scholarly journals Microsites and structures used by fishers (Pekania pennanti) in the southern Sierra Nevada: A comparison of forest elements used for daily resting relative to reproduction

2020 ◽  
Author(s):  
RE Green ◽  
KL Purcell ◽  
CM Thompson ◽  
DA Kelt ◽  
Heiko Wittmer

© 2019 Many wildlife species rely on unique features of trees during daily activities and fundamental parts of their life cycle. The fisher (Pekania pennanti) is a forest-dwelling carnivore of conservation concern in western North America that uses unique habitat elements as refuges during resting bouts and for reproduction. Prior to this study, little was known about the fine-scale habitat used during reproduction at the southernmost extent of the fisher's range. Between 2007 and 2015, we attached radio-collars to 55 male and 72 female fishers in the southern Sierra Nevada and documented resting locations of males on 216 occasions (196 structures) and females on 824 occasions (737 structures). Beginning in 2008, we also monitored females over 8 reproductive seasons, confirming 45 females at dens and documenting 95 natal dens (83 structures) and 206 maternal dens (192 structures). We established 3 comparisons to guide our assessment of fine-scale habitat: resting males versus resting females, natal dens versus maternal dens, and resting fishers (both sexes) versus denning fishers (all dens). We expected the need for physical security and thermal protection in combination with morphology, predation risk, and aspects of reproductive ecology would influence patterns of use. Both sexes used a variety of microsites for resting, but females selected tree cavities most frequently (47%) while males used branch platforms most often (39%). For resting structures, live conifers were used most often by both sexes (males 44%, females 34%), but live hardwoods (males 16%, females 28%) and conifer snags (males 16%, females 22%) were also important. Comparing natal and maternal dens, we found that cavity microsites used early in the den season tended to be higher than those used later, and large live hardwoods comprised roughly half of all natal (46%) and maternal (51%) den structures. For resting versus denning, we found that large diameter hardwoods were an important source of cavities for both activities, live conifers used for denning were larger than those used for resting, and den structures tended to be on steeper slopes than rest structures. White fir (Abies concolor), California black oak (Quercus kelloggii), and ponderosa pine (Pinus ponderosa) were selected most often by both sexes for resting. In contrast, denning females relied on California black oak (55%), but also used white fir (24%) and incense cedar (Calocedrus decurrens; 12%). As noted in studies further north, our findings highlight the value of large trees with decay to support fisher reproduction and daily refugia.

2020 ◽  
Author(s):  
RE Green ◽  
KL Purcell ◽  
CM Thompson ◽  
DA Kelt ◽  
Heiko Wittmer

© 2019 Many wildlife species rely on unique features of trees during daily activities and fundamental parts of their life cycle. The fisher (Pekania pennanti) is a forest-dwelling carnivore of conservation concern in western North America that uses unique habitat elements as refuges during resting bouts and for reproduction. Prior to this study, little was known about the fine-scale habitat used during reproduction at the southernmost extent of the fisher's range. Between 2007 and 2015, we attached radio-collars to 55 male and 72 female fishers in the southern Sierra Nevada and documented resting locations of males on 216 occasions (196 structures) and females on 824 occasions (737 structures). Beginning in 2008, we also monitored females over 8 reproductive seasons, confirming 45 females at dens and documenting 95 natal dens (83 structures) and 206 maternal dens (192 structures). We established 3 comparisons to guide our assessment of fine-scale habitat: resting males versus resting females, natal dens versus maternal dens, and resting fishers (both sexes) versus denning fishers (all dens). We expected the need for physical security and thermal protection in combination with morphology, predation risk, and aspects of reproductive ecology would influence patterns of use. Both sexes used a variety of microsites for resting, but females selected tree cavities most frequently (47%) while males used branch platforms most often (39%). For resting structures, live conifers were used most often by both sexes (males 44%, females 34%), but live hardwoods (males 16%, females 28%) and conifer snags (males 16%, females 22%) were also important. Comparing natal and maternal dens, we found that cavity microsites used early in the den season tended to be higher than those used later, and large live hardwoods comprised roughly half of all natal (46%) and maternal (51%) den structures. For resting versus denning, we found that large diameter hardwoods were an important source of cavities for both activities, live conifers used for denning were larger than those used for resting, and den structures tended to be on steeper slopes than rest structures. White fir (Abies concolor), California black oak (Quercus kelloggii), and ponderosa pine (Pinus ponderosa) were selected most often by both sexes for resting. In contrast, denning females relied on California black oak (55%), but also used white fir (24%) and incense cedar (Calocedrus decurrens; 12%). As noted in studies further north, our findings highlight the value of large trees with decay to support fisher reproduction and daily refugia.


