The influence of forest cover on mule deer habitat selection, diet, and nutrition during winter in a deep-snow ecosystem

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.     

Population density and range use of sika deer,Cervus nippon, on Mt. Ohdaigahara, central Japan

We investigated the population density and range use of sika deer,Cervus nippon, on Mt. Ohdaigahara, central Japan, from July 1996 to July 1997. The deer population density estimated by the block count was high at 17.5–30.9 deer/km². Although the deer remained this area from spring to fall, they moved out in winter, probably because of deep snow. A spotlight count showed that the deer prefer the eastern area as spring-summer range, where the forest consists of coniferous trees over a floor cover ofSasa nipponica, andS. nipponica grassland. The deer also use dense coniferous forest for cover, especially in summer and fall. Part of this study was presented at the 108th Annual Meeting of the Japanese Forestry Society (1997). This study was financially supported by the Environment Agency, Japan.     

Development of a method for forest cafeteria tests for evaluating chemical deterrents against bark stripping by sika deer (Cervus nippon yesoensis)

Damage caused by sika deer (Cervus nippon yesoensis) is a serious problem in commercial and environmental (non-harvested) forests in Hokkaido, northern Japan. Cafeteria tests in forests may be useful for evaluating the efficacy of chemical deterrents against bark stripping by deer. To develop a method for forest cafeteria tests in the continuous snow cover period, two experiments were carried out. In the experiments, logs were produced from tree trunks, and used as carriers of chemical deterrents. Carriers were installed in forests and fed to deer. The first experiment was to find suitable sites and installation methods for carriers. Criteria for the local suitability and the installation methods were as follows: a) Sites where deer are active should be selected; b) Carriers should be installed along actively used deer trails; c) Installation sites of carriers should be changed in response to deer movement; d) Carriers should be produced from tree species that deer naturally prefer; and e) Each carrier should be partially buried in the snow. The second experiment evaluated the feasibility of a cafeteria test method based on the results of the first experiment. The method was used for 13 sets of the cafeteria test, in which the deterrent effectiveness of 5 chemicals (wood tar, rosin, wood vinegar, and 2 pyroligneous liquors) was examined. We obtained results from all the sets. The chemicals tested did not deter bark stripping by deer. Nevertheless, the method used in the present study was practical for the cafeteria tests.     

Effects of local and regional landscape characteristics on wildlife distribution across managed forests

Understanding the impacts of local and regional landscape characteristics on spatial distributions of wildlife species is vital for achieving ecological and economic sustainability of forested landscapes. This understanding is important because wildlife species such as white-tailed deer (Odocoileus virginianus) have the potential to affect forest dynamics differently across space. Here, we quantify the effects of local and regional landscape characteristics on the spatial distribution of white-tailed deer, produce maps of estimated deer density using these quantified relationships, provide measures of uncertainty for these maps to aid interpretation, and show how this information can be used to guide co-management of deer and forests. Specifically, we use ordinary least squares and Bayesian regression methods to model the spatial distribution of white-tailed deer in northern hardwood stands during the winter in the managed hardwood-conifer forests of the central Upper Peninsula of Michigan, USA. Our results show that deer density is higher nearer lowland conifer stands and in areas where northern hardwood trees have small mean diameter-at-breast-height. Other factors related with deer density include mean northern hardwood basal area (negative relationship), proportion of lowland conifer forest cover (positive relationship), and mean daily snow depth (negative relationship). The modeling methods we present provide a means to identify locations in forest landscapes where wildlife and forest managers may most effectively co-ordinate their actions.     

