Interrelationships among northern flying squirrels, truffles, and microhabitat structure in Sierra Nevada old-growth habitat

2002 ◽  
Vol 32 (6) ◽  
pp. 1016-1024 ◽  
Author(s):  
Sanjay Pyare ◽  
William S Longland
Keyword(s):  
Sierra Nevada ◽  
Forest Floor ◽  
Woody Debris ◽  
Fungal Growth ◽  
Old Growth ◽  
Flying Squirrels ◽  
Old Growth Forest ◽  
Northern Flying Squirrels ◽  
Nesting Sites ◽  
Microhabitat Structure

During 1997-1998, we investigated the influence of both the relative abundance of truffles, preferred food items, and microhabitat structure on the occurrence of northern flying squirrels (Glaucomys sabrinus Shaw) in old-growth forest habitat of the Sierra Nevada Range, U.S.A. Following live-trapping sessions, we searched the forest floor for truffle diggings and sampled the soil for truffles. Diggings were more abundant where flying squirrels were captured, suggesting squirrels were active near areas of the forest floor where truffles had recently been excavated. The frequency of sampling plots with truffles was higher where squirrels were captured, further suggesting preferences for microhabitats where truffles were more abundant. We also measured 15 microhabitat variables at trap stations to evaluate the influence of aboveground microhabitat characteristics on squirrel occurrence. Results indicated that flying squirrels preferred microhabitats with understory cover, which may minimize predation from aerial predators like spotted owls (Strix occidentalis Merriam). Neither abundance of coarse woody debris, a feature conducive to fungal growth, nor the abundance of potential nesting sites (i.e., snags) measurably influenced squirrel occurrence. While various aboveground forest-microhabitat characteristics affect the use of old-growth forests by flying squirrels, these animals refine their use of these forests based on fine-scale changes in the availability of a highly preferred and ephemeral food item.

Mechanisms of truffle detection by northern flying squirrels

2001 ◽  
Vol 79 (6) ◽  
pp. 1007-1015 ◽  
Author(s):  
Sanjay Pyare ◽  
William S Longland
Keyword(s):  
Sierra Nevada ◽  
Coarse Woody Debris ◽  
Forest Floor ◽  
Detection Rate ◽  
Food Source ◽  
Potential Role ◽  
Woody Debris ◽  
Glaucomys Sabrinus ◽  
Flying Squirrels ◽  
Northern Flying Squirrels

The objective of this study was to evaluate how northern flying squirrels (Glaucomys sabrinus) locate truffles (Gautieria monticola), a subterranean and ephemeral but primary food source. Thus, we evaluated the importance of three factors to the foraging behavior of northern flying squirrels: (i) olfactory chemicals that emanate from truffles; (ii) the presence of coarse woody debris (decaying logs), which are often associated with fungi; and (iii) we explored the potential role animal memory could play in truffle detection as well. In a foraging arena, squirrels successfully retrieved buried truffles that lacked aboveground cues in 19 of 30 trials and failed to search near treatments that lacked truffles altogether, confirming the importance of olfaction to squirrel foraging. However, squirrels also retrieved truffles that were associated most frequently with surface logs (27 of 30). In addition, the initial detection rate of the truffle + log treatment was significantly greater than the truffle-only treatment. Thus, although squirrels search for truffles primarily using olfaction, they may also benefit by searching near coarse woody debris on the forest floor as an aboveground cue to truffle locations. In addition, because 82% of Sierra Nevada truffle-fruiting locations that were marked in 1996 yielded truffles again the following 2 years, mycophagous animals like northern flying squirrels may benefit by memorizing fruiting locations and foraging at these same locations from year to year.