2011 ◽  
Vol 41 (10) ◽  
pp. 2051-2063 ◽  
Author(s):  
Seth W. Bigelow ◽  
Malcolm P. North ◽  
Carl F. Salk

Many semi-arid coniferous forests in western North America have reached historically unprecedented densities over the past 150 years and are dominated by shade-tolerant trees. Silvicultural treatments generally open the canopy but may not restore shade-intolerant species. We determined crossover-point irradiance (CPI) (light at which the height growth rank of pairs of species changes) for seedlings in Sierra Nevada mixed-conifer forest and used these to interpret light environments produced by fuels-reduction thinning and group selection with reserved large trees. Nine of 21 species pairs had well-defined CPIs. The CPI of the most common shade-tolerant and intolerant species (white fir ( Abies concolor (Gordon & Glendl.) Lindl. ex Hildebr.) and ponderosa pine ( Pinus ponderosa Douglas ex P. Lawson & C. Lawson)) was 22.5 mol·m–2·day–1 or 41% of full sun. Median understory irradiance increased from 9.2 mol·m–2·day–1 (17% full sun) in pretreatment forest to 13 mol·m–2·day–1 (24% full sun) in lightly and 15.5 mol·m–2·day–1 (28% full sun) in moderately thinned stands and 37 mol·m–2·day–1 (67% full sun) in group-selection openings. We estimate that 5%–20% of ground area in lightly to moderately thinned stands would have enough light to favor shade-intolerant over shade-tolerant growth compared with 89% of ground area in group-selection openings. The CPI provides a tool to assess regeneration implications of treatment modification such as increasing heterogeneity of thinning to enhance regeneration or reserving large trees in group-selection openings to maintain wildlife habitat.


2009 ◽  
Vol 18 (7) ◽  
pp. 857 ◽  
Author(s):  
Chad T. Hanson ◽  
Malcolm P. North

With growing debate over the impacts of post-fire salvage logging in conifer forests of the western USA, managers need accurate assessments of tree survival when significant proportions of the crown have been scorched. The accuracy of fire severity measurements will be affected if trees that initially appear to be fire-killed prove to be viable after longer observation. Our goal was to quantify the extent to which three common Sierra Nevada conifer species may ‘flush’ (produce new foliage in the year following a fire from scorched portions of the crown) and survive after fire, and to identify tree or burn characteristics associated with survival. We found that, among ponderosa pines (Pinus ponderosa Dougl. ex. Laws) and Jeffrey pines (Pinus jeffreyi Grev. & Balf) with 100% initial crown scorch (no green foliage following the fire), the majority of mature trees flushed, and survived. Red fir (Abies magnifica A. Murr.) with high crown scorch (mean = 90%) also flushed, and most large trees survived. Our results indicate that, if flushing is not taken into account, fire severity assessments will tend to overestimate mortality and post-fire salvage could remove many large trees that appear dead but are not.


1990 ◽  
Vol 5 (3) ◽  
pp. 79-82 ◽  
Author(s):  
William W. Oliver

Abstract Growth and stand development of ponderosa pine (Pinus ponderosa) were monitored for 20 years after planting at five different square spacings (6, 9, 12, 15, and 18 ft) in the presence or absence of competing shrubs on the westside Sierra Nevada. Mean tree size was positively correlated and stand values negatively correlated with spacing in the absence of competing shrubs. Trees growing with competing shrubs attained 76% of the diameter, 80% of the height, and 58% of the cubic volume of trees free of shrub competition when all spacings were combined. This study suggests that the major effect of shrub competition in ponderosa pine plantations on good sites is to lengthen the rotation. West. J. Appl. For. 5(3):79-82, July 1990.