Erosive phenomenon in heavy snow mountainous regions in Japan

This paper reviews the studies conducted in Japan on the erosion caused by snow cover movement and presents erosion control measures and future visions about forest management in heavy snow regions. Japan is one of the heaviest snowfall countries in the world, more than half of whose land is situated in heavy snow regions. In addition, a large part of this country has steep mountain sites. Because of these geographical features, erosion is frequently caused by snow cover movement on mountain slopes and a lot of research on this phenomenon has been conducted. Snow-induced erosion is generated at forest fire sites, deforestation sites, and plantations by stumps uprooting, pulled-out bushes, and topsoil movement induced by snow cover movement. Due to its occurrence mechanism, the depth of the erosion is very shallow, 60 cm or less. The erosion area ranges from less than 10 m² to several hectares. In general, the number of small erosions, less than 100 m², is very large. The geomorphic features that generate snow-induced erosion almost always correspond to those of avalanche slopes. As for geological characteristics, snow-induced erosion is found in the Neogene area or older. The environment surrounding the snow-induced erosion sites is very harsh, so development of reforestation technology is still in the trial-and-error stage. In order to prevent additional devastation in heavy snow regions, clarification of slope erosive phenomenon from the aspect of slope stability under the snow cover, and progress in the research for establishment of diverse management of forest are required. Recipient of the Japanese Forestry Society Award 1998.     

Habitat use of large ungulates in northeastern Germany in relation to forest management

Estimating large herbivore density has been a major area of research in recent decades. Previous studies monitoring ungulate density, however, focused mostly on determining animal abundance, and did not interpret animal distribution in relation to habitat parameters. We surveyed large ungulates in the Biodiversity Exploratory Schorfheide-Chorin using faecal pellet group counts. This allowed us to explore the link between relative ungulate abundance, habitat use, and browsing damage on trees in a region with several types of forest, including unharvested and age-class beech forests, as well as age-class pine forests. Our results demonstrate that roe deer and fallow deer relative abundance is negatively correlated with large tree cover, and positively correlated with the cover of small shrubs (Rubus spec., Vaccinium spec.), and winter food supply. Habitat use of roe deer and fallow deer, as estimated by counting faecal pellet groups, revealed a preference for mature pine forests, and avoidance of deciduous forests. This differential habitat use is explained by different distributions of high quality food resources during winter. The response of deer to understory cover differed between roe deer and fallow deer at high cover percentages. The amount of browsing damage we observed on coniferous trees was not consistent with the relative deer abundance. Browsing damage was consistently higher on most deciduous trees, except for beech saplings which sustained less damage when roe deer density was low. Because roe deer is a highly selective feeder, it was reported to affect tree diversity by feeding only on trees with high nutritional value. Consequently, we propose that managing the number of all deer species by hunting is necessary to allow successful forest regeneration. Such an adjustment to deer numbers would need to account for both current tree diversity and alternative food resources. Our findings may be applicable to other forest landscapes in northeastern Germany including mature pine stands and differently harvested deciduous forests.     

Among-year variation in deer population density index estimated from road count surveys

A method for obtaining a relative deer population density index with low cost and effort is urgently needed in wildlife protection areas that need their own deer management guidelines. We recorded the number of deer sighted during our daily trips on forest roads by car in Ashiu Forest at Kyoto University, Japan, beginning in 2006. We used generalized additive mixed models (GAMMs) to estimate among-year trends in the number of deer sighted. We applied models for the total number of deer (TND), number of adults (NA), and number of fawns (NF) sighted, which included both current-year and 1-year-old fawns. Full models included the terms of year (2007, 2008, 2009, and 2010), weather (fine, cloudy, and rain/snow), and nonlinear effects of season (date) and time (time). The optimal GAMMs for TND, NA, and NF did not include the effect of weather but included those of time, date, and year. The detected among-year trends in deer population may be influenced by differences in snow environments among the years. The modeling of road count data using GAMM quantitatively determined among-year variation in the number of deer sighted. This trend was similar to that of the population density estimated using a block count survey conducted in Ashiu Forest.     

