scholarly journals Foraging behaviour of snowshoe hares (Lepus americanus) in conifer forests regenerating after fire

2019 ◽  
Vol 97 (5) ◽  
pp. 446-452 ◽  
Author(s):  
J. Hutchen ◽  
K.E. Hodges
Keyword(s):  
Pinus Contorta ◽  
Foraging Behaviour ◽  
Tree Regeneration ◽  
Lepus Americanus ◽  
Conifer Forests ◽  
Cover Type ◽  
Heterogeneous Landscapes ◽  
Snowshoe Hares ◽  
Winter Foraging ◽  
Dense Tree

Wildfires in conifer forests create patchy, heterogeneous landscapes. For many animal species, this post-fire variability means having to navigate quite different habitat patches to locate adequate cover and food. For snowshoe hares (Lepus americanus Erxleben, 1777), post-fire landscapes could include risky open patches, as well as dense regenerating stands rich in food and cover. We analyzed snowshoe hare tortuosity, speed of movement, and amount of browse along winter foraging pathways in unburned mature forest and in dense regenerating stands or open areas with sparse regeneration 12–13 years after the Okanagan Mountain Park fire (>25 000 ha near Kelowna, British Columbia, Canada) to determine whether hares change foraging behaviour in relation to cover type. Hares moved the fastest and browsed the least in open habitats. Hares browsed most often in areas where sapling regeneration was dense; their main forage was lodgepole pine (Pinus contorta Douglas ex Loudon). No differences were found in pathway tortuosity in relation to cover type (open, regenerating, or mature patches). When hares moved slower along foraging pathways, they also moved slightly more tortuously and ate more. These results suggest that hares prefer post-fire areas with dense tree regeneration.

Influence of repeated fertilization on forest ecosystems: relative habitat use by snowshoe hares (Lepus americanus)

2006 ◽  
Vol 36 (9) ◽  
pp. 2080-2089 ◽  
Author(s):  
Thomas P Sullivan ◽  
Druscilla S Sullivan ◽  
Pontus MF Lindgren ◽  
Douglas B Ransome
Keyword(s):  
Habitat Use ◽  
Pinus Contorta ◽  
Large Scale ◽  
Lodgepole Pine ◽  
Structural Diversity ◽  
Lepus Americanus ◽  
Volume Index ◽  
South Central ◽  
Crown Volume ◽  
Snowshoe Hares

This study was designed to test the hypothesis that large-scale precommercial thinning (PCT) and repeated fertilization of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) would enhance relative habitat use by snowshoe hares (Lepus americanus Erxleben) in managed stands. Study areas were located near Summerland, Kelowna, and Williams Lake in south-central British Columbia, Canada. Each study area had nine treatments: four pairs of stands thinned to densities of 250, 500, 1000, and 2000 stems/ha, with one stand of each pair fertilized five times at 2-year intervals, and an unthinned stand. Understory vegetation and relative habitat use by snowshoe hares were measured annually from 1999 to 2003, 6–10 years after the onset of treatments. Mean crown volume index of herbs was significantly higher in fertilized than unfertilized stands, but density had no effect. Shrub volume was not affected by either treatment. Mean crown volume index of trees was significantly greater in the fertilized and high-density stands. Mean total richness of vascular plants was significantly reduced by fertilization. Mean total structural diversity of vegetation was highest in the low-density stands but was not affected by fertilization. Relative habitat use by hares, based on fecal pellet counts, was highest in the 2000 stems/ha and unthinned stands in summer. This pattern also occurred in winter when hare use was higher in fertilized than unfertilized stands. Overall, fertilized 2000 stems/ha stands provided habitat for hares to a degree comparable with unthinned stands of lodgepole pine.

Dynamics of a snow shoe hare population in fragmented habitat

1993 ◽  
Vol 71 (7) ◽  
pp. 1385-1392 ◽  
Author(s):  
Lloyd B. Keith ◽  
Sara E. M. Bloomer ◽  
Tomas Willebrand
Keyword(s):  
Patch Size ◽  
Canis Latrans ◽  
Lepus Americanus ◽  
Fragmented Habitat ◽  
Proximate Cause ◽  
Lower Survival ◽  
The Third ◽  
Snowshoe Hares ◽  
Poorly Drained Soils ◽  
Hare Population

