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1.
《Journal of Sustainable Forestry》2013,32(1-2):203-221
Abstract Two Abies firmaforests, one on an island (Kinkazan Island) inhabited by Sika deer (Cervus nippori)and another on the opposite peninsula in northern Japan, were compared. Species richness was poorer on the island than on the peninsula, and only low growing plants (rosettes or prostrate forms) and unpalatable plants were found there. The biomass in the forest floor in the island plots was only about 10% ofthat on the peninsula plots. Densities of woody plants in the island plots were much lower (350-600 stems/ha) than those in the peninsula plots (1400-2300 stems/ha). The size class distributions of woody plants were biased toward larger size classes in the island plots, indicating that these stands were older and lacked young trees. In contrast, the tree sizes were variable among the peninsula plots, suggesting that the peninsula forest was logged in different years. Sika deer seemed to have prevented the regeneration of the A. firma forest on the island by removing most of the seedlings and saplings. Proper population control of the deer is necessary for healthy forest regeneration. 相似文献
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在南韩东北部,1997-1998年间,自4月至12月对人工林和无枯死木生境及采伐后保留地被物的落叶次生林中的小型鼠类种群特征进行了调查。在两块林地中各选择1 hm2(100m100m)样地作为控制区和处理区。两块研究地的中上层林冠结构基本相似,但倒木及地被物的数量及比例却显示控制区大于处理区。两区域中共捕到两种小型鼠类,其中棕背 (Eothenomys regulus)211只,占总数的55.5%,大林姬鼠(Apodemus peninsulae)169只,占44.5%。这两种鼠类的丰富度及种群稳定性在控制区明显优于处理区。两地小型鼠类的不同捕获量主要来自两地鼠类繁殖率和居留率的不同。显然,森林地被结构对小型鼠类的生存具有重要意义。因此,采伐迹地中保留枯死木及地被物是维持小型鼠类种群所必须的。 相似文献
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Overabundant white-tailed deer (Odocoileus virginianus) are a significant management problem in North America that exerts unprecedented herbivory pressure on native understory forest communities. Conserving understory plant populations requires quantifying a sustainable level of deer herbivory. To date, most population projection models consider only deer presence and absence. To estimate population growth rate along a gradient of herbivory, we focused on Trillium grandiflorum because it is a common understory species and a bellwether of deer effects and forest decline. We used matrix population models, and employed both prospective and retrospective analyses using a regression life table response experiment (LTRE). 相似文献
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The intensity of deer herbivory, rather than simply the deer population density, directly affects the forest ecosystem, but a linear relationship between these two factors has generally been assumed. To assess their relationship, we investigated deer population density and tree sapling vegetation in six forests with different deer density on Yakushima Island, Japan. The feeding frequency was used as an index of deer herbivory. Palatable saplings showed high feeding frequency and became rare in deer-abundant areas, while unpalatable saplings showed low feeding frequency and increased with increasing deer density. In addition, feeding frequency on sapling vegetation did not continue to increase with increasing deer population and was limited to only 0.24-0.32 in deer-abundant areas (more than 20 deer/km2). These data suggest that deer shift their main food items from living palatable saplings to other alternatives such as litter fall rather than living unpalatable saplings. Clearly, the nonlinear relationship between deer density and deer herbivory on forest vegetation could result from a change in the food eaten by deer, and it is therefore necessary to assess the impacts of deer based on not only the size of the deer population but also the intensity of direct herbivory. 相似文献
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Sika deer (Cervus nippon) cause serious damage to trees in Japanese forests. Browsing, bark stripping, and tree abrasion with antlers account for 50% of total wildlife damage over the past decade. The extent of forest damage depends on deer population density. We determined the spatial distribution of sika deer population density on Mt. Hiko (Fukuoka Prefecture, southwestern Japan). We also investigated changes in population density distribution over time. Determinants of population density were examined, with particular emphasis on the hunting cull. Deer densities in 1999 and 2004 were estimated by fecal pellet counts at 86 sites. We used kriging, a geostatistical technique that is a component of geographic information systems, to interpolate site-specific point data over large areas of landscape. Mapping procedures showed that high-density (≥30.0 deer km?2) and low-density sections of landscape (≤10.0 deer km?2) decreased in areal extent between 1999 and 2004. Contractions of high-density sections were attributable to intensive hunting. In low-density landscape sections, reduced hunting pressure allowed increased persistence of adult animals whose high fecundity led to population growth and higher deer densities. Landscape tracts with medium deer densities (10.0–30.0 deer km?2) expanded, adding further difficulties to the task of wildlife management. Given the scale of the problems caused by deer, it is clear that reliable estimates of population size across space and time are essential components of the wildlife manager’s toolbox. 相似文献
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Preston R. Aldrich George R. Parker Jeffrey S. Ward Charles H. Michler 《Forest Ecology and Management》2003,180(1-3):475-491
An analysis of spatial dispersion was conducted for individual tree species in the old-growth forest at the Davis-Purdue Research Forest in Indiana. This 20.6 ha stand has been left largely undisturbed by exogenous factors since its acquisition by Purdue in 1917. It is the only long-term study plot of its size for a temperate hardwood forest with x–y coordinates (rectangular plot) for all species above 10 cm diameter. Full censuses have been conducted spanning 60 years (1926, 1976 and 1986).
