pre-commercial thinning varies among insect groups; thus, the variable effects of pre-commercial thinning should be carefully considered in the conservation-based management of plantation stands. 相似文献
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人工林在保护香港自然环境起着重要作用,但绝大多数人工林为纯林,生态系统较为脆弱。人工林的改造对于增加林地生物多样性、提升人工林的生态服务功能具有重要意义。研究选取20 a 生的尾叶桉（Eucalyptus urophylla）林和马占相思（Acacia mangium）林进行间伐套种处理,套种密度为1665株／hm2;以不间伐林分为对照,比较间伐套种后林分的物种多样性及套种树种的生长表现。结果表明,间伐＋套种3 a后,与未间伐林分相比,尾叶桉间伐林分植物的科、属和种数分别增加了78．6％、116．7％和100％,马占相思间伐林分相反。DCA 分析结果显示,群落中灌木层和草本层物种主要聚集在尾叶桉间伐林分,马占相思未间伐林分物种数次之。与未间伐相比,间伐＋套种措施显著提高了尾叶桉林乔木层 Shannon-Wiener 指数和均匀度指数、灌木层的物种丰富度指数和均匀度指数及草本层的丰富度和 Shannon-Wiener 指数（P ＜0．05）;但马占相思间伐＋套种林分的乔木层、灌木层和草本层的 Shannon-Wiener 指数均显著低于未间伐林分（P ＜0．05）;物种多样性指标总体表现为尾叶桉间伐林＞未间伐林,马占相思未间伐林＞间伐林。套种树种在尾叶桉和马占相思林分中的早期生长表现良好,树种间生长量没有明显差异。 相似文献
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In Japan, selective thinning is a common thinning method, though line thinning receives much attention because of its economic merits. In this study, we examined effects of the two thinning methods on bird communities in Todo fir (Abies sachalinensis) plantations in Hokkaido, Japan. We surveyed bird species in forests under four different management types — unthinned, selectively thinned, line-thinned plantation, and naturally regenerated forest (here after referred to as natural forest) stands — using a line-transect method. We also investigated vegetation structure (canopy tree and understory) of these stands. Bird species richness did not differ between natural forests and plantations, while bird total abundance was greater in plantations than in natural forests. Bird species richness and total abundance were comparable among the three management types for plantations. Abundances of 10 bird species were different among the four management types, and five species were more abundant in line-thinned plantations. However, two species were more abundant in selectively thinned stands than in line-thinned stands, and they frequently appeared in natural forests. There were no distinct differences in vegetation structure among the management types for plantations. Our results suggest that line thinning could be beneficial for some bird species in plantations. 相似文献
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Toshiya Yoshida Mikio Hasegawa Hideaki Taira Mahoko Noguchi 《Journal of Forest Research》2005,10(5):351-358
Tree retention is understood as a key practice in creating complexity, leading to heterogeneity in resources and habitats in managed stands. In this article, we clarify the long-term effects of tree retention on stand structure and tree-species composition in a 60-year-old Larix kaempferi plantation in central Japan. In our study plot (1.5 ha) there were 18 stems/ha of retained trees (determined by tree-ring analysis), mostly Quercus crispula. We conducted spatial analyses and tested the hypothesis that tree abundance, size structure, and species composition and diversity change with distance from the retained trees. Near the retained trees, L. kaempferi showed a reduction of 40%–60% in basal area, due presumably to the shading effect. In contrast, the nearby area showed greater species diversity in the canopy layer. The retained trees created patches of different species composition in the understory. The spatial gradient of shade and colonization opportunity provided by retained trees greatly affect the distribution of the colonized species, according to their shade tolerance and seed-dispersal ability, which resulted in the stand structure with a heterogeneous shrub-layer vegetation. Retention proved particularly important for the enhancement and long-term maintenance of structural and compositional complexity in L. kaempferi plantations. 相似文献
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Xiangdong Lei Yuanchang Lu Changhui Peng Xiaopeng Zhang Jie Chang andLingxia Hong 《Forest Ecology and Management》2007,240(1-3):165-177
Analyzing and understanding the structure and growth dynamics of semi-natural plantations is useful for their management. Since 1987, 16 plots with 4 treatments (CT: control; LT: light thinning; MT: medium thinning; and HT: heavy thinning) by 0, 20, 30 and 40% of basal area removal, respectively, and four replications were established in semi-natural larch-spruce-fir forests in northeast China. The structure and growth dynamics of semi-natural larch-spruce-fir stands and the effects of thinning on the growth, structure and diversity were examined. A mixed model repeated measures analysis of variance (RMANOVA) was used to test the effects of treatment and time.
