Foraging patterns of pileated woodpeckers in a managed Acadian forest: a resource selection function

2005 ◽  
Vol 35 (10) ◽  
pp. 2387-2393 ◽  
Author(s):  
Jérôme Lemaître ◽  
Marc-André Villard

We analyzed the relative influence of foraging substrate characteristics as predictors of the probability of use by the pileated woodpecker (Dryocopus pileatus L.) and determined threshold values for significant predictors. We sampled used and available substrates around 126 stations distributed in an intensively managed forest in northwestern New Brunswick, Canada. We developed a resource selection function (RSF), validated by a resampling procedure, and compared selection ratios for significant predictors. Diameter at breast height (DBH) of trees and snags was the most significant predictor, probably reflecting nesting selection by its main prey, carpenter ants (Camponotus spp.). The pileated woodpecker preferred deciduous substrates with DBH >35 cm and coniferous substrates with DBH >30 cm. Among deciduous substrates, it preferred snags over living trees, but there was no such preference for coniferous substrates. American beech (Fagus grandifolia Ehrh.) was clearly preferred over all other species. The RSF we developed and the thresholds we obtained should help forest managers and conservation planners assess habitat quality for this keystone species.

2002 ◽  
Vol 6 (4) ◽  
pp. 213-228 ◽  
Author(s):  
Bryan F. J. Manly

A resource selection probability function is a function that gives the prob- ability that a resource unit (e.g., a plot of land) that is described by a set of habitat variables X1 to Xp will be used by an animal or group of animals in a certain period of time. The estimation of a resource selection function is usually based on the comparison of a sample of resource units used by an animal with a sample of the resource units that were available for use, with both samples being assumed to be effectively randomly selected from the relevant populations. In this paper the possibility of using a modified sampling scheme is examined, with the used units obtained by line transect sampling. A logistic regression type of model is proposed, with estimation by conditional maximum likelihood. A simulation study indicates that the proposed method should be useful in practice.


2013 ◽  
Vol 82 (5) ◽  
pp. 1062-1071 ◽  
Author(s):  
Nicolas Courbin ◽  
Daniel Fortin ◽  
Christian Dussault ◽  
Viviane Fargeot ◽  
Réhaume Courtois

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Carl L. Rosier ◽  
Shawn W. Polson ◽  
Vincent D’Amico ◽  
Jinjun Kan ◽  
Tara L. E. Trammell

AbstractThe soil microbial community (SMC) provides critical ecosystem services including organic matter decomposition, soil structural formation, and nutrient cycling. Studies suggest plants, specifically trees, act as soil keystone species controlling SMC structure via multiple mechanisms (e.g., litter chemistry, root exudates, and canopy alteration of precipitation). Tree influence on SMC is shaped by local/regional climate effects on forested environments and the connection of forests to surrounding landscapes (e.g., urbanization). Urban soils offer an ideal analog to assess the influence of environmental conditions versus plant species-specific controls on SMC. We used next generation high throughput sequencing to characterize the SMC of specific tree species (Fagus grandifolia [beech] vs Liriodendron tulipifera [yellow poplar]) across an urban–rural gradient. Results indicate SMC dissimilarity within rural forests suggests the SMC is unique to individual tree species. However, greater urbanization pressure increased SMC similarity between tree species. Relative abundance, species richness, and evenness suggest that increases in similarity within urban forests is not the result of biodiversity loss, but rather due to greater overlap of shared taxa. Evaluation of soil chemistry across the rural–urban gradient indicate pH, Ca+, and organic matter are largely responsible for driving relative abundance of specific SMC members.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 988
Author(s):  
Anouschka R. Hof ◽  
Anna Zachrisson ◽  
Lina E. Polvi