Ripley’s L(t) function revealed that most species are characterized by some form of aggregation, agreeing with a prior evaluation from 1981. Heterogeneity of spatial structure was evident between two large plots, indicating that differences in site quality and history had influenced spatial structure. Shade-intolerant species were numerically dominant and spatially aggregated in 1926 but have declined over the 60-year interval and become more random in spatial dispersion. Shade-tolerant species have increased in number and become more aggregated over time, or they exhibit little change in spatial structure. Examples of the latter include Acer saccharum and Ulmus americana, species that experienced explosive population growth. These contrasting patterns are masked by stand-level patterns that show a trend toward uniformity over the same time frame.
These data reveal that changes in dispersion accompany the demographic failure experienced by numerous tree species in Central Hardwood old-growth stands, and these changes may feed back into a negative population cycle and further impede regeneration. The simultaneous manipulation of dispersion and density should be considered as a tool for influencing forest succession and promoting regeneration of desired tree species. 相似文献
8.
Sika deer (Cervus nippon) sometimes cause extensive damage to planted tree seedlings. To evaluate the effects of culling on the spatial distribution patterns of sika deer and browse damage to planted seedlings, we compared the data collected before and after experimental culling in a cool, temperate, mixed forest on Kyushu Island, Japan. Experimental culling, conducted in an area of 1 km2, removed five, four and two sika deer in April, June and October 2011, respectively. During the year before culling, the spatial pattern of the number of sika deer caught on camera corresponded to the predicted sika deer density. Sika deer immediately browsed planted seedlings after the initial planting. The cumulative number of browsed seedlings increased over time, especially in winter. The spatial pattern of the cumulative number of sika deer caught on camera corresponded to that of browsed seedlings at the year’s end. During the year when culling was conducted, the number of sika deer caught on camera decreased around the center of the study site where the culling was conducted and the number of browsed seedlings decreased. During the year following culling, the cumulative number of browsed seedlings was very similar to that in the year before the culling, while the same low number of sika deer was caught on camera. These results indicate that the effects of deer culling resulted in decreased levels of sika deer appearance and browse damage for more than 1 year and for several months, respectively. 相似文献
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Habitat structure in Oku-Nikko, Japan, has been substantially modified by the overabundance of sika deer (Cervus nippon). A deer-proof fence (15.0 km and 900 ha) was constructed in 2001 to conserve vegetation. Although the understory inside the fence is dominated by Sasa nipponica (hereafter, Sasa), an important forage plant for deer, that outside the fence is dominated by Aster ageratoides leiophyllus (hereafter, Aster), an unpalatable plant to deer, and, partly, by bare floor. In this study, we examined the effects of deer on ground-dwelling insects and earthworms, the primary food resources of raccoon dogs (Nyctereutes procyonoides), and, thus, the bottom-up cascading effects of the herbivore on the omnivorous carnivore. Between July and September 2008, we examined the abundance of insects and earthworms by pitfall trapping and hand-sorting methods, respectively, both inside and outside the fence. The abundance of earthworms and insects (Scarabaeidae and Rhaphidophoridae) was higher on forest floors with Aster and/or bare floors outside the fence than on those with Sasa inside the fence. These results indicate that the increasing deer population in this area probably increased the number of these invertebrates outside the fence by modifying understory vegetation and/or depositing dung. Furthermore, the sighting rates of raccoon dogs obtained by spotlight counts were greater outside than inside the fence, suggesting that deer probably exert bottom-up cascading effects on raccoon dogs, at least during May to November, when the invertebrates are predominantly fed on by the omnivorous carnivore. 相似文献
10.
