Interaction among deer browsing, hunting, and tree regeneration

2002 ◽  
Vol 32 (7) ◽  
pp. 1254-1264 ◽  
Author(s):  
Jean-Louis Martin ◽  
Christophe Baltzinger

The intentional removal or addition of species or specific human impacts on ecosystems trigger changes that can help us understand species interactions. In many temperate forests, deer populations are increasing and so is the need to understand how they influence ecosystems. We took advantage of the introduction of Sitka black-tailed deer (Odocoileus hemionus sitchensis Merriam) to the Queen Charlotte Islands (Haida Gwaii), British Columbia, Canada, to study how hunting pressure affects the impact of deer on tree regeneration after logging. We show that although the regeneration of western redcedar (Thuja plicata Donn ex D. Don) is drastically reduced in presence of deer, regeneration is better and browsing stress lower, in areas where deer are more exposed to hunting. Similar effects of accessibility for hunters are observed on browsing stress of Sitka spruce (Picea sitchensis (Bong.) Carrière). Western hemlock (Tsuga heterophylla (Raf.) Sarg.) is not significantly affected, and its regeneration is not correlated to hunting. We suggest that the effect of hunting on tree regeneration could be explained by the incidence of hunting on deer behaviour rather than by the actual number of deer killed by hunters. These results suggest that the future occurrence of redcedar stands in second-growth forests on this archipelago may depend on the amount and distribution of deer hunting.

1984 ◽  
Vol 62 (7) ◽  
pp. 1561-1563
Author(s):  
R. T. Ogilvie ◽  
R. J. Hebda ◽  
Hans L. Roemer

The occurrence of Oxalis oregana Nutt. in British Columbia is documented for five localities on the west coast of Vancouver Island and one locality in the Queen Charlotte Islands. The Oxalis populations grow in alluvial Tsuga heterophylla – Picea sitchensis – Thuja plicata – Polystichum munitum forest communities. Rhizomatous reproduction was recorded in all populations and flowering in two of the Vancouver Island populations. Three of the populations may be less than 3000 years old because they would have been inundated by higher sea levels during the middle Holocene. Possible introduction of plants by native people from the Olympic Peninsula, WA, is discussed.


2001 ◽  
Vol 79 (4) ◽  
pp. 389-397 ◽  
Author(s):  
Hugh J Barclay

Leaf angle distributions are important in assessing both the flexibility of a plant's response to differing daily and seasonal sun angles and also the variability in the proportion of total leaf area visible in remotely sensed images. Leaf angle distributions are presented for six conifer species, Abies grandis (Dougl. ex D. Don) Lindl., Thuja plicata Donn. ex D. Don, Tsuga heterophylla (Raf.) Sarg., Pseudotsuga menziesii (Mirb.) Franco, Picea sitchensis (Bong.) Carr. and Pinus contorta Dougl. ex Loud. var. latifolia. The leaf angles were calculated by measuring four foliar quantities, and then the distributions of leaf angles are cast in three forms: distributions of (i) the angle of the long axis of the leaf from the vertical for the range 0–180°; (ii) the angle of the long axis of the leaf for the range 0–90°; and (iii) the angle of the plane of the leaf for the range 0–90°. Each of these are fit to the ellipsoidal distribution to test the hypothesis that leaf angles in conifers are sufficiently random to fit the ellipsoidal distribution. The fit was generally better for planar angles and for longitudinal angles between 0° and 90° than for longitudinal angles between 0° and 180°. The fit was also better for Tsuga heterophylla, Pseudotsuga menziesii, Picea sitchensis, and Pinus contorta than for Abies grandis and Thuja plicata. This is probably because Abies and Thuja are more shade tolerant than the other species, and so the leaves in Abies and Thuja are preferentially oriented near the horizontal and are much less random than for the other species. Comparisons of distributions on individual twigs, whole branches, entire trees, and groups of trees were done to test the hypothesis that angle distributions will depend on scale, and these comparisons indicated that the apparent randomness and goodness-of-fit increased on passing to each larger unit (twigs up to groups of trees).Key words: conifer, leaf angles, ellipsoidal distribution.