Seasonal and yearly changes in consumption of hypogeous fungi by northern flying squirrels and red squirrels in old-growth forest, New Brunswick

2004 ◽  
Vol 82 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Karl Vernes ◽  
Shauna Blois ◽  
Felix Bärlocher
Keyword(s):  
New Brunswick ◽  
Mycorrhizal Fungus ◽  
Food Resource ◽  
Faecal Pellet ◽  
Old Growth ◽  
Red Squirrels ◽  
Hypogeous Fungi ◽  
Flying Squirrels ◽  
Old Growth Forest ◽  
Northern Flying Squirrels

Seasonal consumption of mycorrhizal fungus by northern flying squirrels (Glaucomys sabrinus) and red squirrels (Tamiasciurus hudsonicus) was examined in old-growth mixedwood forest at Fundy National Park in southern New Brunswick between May 1999 and March 2001. Using faecal pellet analysis, we found that the amount of fungus in the diet of both species was dependent on season and year of study and ranged from 35% to 95%. Twenty fungal taxa, most of them hypogeous Ascomycetes and Basidiomycetes, were detected in diets. More taxa were detected in summer diets compared with all other seasons, but all seasonal samples contained several hypogeous taxa. Up to six taxa were identified in any one sample. Both squirrel species occurred at high densities throughout the study, and dietary overlap between them was great throughout this time in terms of both the amount of fungus and the proportions of different taxa that were consumed. Overall, our data suggest that both G. sabrinus and T. hudsonicus are abundant and important consumers of fungus in the region and that fungus may represent a key food resource, particularly during times when other foods are limited.

Comparison of coniferous forest carbon stocks between old-growth and young second-growth forests on two soil types in central British Columbia, Canada

2005 ◽  
Vol 35 (6) ◽  
pp. 1411-1421 ◽  
Author(s):  
Arthur L Fredeen ◽  
Claudette H Bois ◽  
Darren T Janzen ◽  
Paul T Sanborn
Keyword(s):  
British Columbia ◽  
Forest Floor ◽  
Woody Debris ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Old Growth ◽  
Soil C ◽  
Old Growth Forest ◽  
Second Growth ◽  
C Stocks

Carbon (C) stocks were assessed for hybrid interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.)-dominated upland forests within the Aleza Lake Research Forest in central British Columbia, Canada. Four old-growth (141–250 years old) and four young second-growth (<20 years old) forest plots were established on the two dominant soil texture types, coarse and fine, for a total of 16 plots. Mean total C stocks for old-growth stands ranged from 423 Mg C·ha–1 (coarse) to 324 Mg C·ha–1 (fine), intermediate between Pacific Northwest temperate forests and upland boreal forests. Total C was lower in second-growth stands because of lower tree (mostly large tree stem), forest floor, and woody debris C stocks. In contrast, old-growth forest-floor C stocks ranged from 78 Mg C·ha–1 (coarse) to 35 Mg C·ha–1 (fine), 2.9- and 1.2-fold higher than in corresponding second-growth stands, respectively. Woody debris C stocks in old-growth stands totaled 35 Mg C·ha–1 (coarse) and 31 Mg C·ha–1 (fine), 2.7- and 3.4-fold higher than in second-growth stands, respectively. Mineral soil C to 1.07 m depth was similar across soil type and age-class, with totals ranging from 115 to 106 Mg C·ha–1. Harvesting of old-growth forests in sub-boreal British Columbia lowers total C stocks by 54%–41%.

scholarly journals Bryophyte Conservation in Managed Boreal Landscapes: Fourteen-Year Impacts of Partial Cuts on Epixylic Bryophytes

2021 ◽  
Vol 4 ◽  
Author(s):  
Jeffrey Opoku-Nyame ◽  
Alain Leduc ◽  
Nicole J. Fenton
Keyword(s):  
Species Composition ◽  
Coarse Woody Debris ◽  
Black Spruce ◽  
Woody Debris ◽  
Permanent Plots ◽  
Old Growth ◽  
Clear Cut ◽  
Old Growth Forest ◽  
Old Growth Forests ◽  
Over Time