虫情监测是森林害虫综合治理的前提。直接观测虫情,常因树木高大而难以实现。对我国林业大害虫马尾松毛虫(Dendrolimus punctatus),已有较理想的模型,通过对林间落粪的调查来估计幼虫数。由于低密度虫情监测尤为困难,而用落粪作间接观测的价值就随之增加,林间一定时段内的落粪是幼虫种群在该时段内活动的结果,其分布则是该时段内种群分布的综合反映。可以设想,落粪分布与种群分布间存在一定关系。对落粪的调查取样,应建立在了解其分布特征的基础上。为此,研究了低密度幼虫种群的空间分布型及落粪分布的规律。 相似文献
11.
Hiromitsu Kisanuki Mafumi Nakasu Arisa Nakai Yutaka Yurugi 《Journal of Forest Research》2008,13(1):52-58
We examined the population dynamics of three broad-leaved tree species with different susceptibilities to deer predation.
Simulation analysis was conducted using a size-structured matrix model for a primary forest plot (PP) and a secondary forest
plot (SP) with 56% and 12% evergreen conifer composition in the canopy, respectively. In both plots, populations of Neolitsea sericea, a species that is susceptible to deer predation, initially declined significantly but eventually leveled off. The number
of small stems decreased, while that of larger stems increased, indicating that the population dynamics of N. sericea are strongly affected by browsing pressure and that the number of large trees is important for population maintenance. When
we examined two deer-resistant species, Pieris japonica and Illicium anisatum, the population of P. japonica increased in the SP and decreased in the PP, whereas that of I. anisatum increased in both plots, likely because mortality tends to increase in persistently dark environments. No significant difference
was observed between the present and predicted size distributions of resistant species in the PP. Competition for resources
is expected to intensify in the SP as a result of the predicted increase in large stems of the resistant species I. anisatum. Therefore, a specific conservation and management strategy for tree species should be considered for each forest type under
the influence of Sika deer. 相似文献
12.
Understory individuals were found to form patches in a 100-year-old deciduous broad-leaved forest. The closed forest canopy
was uniform, and so the light conditions at various locations across the forest floor differed little after the leaf flush
of the overstory. To explain the distribution pattern in the understory, a hypothesis was proposed: in spring, the forest
floor is divided into patches according to the timing of leaf flush of the overstory individuals, and the light conditions
are more favorable for understory plants under the crowns of trees with later-flushing leaves. In the plot, three groups of
early, intermediate, and late, were recognized in the overstory concerning the timing of leaf flush. As for the start of leaf
flush, a difference of 31.6 days was recognized among tree species, and for the end of leaf flush, a difference of 40.3 days.
In the spring of 1998, the relative photosynthetic-photon-flux density under an intensively studiedCastanea crenata tree (late-flushing species) usually showed higher values than that under a similarly studiedAcer mono tree (early-flushing species). Analysis of the spatial-distribution pattern using Morisita’s1δ index revealed that the understory community had an aggregated distribution. In the overstory, the late- and the intermediate-flushing-species
groups showed aggregated distributions, while the early-flushing-species group showed random distribution. Spatial correlation
between the understory and the overstory was analyzed by using Morisita’sRδ index. The distribution of whole understory community spatially co-occurred with that of the late-flushing-species group
of the overstory. In contrast, the understory community was less developed below the members of the early-flushing-species
group of the overstory. We consider that the data presented here support our hypothesis, and we suggest that the growth and
survival of understory individuals were promoted in the places receiving light for long periods in spring. 相似文献
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Stand structure and the regeneration ofChamaecyparis pisifera on sites with and without well-developed soil in an old-growth coniferous forest, Akasawa Forest Reserve, central Japan,
were investigated, along with their relationships to other important coniferous species. Of stems ofC. pisifera≥5 cm diameter at breast height, stems with intermediate size were absent in stands on the developed-soil site, while those
with smaller size increased in stands on the undeveloped-soil site, which supported a higher density ofC. pisifera. In the stands without recent tree-fall of canopy stems on the developed-soil site, canopy stems ofC. pisifera were distributed uniformly and the understory stems, patchily. On the other hand, both canopy and understory stems ofC. pisifera in stands on the undeveloped-soil site were distributed patchily. In the understory,C. pisifera occurred as clonal patches formed by vegetative reproduction on various types of microsites including bare rocks. However,
the clonal patches did not occur in a stand on the developed-soil site with dense saplings of an evergreen conifer,Thujopsis dolabrata, which can expand vegetatively with a well developed soil layer. Gap formation may induceC. pisifera to develop tree-form stems from shrubby clonal patches. On developed-soil sites,C. pisifera stands that survive a long disturbance-free period on this site need catastrophic disturbance for their regeneration, which
will eliminateT. dolabrata in the understory and create bare soil for colonization ofC. pisifera from seeds. On undeveloped-soil sites,C. pisifera replaces itself continuously by effective vegetative reproduction. Ground instability and the wet condition of this site
may promote the replacement. 相似文献
15.