The speed with which restoration will, or can, be accomplished depends on the initial state and location of the sites. However, many factors can undermine the process of choosing sites that are deemed the best ecological choice for restoration. Little attention has been paid to whether site selection follows ecological criteria and how this may affect restoration success. We used habitat inventory data to investigate whether ecological criteria for site selection and restoration have been followed, focusing on restoration for the white-backed woodpecker (Dendrocopos leucotos B.) in Sweden. In our study region, which is situated in an intensively managed forest landscape with dense and young stands dominated by two coniferous species, purely ecological criteria would entail that sites that are targeted for restoration would (1) initially be composed of older and more deciduous trees than the surrounding landscape, and (2) be at a scale relevant for the species. Furthermore, restoration should lead to sites becoming less dense and less dominated by coniferous trees after restoration, which we investigated as an assessment of restoration progress. To contextualize the results, we interviewed people involved in the restoration efforts on site. We show that although the first criterion for ecological site selection was largely met, the second was not. More research is needed to assess the motivations of actors taking part in restoration efforts, as well as how they interlink with public efforts. This would allow us to identify possible synergies that can benefit restoration efforts.


Author(s):  
Peter N Dudley ◽  
Sara N John ◽  
Miles E Daniels ◽  
Eric M. Danner

In North America, impassable, man-made barriers block access to salmonid spawning habitat and require costly restoration efforts in the remaining habitats. Evaluating restored spawning habitat quality requires information on salmon water velocity and depth preferences, which may vary in relation to other variables (e.g. water temperature). We demonstrate a generalizable, low cost method to gather and analyze this data by combining aerial redd surveys of winter-run Chinook salmon (Oncorhynchus tshawytscha), 2D hydraulic modeling, and generalized linear models to calculate spawning resource selection functions (RSFs). Our method permits the examination of interactions between environmental variables on habitat selection, which are frequently treated as independent. Our methods resulted in a RSF that shows interactions between both velocity and depth preference with changing temperature. Preferred depth increased and preferred velocity decreased with increasing temperature. Spawning RSFs for environmental variables may change as other environmental conditions (i.e. water temperature) change, thus it is importance to account for potential interactions when using or producing RSFs.


2011 ◽  
Vol 41 (6) ◽  
pp. 1295-1307 ◽  
Author(s):  
Robert P. Long ◽  
Stephen B. Horsley ◽  
Thomas J. Hall

Sugar maple (Acer saccharum Marsh.) is a keystone species in the northern hardwood forest, and decline episodes have negatively affected the growth and health of sugar maple in portions of its range over the past 50+ years. Crown health, growth, survival, and flower and seed production of sugar maple were negatively affected by a widespread decline event in the mid-1980s on the unglaciated Allegheny Plateau in northern Pennsylvania. A long-term liming study was initiated in 1985 to evaluate responses to a one-time application of 22.4 Mg·ha–1 of dolomitic limestone in four northern hardwood stands. Over the 23-year period ending in 2008, sugar maple basal area increment (BAINC) increased significantly (P ≤ 0.05) in limed plots from 1995 through 2008, whereas American beech (Fagus grandifolia Ehrh.) BAINC was unaffected. For black cherry (Prunus serotina Ehrh.), the third principal overstory species, BAINC and survival were reduced in limed plots compared with unlimed plots. Foliar Ca and Mg remained significantly higher in sugar maple foliage sampled 21 years after lime application, showing persistence of the lime effect. These results show long-term species-specific responses to lime application.


1988 ◽  
Vol 12 (2) ◽  
pp. 84-89 ◽  
Author(s):  
Alan A. Lucier

Abstract Forest inventory data collected by the USDA Forest Service shows that pine forests in the Southeast have changed in many ways since the 1950s. The average age and density of natural stands has increased substantially over the past 30 years, perhaps reflecting the maturation of a large number of stands established between 1945 and 1965. Growth rates of some classes of trees and stands have decreased, but it is not known whether increases in age and density are largely responsible. The existence of growth reductions in natural stands is an expected consequence of the documented changes in stand conditions. The magnitude of the growth reductions, however, cannot be objectively defined as normal or abnormal on the basis of existing data. Researchers are attempting to define the contributions of stand conditions, drought, land-use patterns, atmospheric pollutants, and other factors to observed growth reductions. There is at present no demonstrated link between air pollutants and growth reductions in natural pine stands and no evidence of growth reductions on intensively managed forest industry lands. South. J. Appl. For. 12(2):84-89.


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