Results showed that differences in periodic annual increment (PAI) of stand basal area and volume and the individual diameter and volume among treatments changed over time in a complex statistical interaction. Thinning, however, had a significant effect on growth at tree and stand levels 12 years after thinning while the PAI of the diameter, basal area and volume was positively correlated with thinning intensity. No significant differences were found in the total stand yield among treatments. Composition of tree species group (larch, other conifers and deciduous trees) during monitoring years did not change significantly. Moreover, no significant differences were observed in tree species and size diversity among treatments in the years following thinning. Both thinning and control plots had similar understory plant diversity after the 12 year period. Univariate point pattern analysis revealed that clumped and random distributions were dominant for tree species groups in this study. The current species composition and regeneration dynamics within these semi-natural plantations suggested a development towards mixed coniferous and broad-leaved forests. Management implications for the transformation from larch plantations towards mixed broad-leaved Korean forests with a more diverse structure, the climax vegetation in this region, were discussed. 相似文献
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Based on paper of “Theoretical derivation of risk-ratios for assessing wind damage in coastal forest“,wind damage in the pine coasteal forest,which was thinned at four levels in December of 1997,was investigated for four successive growing seasons.Besides wind damage,the wind profiles outside and inside the coastal forest stand and the distributions of optical stratification porosity (OSP) were also observed.Based on these data,risk-ratios of wind damage for both individual trees and stands were estimated according to the methods developed in “Theoretical derivation of risk-ratios for assessing wind damage in a coastal forest“.The results showed that risk-ratios of wind damage,which were calculated from the meen height and diameter only and from the combination of wind and stand sructure profiles,accurately predicted wind damage in the plantation.Relationships between different thinning ratios and incidence of wind damage showed that stand stability decreased soon after the thinning.This was due to the immediate effects of thinning on increasing the canopy roughness and wind load,and on decreasing the sheltering effects from surrounding trees.However,thinning strategies could improve the stability by long-term effects on growthand development of trees against extreme wind.Only canopy damage was recorded during the experimental period,no stem damage was found,even though the maximum 10-min wind speed outside the coastal forest attained 30.2m s^-1.The results obtained in this study indicate that thinning is the most effective silvicultural strategy available for managing coastal forest despite the increased probability of wind damage soon after thinning. 相似文献
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Tomohiro Nishizono Kunihiro Tanaka Kazuo Hosoda Yoshio Awaya Yasuhiko Oishi 《Journal of Forest Research》2008,13(5):264-274
We analyzed data from 28 long-term experimental monitoring plots installed in Japanese cedar (Cryptomeria japonica D. Don) plantations in northeastern Japan to examine how site productivity and thinning practices relate to culmination in
stand growth. Site productivity and thinning practices in the plots were evaluated by site index (dominant tree height at
40-years old) and by cumulative thinning rate (cumulative thinning volume divided by cumulative gross production during the
entire period of measurement). Culmination of stand growth was evaluated by culmination age of the mean annual increment (MAI)
and its maximum value (Max MAI). Max MAI for the mean annual gross increment (MAIgross) and mean annual net increment (MAInet)
increased with increasing site index, but did not change with cumulative thinning rate. Culmination age for MAIgross decreased
with increasing site index, but did not change with cumulative thinning rate. Culmination age for MAInet decreased with increasing
site index. Additionally, culmination age for MAInet increased with increasing cumulative thinning rate in sites with a high
site index (>19.3 m) but not in those with a low site index (<19.3 m). These results indicate that thinning extends the culmination
age without changing Max MAInet under high site productivity. Therefore, thinning increases total net yield in sites with
high productivity based on a long-term perspective. 相似文献
