Estimating the biomass of woodland caribou forage lichens

2011 ◽  
Vol 41 (10) ◽  
pp. 1961-1969 ◽  
Author(s):  
Richard Troy McMullin ◽  
Ian D. Thompson ◽  
Brian W. Lacey ◽  
Steven G. Newmaster

Lichens are an important winter food source for woodland caribou ( Rangifer tarandus caribou ), but quantifying their abundance is difficult. Here, we present an efficient method for assessing lichen biomass at the stand level in boreal forests. We measured lichens occurring in high enough abundance to serve as a winter food source for woodland caribou in 51 boreal forest stands. Samples of each species or genus were collected from each stand and a mean abundance (cover) to biomass ratio was established. The method does not require samples to be collected or weighed, due to this predetermined relationship, and it also accounts for the variation in biomass among lichen species that are equally abundant. The variation in lichen growth between stands was assessed by means of five lichen abundance classes. The proposed method was tested in 34 stands with a wide range of ages and stem densities. The average time to complete a lichen biomass assessment was approximately 2 h. This method is an efficient and accurate tool that can assist forest managers and researchers with ecological studies on lichens or with monitoring changes in lichen biomass over time and with habitat assessments for organisms for which lichens are important, such as woodland caribou.

Rangifer ◽  
1991 ◽  
Vol 11 (4) ◽  
pp. 91 ◽  
Author(s):  
E. Janet Edmonds

A review of current population size and trends of woodland caribou (Rangifer tarandus caribou) in seven jurisdictions in western North America shows a wide range of situations. A total maximum population estimate of woodland caribou west of the Ontario/Manitoba border is 61 090. Of 44 herds or populations described in this review: 14 are stable; two are stable to slightly decreasing; four are decreasing; four are increasing; and 22 are of unknown status. Caribou are classified as a threatened species in Alberta and as an endangered species in Washington/Idaho. The decline of caribou in North America following settlement (Bergerud, 1974) has continued along the southern edge of woodland caribou distribution. Direct loss of habitat to logging, mines and dams continued throughout the I960s, 1970s and 1980s. The secondary effects of these habitat changes, (i.e. increased roads leading to increased hunting and poaching, and increased early succession habitat leading to increased alternate prey/predator densities) has led in some cases to the total loss or decreased size of local herds. Three ecotypes of woodland caribou are described and their relative distribution delineated. These ecotypes live under different environmental conditions and require different inventory and management approaches. Woodland caribou herds in northern B.C., Yukon and N.W.T. generally are of good numbers and viable (stable or increasing), and management primarily is directed at regulating human harvest and natural predation to prevent, herd declines. Land use activities such as logging or energy development are not extensive. Managers in southern caribou ranges stress the need for a better understanding of caribou population stability within mixed prey/predator regimes; how habitat changes (eg. through logging) affect these regimes; and how to develop effective land use guidelines for resource extraction that can sustian caribou populations and maintain resource industries. Caribou managers have suggested that herds may be priorized for research and management efforts. Unstable, remnant populations may be left to their own fate. The limited research dollars available and difficult management decisions should be applied to caribou herds that are apparently sustainable and provide the greatest potential for long-term viability.


2015 ◽  
Vol 93 (2) ◽  
pp. 87-98 ◽  
Author(s):  
Ian D. Thompson ◽  
Philip A. Wiebe ◽  
Erin Mallon ◽  
Arthur R. Rodgers ◽  
John M. Fryxell ◽  
...  

We used remote video cameras to assess seasonal diet composition of woodland caribou (Rangifer tarandus tarandus (L., 1758)) at three areas across the boreal forest of Ontario. Caribou consume lichens in winter, but we expected they would significantly reduce lichen consumption in favour of higher protein levels in green plants in summer. We sampled videos from 23 caribou, from 2 years, to derive seasonal diet composition. Diet differed among seasons and study areas, except in winter when lichens dominated. Diet breadth doubled from winter to summer, but overlap between seasons was still >60%. Green plants were less commonly eaten than we expected, only three genera were preferred, and few species constituted more than 2% of the diet. Preferred foods varied by land-cover types. Diet differed between managed and unmanaged landscapes but did not result from use of plant species found in successional habitats. Caribou selected a nonoptimal diet in the snow-free seasons, especially with respect to protein, suggesting factors other than nutrition influenced diet choice, and indicating the possibility of bottom-up limitation on production.


Rangifer ◽  
1998 ◽  
Vol 18 (5) ◽  
pp. 111 ◽  
Author(s):  
J. Edmonds

A recent review of woodland caribou {Rangifer tarandus caribou) status in Alberta estimated that there are between 3600 and 6700 caribou occupying 113 000 km2 of habitat. There are two ecotypes of caribou in Alberta; the mountain ecotype in the west central region and the boreal ecotype primarily in the north. Mountain caribou populations are stable or declining and boreal populations, where data are available, appear to be stable or declining slowly. A major initiative in caribou management in Alberta has been the development of the Woodland Caribou Conservation Strategy. This document was developed over two and a half years by a committee of multi-stakeholder representatives. The past five years has seen an increase in baseline inventory and applied research jointly funded by government, industry and universities, addressing a wide range of management issues from caribou response to logging to interactions of moose, wolves and caribou in the boreal ecosystem. Land use conflicts on caribou range remain high with timber harvesting, oil and gas development, peat moss extraction, coal mining, agricultural expansion and increasing road access overlapping. Cumulative effects of these disturbances are poorly understood and have received little attention to date.