During November 1988 – December 1991 we livetrapped, radio-collared, and monitored the survival, reproduction, and movements of snowshoe hares (Lepus americanus) in highly fragmented habitat near the species' geographic limit in central Wisconsin. Our 7 study areas centered on 5- to 28-ha patches of prime habitat: dense stands of willow (Salix), alder (Alnus), and regenerating aspen (Populus) on poorly drained soils. Maximum hare densities averaged 1.6 – 0.8/ha, and were unrelated to patch size. Rapid declines to extinction occurred on 3 of the 5 smallest study areas; on another, where extinction seemed imminent, juvenile ingress restored the population. On the 2 largest areas (23 – 28 ha of prime habitat) hare populations were stationary during the first 2 years, but declined by 50 – 70% in the third as mean annual (September – August) survival of radio-collared hares fell from 0.27 (1988 – 1990) to 0.07 (1990 – 1991). Annual survival on the 3 extinction sites averaged just 0.015 compared with 0.179 elsewhere. Reproduction did not differ between small (5 – 7 ha) vs. larger (23 – 28 ha) patches nor between years. Estimated dispersal of adult and juvenile hares from the 5 small study areas was twice as high as from the 2 larger, viz. 16 vs. 35% annually. Dispersers appeared to have markedly lower survival. Predation, chiefly by coyotes (Canis latrans), was the proximate cause of 96% (117 of 122) of natural deaths among radio-collared hares, and was therefore the overwhelming determinant of survival and thus population trend. Results of this study suggest that probabilities of extinction in such fragmented habitat depend importantly on patch size and attendant hare numbers; i.e., fall populations of < 10 hares frequenting patches of prime habitat ≤ 5 ha are not likely to persist long without ingress.

scholarly journals Potentials of Natural Tree Regeneration after Clearcutting in Subalpine Forests

2008 ◽  
Vol 23 (1) ◽  
pp. 46-52 ◽  
Author(s):  
Juergen Kreyling ◽  
Andreas Schmiedinger ◽  
Ellen Macdonald ◽  
Carl Beiekuhnlein
Keyword(s):  
Natural Regeneration ◽  
Pinus Contorta ◽  
Woody Debris ◽  
Negative Relationship ◽  
Forest Edge ◽  
Tree Regeneration ◽  
Tree Seedlings ◽  
Tree Seedling ◽  
Engelmann Spruce ◽  
Understory Plant

Abstract Regeneration of interior mountain forests still is not adequately understood, although these forests are subject to intensified use over the last decades. We examined factors influencing the success of natural tree regeneration after harvesting in the Engelmann spruce–subalpine fir zone of the Monashee Mountains, British Columbia, Canada. Distance from the forest edge was an important factor for regeneration; at distances exceeding 70 m from the forest edge only 50% of plots showed sufficient natural regeneration to meet stocking targets compared with 90% of plots closer to forest edges. Seedling density and growth were superior in the more protected southern portions of clearcuts. Seedling growth was less in plots containing high cover of downed woody debris. There was no relationship between understory plant diversity or composition and tree seedling regeneration. However, cover of fireweed (Epilobium angustifolium) had a significant negative relationship with density but not growth of tree seedlings, particularly for lodgepole pine (Pinus contorta var. latifolia). Cover of fireweed decline substantially within the first 10 years after clearcutting. We conclude that natural regeneration of trees has potential to help achieve stocking targets and also to maintain natural diversity of tree species if spatial constraints, especially thresholds in clearcut size, are considered.

scholarly journals Variability in Mixed Conifer Spatial Structure Changes Understory Light Environments

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 1015 ◽  
Author(s):  
Jeffery B. Cannon ◽  
Wade T. Tinkham ◽  
Ryan K. DeAngelis ◽  
Edward M. Hill ◽  
Mike A. Battaglia
Keyword(s):  
Spatial Patterns ◽  
Ponderosa Pine ◽  
Spatial Scales ◽  
Light Availability ◽  
Structural Complexity ◽  
Tree Regeneration ◽  
Conifer Forests ◽  
Mixed Conifer ◽  
Regeneration Dynamics ◽  
Wide Range