韩国原麝分布区50年间的变迁

在南朝鲜于1999年的2月至12月间,根据有关文献,调查问卷和对原麝的种类,粪便,及其在有雪和无雪的季节里的野外踪迹的调查,作者概述了50年中原麝的数量和分布区的变化。结果表明:从50年代至1999间,原麝(Moschus moschiferus parvipes)的分布区呈明显缩减之势。由于在原麝分布区中大规模地进行公路及林道的建设,导致了其生境片断化和丢失。而且牟取利润的非法猎捕也是造成原麝的种群数量和分布区缩减的主要原因,在高海拔地区的林道也常被盗猎者所利用。为保护韩国原麝资源,急待严格禁止非法猎捕行为。原麝生活习性方面的研究,为合理的保护和管理原麝提供了重要的基础信息。图1参9。     

Regeneration of Pinus sylvestris in a natural pinewood in NE Scotland following reduction in grazing by Cervus elaphus

The occurrence of Scots pine (Pinus sylvestris L.) seedlings and saplings (<2.0 m in height and suppressed by grazing) and ground characteristics were recorded in a 300 ha block of natural pine forest in 1993. The density of red deer (Cervus elaphus L.) was then reduced by exclosure to approximately 3–4 deer km⁻², which is below the threshold at which pine regeneration should occur. Numbers and performance of pine seedlings and saplings were further monitored 2 and 4 years after exclosure. Numbers of young pine increased over time. In the three years with observations 97–99% of pine seedlings and saplings were recorded within 20 m of a seed source. Stepwise multiple regression was used to explore the relationships of pine establishment with plot characteristics for (a) all observation plots (n = 178) and (b) plots within 20 m of a seed source (n = 154). The factors most closely related to the number of pine seedlings and saplings in 1997 were, for (a), seed–source distance, vegetation height, blaeberry cover, slope and deer pellet-group density in 1993, all but the last having negative effects. For (b), vegetation height, blaeberry cover and slope were again selected predictors, and again had negative effects. Possible mechanisms by which the selected main effects may influence pine regeneration are discussed, the positive relationship to deer density being considered to reflect the creation of gaps in the sward suitable for germination. However, the amounts of variation explained in the models were low, being 16% for (a) and 13% for (b), reflecting the patchy nature and diverse age of the regeneration.     

Impact of snow cover on photoinhibition and winter dessication in evergreen Rhododendron ferrugineum leaves during subalpine winter

Effects of winter snow cover on photoinhibition and possible interactions with winter desiccation were investigated in situ in an evergreen subalpine woody species, Rhododendron ferrugineum L., at the alpine timberline (1950 m a.s.l.). Timing and duration of complete snow cover markedly influenced potential efficiency of photosystem II (PSII; F(v) /F(m)). Lack of snow cover led to severe but mostly reversible photoinhibition with F(v)/F(m) values as low as 0.05. Complete snow cover immediately stopped further reductions in PSII efficiency. Snow cover promoted recovery from photoinhibition, but only if, in addition to shading by snow, plants were exposed to nonfreezing temperatures close to 0 degrees C. The F(v)/F(m) ratio was closely related to minimum leaf temperatures because both photoinhibition and recovery from photoinhibition were strongly influenced by temperature. The period without major reductions in PSII efficiency lasted for only two months, reflecting the extremely short growing period in the subalpine environment. Compared with complete snow cover, incomplete snow cover led to significantly higher water losses as well as lower dehydration tolerance, because both osmotic adjustment and changes in turgor maintenance capacity were significantly reduced. Interactions between photoinhibition and winter desiccation were masked by the direct effects of freezing temperatures. However, both photoinhibition and winter desiccation are closely linked and occur together under field conditions in this evergreen subalpine woody species.     