2016 ◽  
Vol 46 (7) ◽  
pp. 914-923 ◽  
Author(s):  
Jonathan L.W. Ruppert ◽  
Marie-Josée Fortin ◽  
Eldon A. Gunn ◽  
David L. Martell

The fragmentation and loss of old-growth forest has led to the decline of many forest-dwelling species that depend on old-growth forest as habitat. Emblematic of this issue in many areas of the managed boreal forest in Canada is the threatened woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). We develop a methodology to help determine when and how timber can be harvested to best satisfy both industrial timber supply and woodland caribou habitat requirements. To start, we use least-cost paths based on graph theory to determine the configuration of woodland caribou preferred habitat patches. We then developed a heuristic procedure to schedule timber harvesting based on a trade-off between merchantable wood volume and the remaining amount of habitat and its connectivity during a planning cycle. Our heuristic can attain 84% of the potential woodland caribou habitat that would be available in the absence of harvesting at the end of a 100 year planning horizon. Interestingly, this is more than that which is attained by the current plan (50%) and a harvesting plan that targets high volume stands (32%). Our results indicate that our heuristic procedure (i.e., an ecologically tuned optimization approach) may better direct industrial activities to improve old-growth habitat while maintaining specified timber production levels.


Author(s):  
Brian Coupal ◽  
Paula Bentham

The federal Recovery Strategy for the Woodland Caribou (Rangifer tarandus caribou), Boreal Population in Canada, identifies coordinated actions to reclaim woodland caribou habitat as a key step to meeting current and future caribou population objectives. Actions include restoring industrial landscape features such as roads, seismic lines, pipelines, cut-lines, and cleared areas in an effort to reduce landscape fragmentation and the changes in caribou population dynamics associated with changing predator-prey dynamics in highly fragmented landscapes. Reliance on habitat restoration as a recovery action within the federal Recovery Strategy is high, identifying 65% undisturbed habitat in a caribou range as the threshold to providing a 60% chance that a local population will be self-sustaining. In alignment with the federal Recovery Strategy, Alberta’s Provincial Woodland Caribou Policy identifies habitat restoration as a critical component of long-term caribou habitat management. Habitat restoration initiatives of Alberta’s historical industrial footprint within caribou ranges began in 2001 and have largely focused on linear corridors, including pipelines. Initiatives include revegetation treatments, access control programs and studies, and restricting the growth of plant species that are favourable to moose and deer, the primary prey for wolves. Habitat restoration for pipelines also includes pre-construction planning to reduce disturbance and create line-of-sight breaks, and construction techniques that promote natural vegetation recovery. Lessons learned from habitat restoration programs implemented on pipeline projects in northeastern Alberta will be shared as an opportunity to improve common understanding of restoration techniques, the barriers to implementation, and potential outcomes.


2021 ◽  
Vol 17 (2) ◽  
pp. e1008635
Author(s):  
Gerrit Ansmann ◽  
Tobias Bollenbach

Many ecological studies employ general models that can feature an arbitrary number of populations. A critical requirement imposed on such models is clone consistency: If the individuals from two populations are indistinguishable, joining these populations into one shall not affect the outcome of the model. Otherwise a model produces different outcomes for the same scenario. Using functional analysis, we comprehensively characterize all clone-consistent models: We prove that they are necessarily composed from basic building blocks, namely linear combinations of parameters and abundances. These strong constraints enable a straightforward validation of model consistency. Although clone consistency can always be achieved with sufficient assumptions, we argue that it is important to explicitly name and consider the assumptions made: They may not be justified or limit the applicability of models and the generality of the results obtained with them. Moreover, our insights facilitate building new clone-consistent models, which we illustrate for a data-driven model of microbial communities. Finally, our insights point to new relevant forms of general models for theoretical ecology. Our framework thus provides a systematic way of comprehending ecological models, which can guide a wide range of studies.


Rangifer ◽  
2005 ◽  
Vol 25 (4) ◽  
pp. 89
Author(s):  
Paula R. Bentham

Since 1985, woodland caribou (Rangifer tarandus caribou) have been designated as a threatened species in Alberta. Populations studied since the 1970s have been stable or declining, with no population increases documented. Resource expansion into previously undeveloped areas and associated increases in access have been implicated as possible causes for the declines. To facilitate development on caribou ranges, while ensuring the integrity and supply of caribou habitat, standing committees have been formed. The primary role of the committees is to act as advisory bodies to the government and to search for effective and efficient industrial operating guidelines. Recent research has been conducted on the responses of woodland caribou ecotypes to increased human and predator access. Based on this research, operating guidelines have been refined and implemented through Caribou Protection Plans. I discuss how the current operating guidelines are put into practice and linked to the Environmental Assessment process within the Oil Sands Region of Alberta. In particular, I discuss the origination of impact predictions, specific mitigation measures to reduce impacts and monitoring.


1977 ◽  
Vol 41 (3) ◽  
pp. 590 ◽  
Author(s):  
David J. Rofritz
Keyword(s):  

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