1999 ◽  
Vol 14 (3) ◽  
pp. 137-143 ◽  
Author(s):  
Dayna M. Ayers ◽  
Donald J. Bedunah ◽  
Michael G. Harrington

Abstract In many western Montana ponderosa pine (Pinus ponderosa) stands, fire suppression and past selective logging of large trees have resulted in conditions favoring succession to dense stands of shade-tolerant, but insect- and disease-prone Douglas-fir (Pseudotsuga menziesii). Stand thinning and understory prescribed burning have been proposed as surrogates for pre-Euro-American settlement ecological processes and as potential treatments to improve declining forest condition and reduce the probability of severe wildfire. To test the effectiveness of these silvicultural techniques on overstory and understory conditions, research is ongoing in the Lick Creek Demonstration Site in the Bitterroot National Forest, Montana. Our research examined the response (mortality and vigor) of the dominant browse species, antelope bitterbrush (Purshia tridentata) and Scouler's willow (Salix scouleriana), to a ponderosa pine stand restoration project utilizing four treatments: (1) a shelterwood cut that removed 53% of the tree basal area; (2) a shelterwood cut with a low fuel consumption burn; (3) a shelterwood cut with a high fuel consumption burn; and (4) a control. Prior to the application of treatments, 1,856 bitterbrush and 871 willow were located, and their survival and vigor subsequently monitored for 2 yr posttreatment. The cut and burn treatments resulted in the greatest reduction in antelope bitterbrush and Scouler's willow density averaging 66% and 24% of pretreatment density, respectively. The shelterwood cut reduced bitterbrush and Scouler's willow density by 35% and 14%, respectively. On treatments receiving a shelterwood cut (all treatments but the control), but where antelope bitterbrush and Scouler's willow did not have fire damage, mortality was 45% for bitterbrush and 20% for willow, respectively. For bitterbrush and Scouler's willow plants that received fire damage, mortality was 72% for bitterbrush and 19% for willow. Although the burn and shelterwood harvest treatments resulted in reduced density of antelope bitterbrush and Scouler's willow 2 yr posttreatment, these treatments increased vigor of both species and created mineral seedbeds that may be necessary for establishment of seedlings. West. J. Appl. For. 14(3):137-143.


1980 ◽  
Vol 112 (8) ◽  
pp. 797-809 ◽  
Author(s):  
J. S. Elkinton ◽  
D. L. Wood

AbstractMale Ips paraconfusus selected a host, ponderosa pine (Pinus ponderosa), over a non-host, white fir (Abies concolor), only after the beetles had bored through the outer bark and into the phloem. Males, when given a choice between bark discs of these tree species in petri dishes, bored readily through the outer bark of either species. However, the beetles penetrated no more than 1 mm into the phloem of white fir, but they bored extensively in the phloem of ponderosa pine. The beetle’s preference for the pine over fir phloem was apparent with intact samples of phloem with the outer bark removed and with ground phloem. No preferences were apparent for the ground or intact pine or fir outer bark, with the phloem removed. The beetles bored preferentially in fissured as opposed to smooth outer bark of either tree. Beetles did not feed in the outer bark but did feed in the phloem of either species. In field experiments beetles attracted to logs of pine and fir bored through the outer bark of each species in nearly equal numbers. In white fir they re-emerged and departed soon after penetration of the phloem, whereas in ponderosa pine they continued excavation of tunnels in the phloem. In contrast, few beetles penetrated even the outer back of incense cedar (Calocedrus decurrens), another non-host species.


Soil Systems ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 41 ◽  
Author(s):  
Craig Rasmussen ◽  
Heather Throckmorton ◽  
Garrett Liles ◽  
Katherine Heckman ◽  
Stephen Meding ◽  
...  

