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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
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《Scandinavian Journal of Forest Research》2012,27(1-4):375-387
To avoid large clear‐cut areas in recreation areas, three experiments where group selection was used to transform even‐aged stands of Norway spruce (Picea abies (L.) Karst.) into uneven‐aged stands were started. Two of these group selection stands were compared with adjacent forests managed by the clear‐cut system on the basis of the opinion of seven voluntary groups. The respondents have given their judgement of the forest sites in a semantic differential test. All parties made assessments when visiting the forest sites. In addition, two of the groups made assessments of black and white photographs representing the forest sites. The methods used were found to be both reliable and valid. A very low correlation was obtained between the assessment of whole forest areas and the mean value of the assessments of the stands within the same area. According to this study, the group selection method is preferable to clear‐cutting in even‐aged stands of Norway spruce if the attitudes of the voluntary groups are to be met. 相似文献
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A new method for predicting understory light levels around an artificial canopy gap prior to the selective cutting is presented.
In two even-aged coppice stands, hemispherical photographs were taken at a height of 1.3 m, and crowns of each canopy stem
on the photographs were identified by field observations. To predict light levels after cutting, we used computerized images
of the hemispherical photographs, in which we digitally erased all crowns to be cut (named ‘erasing method’). Light levels
were calculated by an analyzing program; HEMIPHOT. Light levels predicted by the ‘erasing method’ were compared with that
calculated by the ordinary photograph-analyzing method using photographs taken after the actual cutting. The correlations
between the two methods were highly significant in the two stands. The ‘erasing method’ is eminently effective for the prediction
of understory light levels in an artificial canopy gap. 相似文献
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1999年春鄱阳湖鹤类和大型水禽航空调查报告 总被引:9,自引:0,他引:9
通过调查,基本查清鹤类和大型水禽在鄱阳湖的越冬分布状况及栖息地生境特征。 相似文献
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利用航空象片信息提取小班调查因子。首先利用航片对每个小班的林分类型、龄组、郁闭度和最大冠幅进行判读;其次根据以往的资料,建立林木株数分布,每公顷株数预测,直径与最大冠幅及胸径与树高、年龄等相关模型;最后由判读因子和上述模型借助于计算机求出林分蓄积量、断面积、各径阶株数,平均直径、平均高、平均年龄等因子。该试验是在我国北方次生林区进行的,多数小班因子可由航片提取,蓄积量估测的精度达到85%以上,可提高工作效率1—2倍。为我国二类森林调查提出了一种新的方法。 相似文献