Clear cut harvest simplifies and eliminates old growth forest structure, negatively impacting biodiversity. Partial cut harvest has been hypothesized (1) to have less impact on biodiversity than clear cut harvest, and (2) to encourage old growth forest structures. Long-term studies are required to test this hypothesis as most studies are conducted soon after harvest. Using epixylic bryophytes as indicators, this study addresses this knowledge gap. Fourteen years after harvest, we examined changes in epixylic bryophyte community composition richness and traits, and their microhabitats (coarse woody debris characteristics and microclimate) along an unharvested, partial cuts and clear cuts harvest treatment in 30 permanent plots established in the boreal black spruce (Picea mariana) forests of northwestern Quebec, Canada. Our results were compared to those of an initial post-harvest study (year 5) and to a chronosequence of old growth forests to examine species changes over time and the similarity of bryophyte communities in partial cut and old growth forests. Coarse woody debris (CWD) volume by decay class varied among harvest treatments with partial cuts and clear cuts recording lower volumes of early decay CWD. The epixylic community was richer in partial cuts than in mature unharvested forests and clear cuts. In addition, species richness and overall abundance doubled in partial and clear cuts between years 5 and 14. Species composition also differed among treatments between years 5 and 14. Furthermore, conditions in partial cut stands supported small, drought sensitive, and old growth confined species that are threatened by conditions in clear cut stands. Lastly, over time, species composition in partial cuts became more similar to old growth forests. Partial cuts reduced harvest impacts by continuing to provide favorable microhabitat conditions that support epixylic bryophytes. Also, partial cut harvest has the potential to encourage old growth species assemblages, which has been a major concern for biodiversity conservation in managed forest landscapes. Our findings support the promotion of partial cut harvest as an effective strategy to achieve species and habitat conservation goals.

Dynamics of coarse woody debris and decomposition rates in an old-growth forest in lower tropical China

2010 ◽  
Vol 259 (8) ◽  
pp. 1666-1672 ◽  
Author(s):  
Fang-Fang Yang ◽  
Yue-Lin Li ◽  
Guo-Yi Zhou ◽  
K.O. Wenigmann ◽  
De-Qiang Zhang ◽  
...  
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Decomposition Rates ◽  
Old Growth ◽  
Old Growth Forest ◽  
Tropical China

scholarly journals Fungi in the diets of northern flying squirrels and lodgepole chipmunks in the Sierra Nevada

2005 ◽  
Vol 83 (12) ◽  
pp. 1581-1589 ◽  
Author(s):  
Marc D Meyer ◽  
Malcolm P North ◽  
Douglas A Kelt
Keyword(s):  
Sierra Nevada ◽  
Glaucomys Sabrinus ◽  
Dietary Overlap ◽  
Conifer Forest ◽  
Seasonal Differences ◽  
Flying Squirrels ◽  
Northern Flying Squirrel ◽  
Mixed Conifer Forest ◽  
Northern Flying Squirrels ◽  
Teakettle Experimental Forest

The diets of a fungal specialist, northern flying squirrel (Glaucomys sabrinus (Shaw, 1801)), and a dietary generalist, lodgepole chipmunk (Neotamias speciosus (Merriam, 1890)), were examined in the old-growth, mixed-conifer forest at the Teakettle Experimental Forest in California's southern Sierra Nevada. Spores of fungi were identified from fecal pellets collected from both species during spring and summer of 1999 through 2002. Frequency of fungi in the diets of both squirrel species was consistently high across all seasons and years of study. Overall, G. sabrinus diets contained about 30% greater richness and evenness of fungal taxa than N. speciosus diets. There were no seasonal differences in richness and evenness of fungal taxa in squirrel diets. Richness of fungal taxa in diets was positively correlated with hypogeous sporocarp biomass and rainfall from June through August for N. speciosus but not for G. sabrinus. Dietary overlap between G. sabrinus and N. speciosus was high with respect to the most frequently consumed fungal taxa, although Gautieria and Gastroboletus were consumed in greater proportions by G. sabrinus than N. speciosus. Our results indicate that in the southern Sierra Nevada both G. sabrinus and N. speciosus were frequent consumers of a similar, diverse assemblage of fungal taxa and that consumption was proportional to seasonal differences in availability. For the more strongly mycophagist G. sabrinus, however, diet had a greater proportion of select fungal taxa and avoidance of less desirable taxa.