Regeneration of commercial species is central to long-term success of multiaged management for wood production. We examined relationships between understory light, varying overstory tree retention, and growth of coast redwood (Sequoia sempervirens; commercial species) and tanoak (Notholithocarpus densiflorus) stump sprouts initiated by group selection and single-tree selection harvesting in 80–100 year old mixed stands at four sites. Treatments included a complete harvest in 1-ha group selection openings, low-density dispersed retention, and either aggregated or dispersed high-density retention. Post-harvest stand density index and basal area were useful predictors of understory light. Mean and maximum understory light did not differ significantly between treatments with the same density where residual trees were retained in aggregated versus dispersed spatial patterns. However, the dispersed retention had lower minimum light levels when compared to the aggregated retention treatment. Aspect appeared to influence understory light more in dispersed treatments. At all light levels, the dominant sprout within clumps of redwood stump sprouts generally grew faster than dominant tanoak sprouts within tanoak sprout clumps. Differences in sprout height growth between aggregated and dispersed treatments were minimal. Stump size had a significant effect on redwood stump sprout height growth, with sprouts on the largest stumps growing approximately twice as quickly as sprouts on the smallest stumps. In the low density dispersed treatment, redwood sprouts outperformed tanoak sprouts by the greatest margin. Regeneration of redwood and tanoak was most rapid within group selection openings. 相似文献
16.
Amélie Collard Line Lapointe Jean-Pierre Ouellet Michel Crête Alain Lussier Claude Daigle Steeve D. Côté 《Forest Ecology and Management》2010
We examined the response of understory plants in mature maple-dominated forests of southern Québec, Canada, following about 30 years of high deer densities, using a deer exclosure experiment. An exclosure and a paired control of 625 m2 each were established on six sites in 1998. An exclosure and a paired control of 16 m2 were added at each of the same sites in 2003 but under a recent canopy gap to determine if light could enhance plant responses. We measured plant richness and abundance, and aboveground biomass of different plant groups for 8 years in the understory plots and for 3 years in the canopy gaps. Four herbaceous species were also monitored individually in the same plots. No significant differences between treatments were found in plots under forest cover, except for lateral obstruction at 0–50 cm height which was higher in the exclosures. Under canopy gaps, however, tree seedling and total plant abundance were higher in deer exclosures than in control plots. Trillium erectum recovered partially as individuals were taller, had larger leaves and more frequently produced a flower or a fruit in the absence of deer browsing under forest cover. To a lesser extent, Erythronium americanum and Maianthemum canadense also exhibited signs of recovery but were still at the single-leaf stage after 8 years of recovery. In general, the different plant groups exhibited little recovery following deer exclusion, possibly because of the low light levels that prevailed in the understory of undisturbed maple-dominated forests. The higher latitude of the present study could also contribute to the slow recovery rates of the different groups of plants compared to studies conducted in northeastern USA. Variability among sites and years had an effect on detection of statistically significant differences. Trends are however appearing over time, suggesting that many understory plants are recovering very slowly following deer exclusion. Our results emphasize the importance of studying large herbivore–forest interactions on different groups of plants, but also on specific species, and under different latitudes to be fully understood. 相似文献
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本文基于阔叶红松林30hm2(500m×600m)固定监测样地,分析了红松在各林层(主林层、次林层、林下层)的空间分布、各林层之间的关联性。结果显示:(1)红松在各林层都在小尺度上呈聚集性分布,大尺度上呈随机分布;且在低林层聚集性强度高于高林层。(2)红松各林层关联性表现为主林层与次林层在小尺度上呈正相关,大尺度上关联性不显著;主林层与林下层在小尺度上呈负相关,大尺度上关联性不显著;次林层与林下层在所有尺度上呈现显著正相关。说明红松种子扩散和红松个体间竞争对空间分布起着重要作用。 相似文献
18.