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Tree plantations can be an important tool for restoration of abandoned pasturelands in the tropics. Plantations can help speed up secondary forest succession by improving soil conditions, attracting seed-dispersal agents, and providing shade necessary for understory growth. In this study, abundance and richness of understory regeneration was measured in three native tree plantations 15–16 years of age at La Selva Biological Station in the Costa Rican Caribbean lowlands. Each plantation contained tree species in pure plots, a mixture of the species, and natural regeneration plots (no trees planted). The greatest abundance of regeneration was found in the understory of pure plots of Jacaranda copaia (Aubl.) D.Don., Vochysia guatemalensis Donn.Sm., Dipteryx panamensis Benth, Vochysia ferruginea Mart., and in two mixed stands, while the lowest was found in the natural regeneration treatments with about half the values as in the plantation stands. There was a significant negative correlation between percent canopy openness and abundance of regeneration in the understory. Two distinctive clusters separated the regeneration treatments from the mixed and pure plantations at a very low Bray–Curtis similarity value. The natural regeneration treatments are separated from mixed and pure plantations in the two-dimensional ordination. The lack of difference between the understory make-up of pure and mixed plantations in abundance, species richness, and seed-dispersal syndromes of understory species suggests that planting mixed stands is not necessarily superior to planting pure stands for promoting understory diversity of woody species. While regeneration of woody species can be faster under pure- or mixed-species plantations than in open pastures, the abundance, richness and species composition depends on each plantation species, or species assemblages in case of the mixtures. 相似文献
13.
[目的]以河南登封林场栓皮栎人工林为研究对象,研究抚育间伐对林分不同生长阶段林木株数、林木直径分布和树高分布的影响,为制定科学合理的抚育经营措施奠定理论和技术基础.[方法]在株数强度为31.55％的间伐林分和条件基本一致的未间伐林分内,分别设置1个1 hm2样地,间伐作业2 a后获取每木检尺数据,分别利用Normal分... 相似文献
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The species richness of trees, shrubs and climbing plants was investigated in 41 sugi (Cryptomeria japonica D. Don) plantations of different stand age and area in southern Kyushu, southwestern Japan. Altogether 174 species were found,
of which 145 infrequent species were selected for analysis. Two groups were extracted from the species list according to their
occurrence in older (49 spp.) or younger (28 spp.) stands, the latter containing a higher percentage of climbing plants and
species with wind-dispersed seeds. In contrast, the older stand group contained major tree components typical of seminatural,
evergreen broadleaved forests in the region and was more heavily dependent on stand age, especially for species with gravity-
and frugivore-dispersed seeds, showing a gradual increase up to 60 years old. The species richness was less correlated with
edge perimeter facing seminatural forests and the years after latest thinning. The juxtaposition of plantation compartments
with stands of seminatural forest or other plantations, as well as the compartment's origin as former plantation site or a
seminatural stand, had relatively little influence on species richness. However, topographic variation was important in determining
the species composition, with valley stands having higher species richness and containing many plants typical of the regional
seminatural forests. These results suggest that (1) the major trend of species richness is determined by the presence of old
stand type species, (2) topographic variation of species richness remains even after establishment of plantations, and (3)
the normal rotation period of sugi plantations (35–40 years) may therefore be too short to conserve the maximum potential
species diversity within the working forest.
Received: June 4, 2001 / Accepted: August 26, 2002
Acknowledgments We wish to thank the staff of the Miyazaki University Forests for cooperation in the fieldwork. A part of this study was
supported by the Grant-in-Aid for Scientific Study from the Ministry of Education, Science and Culture of Japan (no. 09041071
and no. 10460068).
Correspondence to:S. Ito 相似文献
16.
Hiromi Yamagawa Satoshi Ito Yasushi Mitsuda Kazuro Fukuzato 《Journal of Forest Research》2006,11(2):99-106
We investigated factors limiting the recovery of natural forest in former large-scale conifer plantations abandoned after
clear-cutting in southwestern Japan. We analyzed forest recovery status (“recovered” sites covered by evergreen broad-leaved
trees, and “unrecovered” sites covered by pioneer community or nonvegetated sites) using aerial photographs and field survey.