In fire-adapted conifer forests of the Western U.S., changing land use has led to increased forest densities and fuel conditions partly responsible for increasing the extent of high-severity wildfires in the region. In response, land managers often use mechanical thinning treatments to reduce fuels and increase overstory structural complexity, which can help improve stand resilience and restore complex spatial patterns that once characterized these stands. The outcomes of these treatments can vary greatly, resulting in a large gradient in aggregation of residual overstory trees. However, there is limited information on how a range of spatial outcomes from restoration treatments can influence structural complexity and tree regeneration dynamics in mixed conifer stands. In this study, we model understory light levels across a range of forest density in a stem-mapped dry mixed conifer forest and apply this model to simulated stem maps that are similar in residual basal area yet vary in degree of spatial complexity. We found that light availability was best modeled by residual stand density index and that consideration of forest structure at multiple spatial scales is important for predicting light availability. Second, we found that restoration treatments differing in spatial pattern may differ markedly in their achievement of objectives such as density reduction, maintenance of horizontal and tree size complexity, and creation of microsite conditions favorable to shade-intolerant species, with several notable tradeoffs. These conditions in turn have cascading effects on regeneration dynamics, treatment longevity, fire behavior, and resilience to disturbances. In our study, treatments with high aggregation of residual trees best balanced multiple objectives typically used in ponderosa pine and dry mixed conifer forests. Simulation studies that consider a wide range of possible spatial patterns can complement field studies and provide predictions of the impacts of mechanical treatments on a large range of potential ecological effects.

Long-term responses of mammalian herbivores to stand thinning and fertilization in young lodgepole pine (Pinus contorta var. latifolia) forest

2010 ◽  
Vol 40 (12) ◽  
pp. 2302-2312 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Druscilla S. Sullivan ◽  
Pontus M.F. Lindgren ◽  
Douglas B. Ransome
Keyword(s):  
Habitat Use ◽  
Pinus Contorta ◽  
Large Scale ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
South Central ◽  
Commercial Thinning ◽  
Snowshoe Hares ◽  
Understory Shrubs

Snowshoe hares (Lepus americanus Exrleben, 1777), mule deer (Odocoileus hemionus (Rafinesque, 1817)), and moose (Alces alces (L., 1758)) commonly occur in young coniferous forests. This study was designed to test the hypothesis that large-scale pre-commercial thinning (PCT) and repeated fertilization 15–20 years after the onset of treatments in young lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Wats.) stands would enhance relative habitat use by hares, deer, and moose compared with unmanaged stands. Study areas were located in south-central British Columbia, Canada. Habitat use was measured by fecal pellet and pellet-group counts. Understory vegetation and coniferous stand structure were measured in all stands. Habitat use by deer and moose was highest in heavily thinned stands, probably due to the higher levels of forage and cover provided by understory shrubs and conifers in thinned stands. Habitat use by snowshoe hares was highest in high-density stands, but also in lower-density (≤1000 stems·ha–1) stands where an increase in understory conifers provided essential cover for hares. Managers should consider the long-term nature of understory development in young stands managed for timber production. Heavy thinning (≤1000 stems·ha–1) will generate suitable understory habitat for these herbivores sooner than conventional PCT at higher stand densities.

Seasonal Metabolic Acclimatization in a Northern Population of Free-Ranging Snowshoe Hares,Lepus americanus

2009 ◽  
Vol 90 (3) ◽  
pp. 761-767 ◽  
Author(s):  
Michael J. Sheriff ◽  
Louise Kuchel ◽  
Stan Boutin ◽  
Murray M. Humphries
Keyword(s):  
Lepus Americanus ◽  
Northern Population ◽  
Snowshoe Hares ◽  
Free Ranging

Survival of juvenile hares during a cyclic population increase

1998 ◽  
Vol 76 (10) ◽  
pp. 1949-1956 ◽  
Author(s):  
Elizabeth A Gillis
Keyword(s):  
Cause Of Death ◽  
Food Availability ◽  
Survival Rates ◽  
Lepus Americanus ◽  
Population Increase ◽  
Differential Survival ◽  
Proximate Cause ◽  
Supplemental Food ◽  
Snowshoe Hares ◽  
And Control

Snowshoe hares (Lepus americanus) are multilittered synchronous breeders that produce up to four distinct litters of young each summer. I used radiotelemetry to determine the effects of juvenile cohort (i.e., litter group) and food availability on postweaning survival of hares in the southwestern Yukon during the increase phase of a hare cycle. During the study, I monitored 86 juvenile hares from control areas and areas in which supplemental food was provided. Twenty-eight-day survival did not differ between food addition and control areas for any juvenile cohort, and survival rates of juveniles (all cohorts combined) did not differ significantly from those of adults (juveniles: 0.91 per 28 days; adults: 0.93 per 28 days). However, when examined by juvenile cohort, survival of third and fourth litters was significantly lower than that of adults and first and second litters. These differences were the result of differential survival among the juvenile cohorts during a 3-month period in the fall (September-November). Predation was the primary proximate cause of death for weaned juvenile hares, accounting for 86% of deaths.

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