1993 ◽  
Vol 8 (2) ◽  
pp. 67-70 ◽  
Author(s):  
E. E. Nelson ◽  
Rona N. Sturrock

Abstract Several species of conifers were outplanted around infected stumps in Oregon and British Columbia to measure their susceptibility to laminated root rot caused by Phellinus weirii. Grand fir (Abies grandis) experienced nearly 30% mortality caused by P. weirii. Douglas-fir (Pseudotsuga menziesii) mortality exceeded 20%. Noble fir (A. procera), Sitka spruce (Picea sitchensis), giant sequoia (Sequoiadendron giganteum), western hemlock (Tsuga heterophylla), and ponderosa pine (Pinus ponderosa) mortality averaged less than 10%. Western white pine (P. monticola) and lodgepole pine (P. contorta) mortality was less than 1%. Phellinus weirii did not cause mortality of western redcedar (Thuja plicata) or redwood (Sequoia sempervirens). Apparent susceptibility, based on mortality over 17-20 growing seasons, was similar to that recorded in past field observations. West. J. Appl. For. 8(2):67-70.


2003 ◽  
Vol 18 (4) ◽  
pp. 250-258
Author(s):  
Steve Bowers

Abstract This study documented and field-tested a simplified version of the Westside Grading Guidelines as published in the Official Rules Handbook by the Northwest Log Rules Advisory Group. A four-step dichotomous key was documented and field-tested to determine merchantable vs. nonmerchantable logs. The study also documented and field-tested an individual seven-step dichotomous log grading key for evaluating second-growth Douglas-fir (Pseudotsuga menziesii), Sitka spruce (Picea sitchensis), western hemlock (Tsuga heterophylla), and grand fir (Abies grandis) as derived from the Rules For Grading Logs section of the Official Rules Handbook. Results were compared with certified scalers employed by Yamhill Log Scaling & Grading Bureau and Columbia River Log Scaling & Grading Bureau. Eighty-four individuals measured the length, scaling diameter, determined merchantability versus nonmerchantability and assigned log grade for 440 logs. Results showed participants in the study correctly measuring log length 99% of time, scaling diameters were recorded correctly at an 89% rate, and merchantability and log grade at 98 and 97%, respectively. West. J. Appl. For. 18(4):250–258.


2004 ◽  
Vol 34 (4) ◽  
pp. 800-809 ◽  
Author(s):  
J M Kranabetter ◽  
K D Coates

Silviculture systems (clear-cut, partial-cut, and unharvested forest) were compared 9–10 years after harvesting to determine their effects on conifer nutrition and the availability of soil resources, especially nitrogen. These results were used to discuss the effects of silviculture systems on tree growth in relation to the more commonly described effects of light. Differences in soil properties across the silviculture treatments were most apparent in the forest floor. Depth and C/N ratio of the forest floor had decreased slightly in clearcuts, and forest-floor moisture was highest under partial-cut forest. Despite these differences in soil chemistry and soil moisture, no differences were detected in mineralizable N (anaerobic incubation) or in situ net N mineralization among treatments. Height growth and foliar mass were reduced under the low-light conditions of the partial-cut forest, but there were no differences in foliar N concentrations of hybrid white spruce (Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière), western redcedar (Thuja plicata Dougl. ex D. Don), or western hemlock (Tsuga heterophylla (Raf.) Sarg.) saplings. Mature western hemlock trees in partial-cut forest also had concentrations of foliar N equal to that of mature trees in the unharvested forest. Overall, we detected only minor effects of silviculture systems on soils after 10 years, and we conclude that light availability is likely more responsible for the current differences in tree growth.


2012 ◽  
Vol 78 (3) ◽  
pp. 572-582 ◽  
Author(s):  
Terri Lacourse ◽  
J. Michelle Delepine ◽  
Elizabeth H. Hoffman ◽  
Rolf W. Mathewes

AbstractPollen and conifer stomata analyses of lake sediments from Hippa Island on the north coast of British Columbia were used to reconstruct the vegetation history of this small hypermaritime island. Between 14,000 and 13,230 cal yr BP, the island supported diverse herb–shrub communities dominated by Cyperaceae, Artemisia and Salix. Pinus contorta and Picea sitchensis stomata indicate that these conifers were present among the herb–shrub communities, likely as scattered individuals. Transition to open P. contorta woodland by 13,000 cal yr BP was followed by increases in Alnus viridis, Alnus rubra and P. sitchensis. After 12,000 cal yr BP, Pinus-dominated communities were replaced by dense P. sitchensis and Tsuga heterophylla forest with Lysichiton americanus and fern understory. Thuja plicata stomata indicate that this species was present by 8700 cal yr BP, but the pollen record suggests that its populations did not expand to dominate regional rainforests, along with Tsuga and Picea, until after 6600 cal yr BP. Conifer stomata indicate that species may be locally present for hundreds to thousands of years before pollen exceed thresholds routinely used to infer local species arrival. When combined, pollen and conifer stomata can provide a more accurate record of paleovegetation than either when used alone.