基于MaxEnt模型的白水河国家级保护区有蹄类保护动物生境适宜性评价

通过MaxEnt模型对白水河国家级自然保护区4种有蹄类保护物种进行生境适宜性评价,研究结果如下:(1)20次重复后斑羚、鬣羚、林麝、羚牛的训练集AUC值分别为0.962、0.947、0.924和0.945;(2)斑羚、鬣羚、林麝、羚牛得适宜栖息地分别占保护区总面积的14%、27%、25%、24%,次适宜栖息地占保护区总面积的27%、19%、35%、34%,不适宜栖息地占保护区总面积59%、54%、40%、42%;(3)对斑羚贡献最大的3个环境因子是坡向、坡度和落叶灌丛,对鬣羚贡献最大的3个环境因子是竹林、栽培竹林和落叶灌丛,对林麝贡献最大的3个环境因子是坡向、落叶灌丛和竹林,对羚牛贡献最大的3个环境因子是坡向、竹林以及落叶阔叶林。     

雪盖对兴安鹿蹄草叶片叶绿素与花青素含量影响

运用分光光度法测定了兴安鹿蹄草在雪盖前期、雪盖期及雪盖后期的叶绿素和花青素含量变化,结果表明：在雪盖前期,从10月初到11月中旬,叶绿素、花青素含量、叶绿素a与叶绿素b比值随着气温的降低而增高,但叶绿素与花青素比值随气温降低而降低;雪被覆盖期,从12月初到翌年3月初,由于被积雪覆盖,叶绿素含量低于雪盖前期,叶绿素a与叶绿素b比值明显增高。花青素含量从12月中旬开始降低,叶绿素与花青素比值降到最低值;雪盖后期,3月初至3月中旬,叶绿素含量高于雪被覆盖期,4月初有所下降,之后又回升,叶绿素a与叶绿素b比值明显低于雪被覆盖期,花青素含量从3月中旬开始明显下降,4月初又开始升高。叶绿素与花青素比值明显高于雪被覆盖期。     

What factors affect national-scale deer population dynamics in the Republic of Ireland?

Research into deer population dynamics has mostly focused on community or landscape scales in the Republic of Ireland. However, in order to propose national deer management strategies to confront the increasing deer populations in recent years, a larger scale analysis of deer populations is necessary. In this inter-county, national study, generalised linear mixed models were utilised to examine the relationship between the harvest rate (defined as the numbers harvested per 100?ha in this study) data and factors identified in past research as contributing to deer population dynamics on a county basis, where annual county-level deer harvest records were used to reflect deer populations by species. The procedures were repeated for each species and significant factors and their impacts were identified for each county. The results suggested that multiple factors affect deer population dynamics; for instance, increases in forest cover tended to result in increases in deer populations of all species, and the presence of red and sika deer populations in a county had a positive influence on hybrid deer populations. National migration maps for each deer species were produced, as well as predictions of future population trends. The outcome of this study can be used to guide the development of a national deer management strategy and the prioritisation, on a regional basis, of deer control measures.     

大兴安岭林区雪兔冬季生境选择研究

在冬季,雪兔在非生物环境因子的选择中,偏好山体的坡下位和谷底,坡向为阳坡,坡度较小及小于10 cm雪深的生境;在生物环境因子的选择中,偏好针阔混交林和灌丛、乔木株数较少、灌木低于2 m、灌丛隐蔽度为30%-60%、杂草高度小于50 cm和含有倒木的生境;冬季雪兔对生境选择是基于保存自身能量、获取食物和躲避天敌基础上的。     

Effects of sika deer (Cervus nippon) and dwarf bamboo (Sasamorpha borealis) on seedling emergence and survival in cool-temperate mixed forests in the Kyushu Mountains