Population dynamics of Glaucomys sabrinus and Tamiasciurus douglasii in old-growth and second-growth stands of coastal coniferous forest

2003 ◽  
Vol 33 (4) ◽  
pp. 587-596 ◽  
Author(s):  
Douglas B Ransome ◽  
Thomas P Sullivan
Keyword(s):  
Population Dynamics ◽  
Habitat Preferences ◽  
Coniferous Forest ◽  
Glaucomys Sabrinus ◽  
Old Growth ◽  
Flying Squirrels ◽  
Survival Percentage ◽  
Second Growth ◽  
Northern Flying Squirrels ◽  
Population Breeding

Habitat preferences and population dynamics of northern flying squirrels (Glaucomys sabrinus Shaw) and Douglas squirrels (Tamiasciurus douglasii Audubon and Bachman) were examined in old-growth and mature second-growth stands in British Columbia, Canada. Using mark–recapture techniques to estimate population dynamics, we tested the hypothesis that old-growth stands provided higher-quality habitat than second-growth stands for these species. Populations were monitored in two old-growth and two mature second-growth stands from August 1995 to May 1999. We were unable to detect major differences in movement, density, recruitment, mass of males, survival, percentage of the population breeding, and the duration that individuals remained on the study plots between stand types for G. sabrinus. Similarly, with the exception of recruitment, we were unable to detect major differences in these parameters between stand types for T. douglasii. Recruitment of T. douglasii was higher in second-growth than in old-growth stands. Old-growth stands were not higher-quality habitat than second-growth stands for either species for the period of enquiry and the parameters we measured. We also presented evidence of late fall – early winter breeding for G. sabrinus, as well as seasonal fluctuations in mass and trappability, larger movement by males than females, and the age of some squirrels exceeding 3.5 years.

Decomposition and nutrient dynamics of ponderosa pine needles in a Mediterranean-type climate

1992 ◽  
Vol 22 (3) ◽  
pp. 306-314 ◽  
Author(s):  
Stephen C. Hart ◽  
Mary K. Firestone ◽  
Eldor A. Paul
Keyword(s):  
Sierra Nevada ◽  
Ponderosa Pine ◽  
Nutrient Dynamics ◽  
Decay Rates ◽  
Litter Fall ◽  
Decomposition Rates ◽  
Old Growth ◽  
Old Growth Forest ◽  
Significant Difference ◽  
Young Growth

A litter-bag technique was used to measure decay rates and assess changes in organic and inorganic constituents of ponderosa pine (Pinusponderosa Laws.) needle litter during decomposition over a 2-year period in old- and young-growth forests in the Sierra Nevada of California. Rates of mass loss were among the lowest reported for temperate and boreal forests, with annual decomposition constants of about 0.08 and 0.18 year−1 for the old- and young-growth forests, respectively. Apparently, the temporal separation of warm temperatures and moist conditions found in Mediterranean-type climates severely limits decomposition in these coniferous forests. In the old-growth forest, comparison of estimates of tree nutrient uptake with net releases of nutrients from fine litter during their 1st year of decomposition suggests that recent litter fall potentially acts as a significant source of P, Mg, and K for tree uptake in this forest; in contrast, recently fallen litter acts as a net sink for N, S, and Ca. Despite initially lower indices of litter quality for litter originating from the old–growth relative to the young–growth forest, no significant difference in decomposition rates of these two litter age-classes was found when placed at either site. This result does not support the hypothesis that decreases in decomposition rates during forest development are driven by decreases in the quality of litter fall.

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