We applied logistic regression analyses to evaluate the effects of topography, construction of harvesting roads, distance
from remnant forest, stand condition before clear-cutting, and prior land-use history on forest recovery. Human factors, i.e.,
land use and clear-cutting age, were found to affect to forest recovery more than environmental factors such as topography.
Harvesting roads had the strongest negative impact on forest recovery. Forest recovery after clear-cutting of young sugi plantations
also took longer than after clear-cutting of old sugi plantations or evergreen broad-leaved forests. Furthermore, areas formerly
utilized as meadows recovered less successfully than those that had been managed as coppices. The influences of these factors
were thought to be promoted by the advance reproduction as the regeneration sources for forest recovery. The influence of
stand age before logging suggested an effect of thinning, which might alter the abundance of advanced reproduction in the
understory. However, distance from remnant forest appeared to be less important. An influence of topography was also detected,
but this could be partly explained by the existence of advance reproduction in the understory in certain topographic positions.
Thus, our analysis suggests that regeneration sources originating from advanced reproduction in plantations play a significant
role for the recovery of natural forest after clear-cutting. 相似文献
17.
Yuichi Yamaura Hitoshi Tojo Yasumasa Hirata Kenichi Ozaki 《Journal of Forest Research》2007,12(4):298-305
It is important to conserve forest-dependent organisms not only in broadleaved forests but also in plantation forests. We
examined how surrounding forest areas affect forest bird assemblages inhabiting conifer plantations and broadleaved forests
in a rural landscape in central Japan. Surrounding forest areas were measured separately as plantation area and broadleaved
forest area within 200 m of each sampling site. We used hierarchical partitioning to analyze the effects of surrounding forest
areas and stand structures (stand height and understory coverage) on the occurrence of four species groups. We especially
focused on mature forest users that are most sensitive to loss of broadleaved forests. Occurrence of mature forest users inhabiting
plantation sites was positively affected both by plantation area and broadleaved forest area whereas the occurrence of mature
forest users inhabiting broadleaved forests was affected by stand height only. These results suggest that surrounding forest
areas were more important to mature forest users in plantations than in broadleaved forests. To conserve mature forest users,
increasing surrounding forest areas are important in plantations whereas increasing stand heights would be effective in broadleaved
forests. 相似文献
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Patterns of stand growth and dominance among individual trees change through stand development. We tested a prediction that large, old plantations of Eucalyptus saligna (Sm.) in Hawaii and Brazil would show a pattern of “reverse” growth dominance, with the largest trees contributing more to stand biomass than to current stand increment. This pattern might develop if the largest trees accounted for a large portion of the total resource use of the stand, but were less efficient at utilizing resources to produce stemwood. The 70-year-old plantation in Hawaii had a stem mass of 610 Mg/ha, compared with 325 Mg/ha in the 66-year-old Brazil plantation. Cumulative frequency plots for both sites showed that dominant trees comprised a very large proportion of total stand mass; the largest 20% of the trees accounted for 50% and 30% of the total stand mass in Hawaii and Brazil, respectively. Contrary to expectations, the largest trees continued to produce a disproportionately large amount of total stand growth, with the largest 20% of trees accounting for 60% (Hawaii) and 40% (Brazil) of stand growth. The frequency distributions resulted in positive growth dominance coefficients (similar to Gini coefficients) of 0.14 for Hawaii and 0.09 for Brazil, rather than negative values that would indicate that reverse growth dominance. The failure of these monoculture Eucalyptus stands to develop reverse growth dominance contrasts starkly with a variety of studies with pine species, which tend to show neutral-to-reverse growth dominance. Indeed, continued dominance of large trees suggests the trees might respond well to silvicultural treatments such as thinning or fertilization. Future work that contrasts patterns of growth dominance among species will be important as a foundation for developing generalizations about trends in growth dominance with stand development. 相似文献