Effects of sika deer (Cervus nippon) and dwarf bamboo (“sasa;” Sasamorpha borealis) on seedling emergence and survival were investigated in cool-temperate mixed forests in the Kyushu mountain range, Japan. We compared the effects of sika deer between two sites with different sika deer densities. One site (no-sasa forest) has sparse cover of S. borealis and a high density of sika deer, and the other site (sasa forest) has dense cover of S. borealis with a low density of sika deer. In the no-sasa forest, more seedlings emerged and the survival rate of the seedlings was higher compared with the sasa forest. Compared with the sasa forest, the canopy in the no-sasa forest was more open, the organic layer was shallower and drier, the mean daily soil temperature was higher, and soil temperature fluctuated more widely. Those environmental parameters did not differ between unfenced and fenced plots. The comparison between the sasa and no-sasa forests suggested that removal of S. borealis by sika deer had an indirect positive effect on seedling emergence and survival. However, the fenced-plot experiments indicated that sika deer inhibited seedling emergence and survival. These contradictory conclusions could result from the much larger negative effects of S. borealis on seedling emergence and survival compared with the effects of sika deer browsing.     

气象因子对秦岭大熊猫季节性垂直迁徙等活动的影响

大熊猫(Ailuropoda melanoleuca)是我国独有的珍稀濒危物种,其因适应竹子资源的季节变化而进行垂直迁徙,关于其迁徙模式和影响迁徙的因子目前还不甚明确。为了探究影响大熊猫垂直迁徙的因子,于2013年10月至2014年9月,在陕西省佛坪国家级自然保护区三官庙设立了9条样线,共布设52台红外相机对大熊猫的垂直迁徙时间进行研究;同时,结合气象监测数据探究气温、降雨量、湿度和积雪覆盖等因子对大熊猫迁徙活动的影响。研究结果表明,大熊猫垂直空间分布季节性差异明显,7月主要在高海拔秦岭箭竹分布区活动,而2月则主要在低海拔巴山木竹分布区活动。大熊猫从冬居地向夏居地迁徙迅速,仅1~3d即可完成,而从夏居地向冬居地迁徙经历时间较长。气温、积雪覆盖、湿度和降雨量等因素都会对大熊猫的迁徙活动产生影响,大熊猫喜欢选择在“最适温度”区域活动,当高海拔区域出现积雪覆盖时,就会迁徙到低海拔活动。湿度和降雨量主要通过控制竹子发笋和生长来影响大熊猫的迁徙。研究证实了大熊猫的垂直迁徙现象,并获得了关于大熊猫迁徙模式和影响因子相关的较为详细的基础数据,为野生大熊猫的保护提供理论依据。     

Effects of white-tailed deer on vegetation structure and woody seedling composition in three forest types on the Piedmont Plateau

White-tailed deer (Ododcoileus virginiana) can substantially affect the structure and species composition of a forest. The tolerance of a forest community to browsing may vary by type as a result of varying biotic and abiotic factors of the environment. To date, no studies have compared the effects of browsing among forest communities within a physiographic region. We investigated the effects of browsing on vegetation structure and woody seedling composition in three forest types (oak–hickory, Virginia pine–eastern red cedar, bottomland hardwood) in Manassas National Battlefield Park (MNBP), Virginia, USA. We compared forb cover, vertical plant cover (0–1.5 m tall), and survival of tagged seedlings in 10 exclosed (2 m × 6 m) and 10 unexclosed plots in each forest type during a 5-year period. No differential effects of browsing were found among forest types. In all forest types, deer (67 deer/km²) suppressed forb and vertical plant cover to levels less than would be expected in the absence of deer. Seedling survival rates of most species were significantly reduced by browsing. By the 4th year of the study, box elder (Acer negundo), hickory (Carya spp.), and red maple (Acer rubrum) had been eliminated from unexclosed plots, and red and white oaks (Quercus spp.) dramatically reduced. Ash (Fraxinus spp.), black cherry (Prunus serotina), and hackberry (Celtis occidentalis), although significantly impacted, remained the most abundant species throughout the study. These findings suggest that white-tailed deer may be modifying the structure of the forest interior to the extent that it adversely affects wildlife species dependent on a dense understory to thrive. We predict that the future composition of forests in MNBP will shift towards stands with fewer species and a greater dominance of ash, black cherry, and hackberry, particularly in the oak–hickory and bottomland hardwood forests, where the majority of current dominants are most affected.     