There is a critical need to quantify the role of soil mineral composition on organic carbon (C) stabilization in forest soils. Here, we address this need by studying a matrix of forest ecosystems and soil parent materials with the objective of quantifying controls on the physical partitioning and residence time of soil organic carbon. We sampled soil profiles across a climate gradient on the western slope of the California Sierra Nevada, focusing on three distinct forest ecosystems dominated by ponderosa pine, white fir, or red fir, on three igneous parent materials that included granite, andesite, and basalt. Results indicated that short-range order mineral phases were the dominant factors accounting for the variation in soil carbon content and residence time. The results further suggested an interaction between ecosystem fire regime and the degree of soil weathering on the partitioning, chemical composition, and residence time of C in density separated soil physical fractions. These results suggest a link between the degree of soil weathering and C storage capacity, with a greater divergence in storage capacity and residence time in the Inceptisols, Entisols, and Andisols of the white fir and red fir ecosystems relative to minimal variation in the highly weathered Ultisols and Alfisols of the ponderosa pine ecosystem.


2004 ◽  
Vol 34 (6) ◽  
pp. 1210-1219 ◽  
Author(s):  
Daniel W Omdal ◽  
Charles G Shaw, III ◽  
William R Jacobi

Crown symptoms and other aboveground variables were examined on 36 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco.) (40–209 years old), 46 white fir (Abies concolor (Gord. & Glend.) Lindl.) (36–165 years old), and 97 ponderosa pine (Pinus ponderosa Dougl. ex Laws.) (64–220 years old) trees in northern New Mexico and southern Colorado. Root systems of all trees were excavated to determine extent of root disease. Symptoms observed on infected trees, including reductions in height growth, changes in foliage characteristics, and crown dieback, worsened as the number of infected roots increased. Trees with aboveground symptoms had a significantly higher (p < 0.05) number of infected lateral roots than trees without symptoms. In mixed conifer stands on the Archuleta Mesa, Colo., four qualitative crown symptoms were used to accurately detect Armillaria ostoyae (Romagn.) Herink and (or) Heterobasidion annosum (Fr.) Bref. infection of Douglas-fir (21/22, or 95%) and white fir (19/28, or 68%). Similarly, 61% (48/79) of the A. ostoyae infected ponderosa pine trees on the Jemez site, N.M., were detected using the qualitative Thomson vigor rating system. Discriminate analysis, using more thorough variables and analysis, resulted in correct infection classifications of 82%, 85%, and 78% for Douglas-fir, white fir, and ponderosa pine, respectively, suggesting that aboveground variables are reasonable indicators of root disease.


2021 ◽  
Author(s):  
Mengjun Shu ◽  
Emily V. Moran

Abstract Background Genotype-to-environment (G2E) association analysis coupled with genotype-to-phenotype (G2P) association analysis promises exciting advances towards discovering genes responsible for local adaptation. We combine G2E and G2P analysis with gene annotation in Pinus ponderosa (ponderosa pine), an ecologically and economically important conifer that lacks a sequenced genome, to identify genetic variants and gene functions that may be associated with local adaptation to drought. Results We identified SNP markers in 223 genotypes from across the Sierra Nevada by aligning GBS sequence fragments to the reference genome of Pinus taeda (loblolly pine). Focusing on SNPs in or near coding regions, we found 1458 associated with 5 largely-uncorrelated climate variables, with the largest number (1151) associated with April 1st snow pack. We also planted seeds from a subset of these trees in the greenhouse, subjected half of the seedlings to a drought treatment, and measured phenotypes thought to be associated with drought tolerance, including root length and stomatal density. 817 SNPs were associated with the control-condition values of six traits, while 1154 were associated with responsiveness of these traits to drought. Conclusions While no individual SNPs were associated with both the environmental variables and the measured traits, several categories of genes were associated with both, particularly those involved in cell wall formation, biotic and abiotic stress responses, and ubiquitination. However, functions of many of the associated genes have not yet been determined due to the lack of gene annotation information for trees and future studies are needed.


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