Recent research in western North America suggests that open forage areas are a greater limiting factor to mule deer abundance than closed conifer forests. However, much of this work was conducted in ecosystems prone to fire and low snow depths compared to the limits of mule deer range such as the Columbia Mountains, British Columbia, where snow is deep and fires are rare. We used snow track surveys as a measure of habitat use and fecal nitrogen as an index of dietary quality to compare the relative value to mule deer of open deciduous canopies to closed coniferous canopies in a wet ecosystem with deep snow and few fires. Deciduous canopies contain higher levels of understory forage compared to dense coniferous canopies, which are better at intercepting snow. We also evaluated food habits across landscapes with contrasting forest canopies. Results corroborated previous work in that foraging areas such as deciduous stands were strongly selected by deer, despite deeper snow relative to closed coniferous stands. Deer consumed fewer understory shrubs in coniferous-dominated stands, suggesting lower nutritional intake in these stands. Finally, deer appeared to derive a nutritional benefit in landscapes that had a higher proportion of open deciduous canopies, as indexed by fecal nitrogen. However, not all open canopy stands were of equal value to deer – deciduous-dominated stands were selected, whereas clearcuts were avoided. Similarly, not all closed coniferous stands were equally selected: cedar–hemlock stands were avoided whereas Douglas-fir stands were selected and indeed contained the highest proportion of deer tracks. We suggest that winter foraging areas have been underrepresented in management policy in British Columbia, but that snow-interception cover provided by coniferous stands still plays a role in winter deer ecology in deep-snow ecosystems. 相似文献
19.
Theodore T. Salk Lee E. FrelichShinya Sugita Randy CalcoteJames B. Ferrari Rebecca A. Montgomery 《Forest Ecology and Management》2011,261(11):1998-2006
Anthropogenic factors such as elevated deer populations, invasive earthworms or climate change may alter old-growth forests of the Upper Midwest region of the United States. We examined demographic trends of woody species across all size classes over 35 years in a late-successional forest dominated by hemlock (Tsuga canadensis), sugar maple (Acer saccharum) and yellow birch (Betula alleghaniensis) in Michigan's Upper Peninsula using two sets of permanent plots. For the duration of the study period, species that were less-preferred white-tailed deer (Odocoileus virginianus) forage, especially sugar maple, comprised a much higher fraction of all seedlings and saplings compared to overstory trees. The density of small sugar maple declined across the study period, but no other species became more abundant, creating a more open forest understory. By the most recent census, preferred species for deer browse had been nearly eliminated from the understory, and declines in unpreferred species such as sugar maple were also apparent. We found small changes in temperature (<0.5-1 °C rise in minimum and maximum temperatures depending on season) and precipitation (±28 mm depending on season) and little evidence of invasive earthworms impacts. Our results suggest that the sustained elevated deer density is shifting the structure and composition of this old-growth forest. A demographic model showed that if current recruitment, growth and mortality rates were to continue for 500 years the forest would eventually reach a new equilibrium with virtually no hemlock or yellow birch remaining. 相似文献
20.
浅谈沙棘的综合价值 总被引：1，自引：0，他引：1
胡海东 《内蒙古林业调查设计》2014,(4):133-135
沙棘作为优良的多用途树种,以其顽强的生命力以及极强的克隆繁殖和空间拓展能力,成为了典型的克隆植物。不仅如此,其本身所具有的多重价值更值得去不断发掘。他以极耐干旱、极耐贫瘠、极耐冷热,成为了植物之最,同时,也是世界学术界发现的唯一把经济效益、生态效益和社会效益集于一身的农作物,成为了世界之最。 相似文献