一种安装在三轮车上可拆卸的扫雪装置设计

安装在三轮车上的可拆卸扫雪装置具有便携、高效、环保、节能等特点.该设计使三轮车同时具备了扫雪和装载的功能,扫雪时可采用电机和人力双驱,承载时可由人力单驱.计算了工作状态下扫雪轮的转速以及积雪所受的离心力,并对工作转速进行了校核.通过求解行车功率和除雪总功率估算出电机的额定功率.该装置操作方便,实用性强,有一定的推广价值.     

Of forest,snow and lichen: Sámi reindeer herders’ knowledge of winter pastures in northern Sweden

Over the last few decades, the use of forests both by Sámi reindeer herders and for commercial forestry has been a source of increasing conflict in northern Sweden. Forestry disturbs forest ecosystems and thus damages reindeer pastures, especially those rich in ground lichen, for which reindeer forage during the wintertime by digging through the snow. Despite increased communication between the two groups, the Sámi still feel that their interests are not adequately considered by the commercial forestry sector. This paper presents the results of an interdisciplinary study that comprised semi-directed interviews and participant observations. The objective was to understand the Sámi reindeer herders’ extensive ecological knowledge of winter forest pastures, and the characteristics they observe when managing this resource. The study also analysed specific terminology used by the Sámi herders, to describe, analyse and communicate these properties. These terms, as well as Sámi herder knowledge in general, emphasize the importance of snow cover for reindeer grazing in forest pastures, as well as the effects of forest structure and ground vegetation on variations in snow cover during the winter. Whereas the Western use of the word ‘pasture’ is often associated with a specific plant community, the Sámi herders’ understanding of the word also includes the effect of snow on grazing and for this they use a culturally specific word in their language: guohtun. This term conveys the additional notion of whether it is possible for reindeer to access the pasture under the snow. Sámi herder knowledge and know-how allow them to use the mosaic of forest ecosystems to accommodate variability in snow cover during the wintertime, using different forest areas in response to different grazing conditions. Finally, the authors argue that, in order to promote the balanced, multiple use of boreal forest ecosystems, it is necessary to acknowledge and understand Sámi reindeer herders knowledge and thus to fully integrate their needs and aspirations.     

Will changes in root-zone temperature in boreal spring affect recovery of photosynthesis in Picea mariana and Populus tremuloides in a future climate?

Future climate will alter the soil cover of mosses and snow depths in the boreal forests of eastern Canada. In field manipulation experiments, we assessed the effects of varying moss and snow depths on the physiology of black spruce (Picea -mariana (Mill.) B.S.P.) and trembling aspen (Populus tremuloides Michx.) in the boreal black spruce forest of western Québec. For 1 year, naturally regenerated 10-year-old spruce and aspen were grown with one of the following treatments: additional N fertilization, addition of sphagnum moss cover, removal of mosses, delayed soil thawing through snow and hay addition, or accelerated soil thawing through springtime snow removal. Treatments that involved the addition of insulating moss or snow in the spring caused lower soil temperature, while removing moss and snow in the spring caused elevated soil temperature and thus had a warming effect. Soil warming treatments were associated with greater temperature variability. Additional soil cover, whether moss or snow, increased the rate of photosynthetic recovery in the spring. Moss and snow removal, on the other hand, had the opposite effect and lowered photosynthetic activity, especially in spruce. Maximal electron transport rate (ETR(max)) was, for spruce, 39.5% lower after moss removal than with moss addition, and 16.3% lower with accelerated thawing than with delayed thawing. Impaired photosynthetic recovery in the absence of insulating moss or snow covers was associated with lower foliar N concentrations. Both species were affected in that way, but trembling aspen generally reacted less strongly to all treatments. Our results indicate that a clear negative response of black spruce to changes in root-zone temperature should be anticipated in a future climate. Reduced moss cover and snow depth could adversely affect the photosynthetic capacities of black spruce, while having only minor effects on trembling aspen.