New Forests ◽  
2006 ◽  
Vol 33 (2) ◽  
pp. 139-153 ◽  
Author(s):  
Seamus Kennedy ◽  
Kevin Black ◽  
Conor O’Reilly ◽  
Áine Ní Dhubháin

2010 ◽  
Vol 73 (2) ◽  
pp. 259-268 ◽  
Author(s):  
Thomas A. Ager ◽  
Paul E. Carrara ◽  
Jane L. Smith ◽  
Victoria Anne ◽  
Joni Johnson

An AMS radiocarbon-dated pollen record from a peat deposit on Mitkof Island, southeastern Alaska provides a vegetation history spanning ∼12,900 cal yr BP to the present. Late Wisconsin glaciers covered the entire island; deglaciation occurred > 15,400 cal yr BP. The earliest known vegetation to develop on the island (∼12,900 cal yr BP) was pine woodland (Pinus contorta) with alder (Alnus), sedges (Cyperaceae) and ferns (Polypodiaceae type). By ∼12,240 cal yr BP, Sitka spruce (Picea sitchensis) began to colonize the island while pine woodland declined. By ∼11,200 cal yr BP, mountain hemlock (Tsuga mertensiana) began to spread across the island. Sitka spruce-mountain hemlock forests dominated the lowland landscapes of the island until ∼10,180 cal yr BP, when western hemlock (Tsuga heterophylla) began to colonize, and soon became the dominant tree species. Rising percentages of pine, sedge, and sphagnum after ∼7100 cal yr BP may reflect an expansion of peat bog habitats as regional climate began to shift to cooler, wetter conditions. A decline in alders at that time suggests that coastal forests had spread into the island's uplands, replacing large areas of alder thickets. Cedars (Chamaecyparis nootkatensis, Thuja plicata) appeared on Mitkof Island during the late Holocene.


2001 ◽  
Vol 31 (2) ◽  
pp. 302-312 ◽  
Author(s):  
Thomas J Brandeis ◽  
Michael Newton ◽  
Elizabeth C Cole

In a multilevel study to determine limits to underplanted conifer seedling growth, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex D. Don), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings were planted beneath second-growth Douglas-fir stands that had been thinned to basal areas ranging from 16 to 31 m2/ha. Understory vegetation was treated with a broadcast herbicide application prior to thinning, a directed release herbicide application 2 years later, or no treatment beyond harvest disturbance. Residual overstory density was negatively correlated with percent survival for all four species. Broadcast herbicide application improved survival of grand fir and western hemlock. Western redcedar, grand fir, and western hemlock stem volumes were inversely related to overstory tree density, and this effect increased over time. There was a strong indication that this was also the case for Douglas-fir. Reduction of competing understory vegetation resulted in larger fourth-year stem volumes in grand fir and western hemlock.


2003 ◽  
Vol 33 (2) ◽  
pp. 313-324 ◽  
Author(s):  
J M Kranabetter ◽  
A Banner ◽  
J Shaw

We compared height growth and nutrition (foliar nutrient concentrations and retranslocation rates from 1-year-old needles) of second-growth plantations on imperfectly drained, lower productivity cedar–hemlock–salal forests with those of more productive ecosystems of north coastal British Columbia. Soils ranged from deep organic profiles to well-drained mineral soils derived from igneous to metamorphic bedrock. Leader increments on imperfectly drained sites were smaller than on well-drained sites, averaging 42% less for western hemlock (Tsuga heterophylla (Raf.) Sarg.), 56% less for Sitka spruce (Picea sitchensis (Bong.) Carrière), and 32% less for western redcedar (Thuja plicata Donn ex D. Don). Strong linear correlations were found between leader increment and foliar N, P, and S concentrations for all three tree species, and baseline foliar data for productive sites were presented. The foliar N ratios with P, S, and K were consistent across sites and indicated that many key foliar nutrients increased proportionally to the availability of N. A comparison of nutrient concentrations between current and 1-year-old foliage generally showed little difference on poorer sites, which suggested that there had been no retranslocation of nutrients from young needles within trees to compensate for low soil nutrient availability. This study confirmed the inherently low productivity of cedar-hemlock-salal forests, especially on granodiorite and gneissic diorite bedrock types, and suggested the need for site treatments or long rotations for sustainable management.


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