Walker's Mammals of the World, 4th Edition, Ronald M. Nowak, John L. Paradiso. The Johns Hopkins University Press, Baltimore, Maryland (1983), 1xi, +1-568 (Vol. I), xxv+569-1362 (Vol. II). Price $65.00

A controversy exists in the Pacific Northwest of the United States between logging of old-growth coniferous forests and conservation of Northern Spotted Owl (Strix occidentalis caurina) populations. This species has a strong association with old-growth forests that also have economic value as timber. Research questions relevant to conservation of this species include how temporal trends in Northern Spotted Owl populations are influenced and how spatial configuration of old-growth forests affects these populations. To address these questions, we studied a population of marked Northern Spotted Owls on 95 territories in northwestern California from 1985 through 1994. We examined the mag- nitude of temporal and spatial variation in life history traits (survival, reproductive output, and recruitment), the effects of climate and landscape characteristics on temporal and spatial variation in these traits, respectively, and how this variation affected aspects of population dynamics. We used a components-of-variation analysis to partition sampling from process variation, and a model selection approach to estimate life history traits using capture- recapture and random-effects models. Climate explained most of the temporal variation in life history traits. Annual survival varied the least over time, whereas recruitment rate varied the most, suggesting a ''bet-hedging'' life history strategy for the owl. A forecast of annual rates of population change ( l), estimated from life history traits, suggested that Northern Spotted Owl populations may change solely due to climate influences, even with unchanging habitat conditions. In terms of spatial variation, annual survival on territories was positively associated both with amounts of interior old-growth forest and with length of edge between those forests and other vegetation types. Reproductive output was nega- tively associated with interior forest, but positively associated with edge between mature and old-growth conifer forest and other vegetation types. A gradient existed in territory- specific estimates of fitness derived from these life history estimates. This gradient suggested that a mosaic of older forest interspersed with other vegetation types promoted high fitness in Northern Spotted Owls. Habitat quality, as defined by fitness, appeared to buffer variation in annual survival but did not buffer reproductive output. We postulated that the magnitude of l was determined by habitat quality, whereas variation of l was influenced by recruitment and reproductive output. As habitat quality declines, variation in l should become more pronounced.

/pdf/climate-habitat-quality-and-fitness-in-northern-spotted-owl-53cuekoyx8.pdf

Climate, habitat quality, and fitness in northern spotted owl populations in northwestern california

/pdf/xin-siiguo-ji-xue-shu-za-zhi-forest-ecology-and-management-3gwqz4yhln.pdf

新しい国際学術雑誌"Forest Ecology and Management"の発行

This paper reviews and compares the effects of forest fire and timber harvest on mamma- lian abundance and diversity, throughout successional time in the boreal forest of North America. 2. Temporal trends in mammal abundance and diversity are generally similar for both harvested and burned stands, with some differences occurring in the initiation stage (0- 10 years post disturbance). 3. Small mammals and ungulates are most abundant immediately post disturbance, and decrease as stands age. Lynxes and hares utilize mid-successional stands, but are rare in young and old stands. Bats, arboreal sciurids and mustelids increase in abundance with stand age, and are most abundant in old growth. 4. Substantial gaps in the data exist for carnivores; the response of these species to fire and harvest requires research, as predator-prey interactions can affect mammal community struc- ture in both early and late successional stages. 5. The lack of explicit treatment of in-stand forest structure post disturbance, in the reviewed literature made comparisons difficult. Where forest structure was considered, the presence of downed woody material, live residual trees and standing dead wood were shown to facilitate convergence of mammal communities to a pre-disturbance state for both disturbance types. 6. Mammalian assemblages differed considerably between successional stages, emphasizing the importance of maintaining stands of each successional stage on the landscape when implementing forest management strategies.

/pdf/the-response-of-mammals-to-forest-fire-and-timber-harvest-in-1qay64y73g.pdf

The response of mammals to forest fire and timber harvest in the North American boreal forest

Properties and Management of Forest Soils

The northern flying squirrel (Glaucomys sabrinus) is the primary prey of northern spotted owls (Strix occidentalis caurina) and California spotted owls (S. o. occidentalis) throughout much of the owls' ranges. Flying squirrel abundance patterns, however, are poorly documented. Using capture-recapture techniques to estimate density, we compared flying squirrel densities among 3 types of fir (Abies spp.) forests in Lassen National Forest, northeastern California. We compared densities between 3 each of old and shelterwood-logged fir stands in 1990 and among 4 each of old, shelterwood, and young fir stands in 1991-92. Shelterwood stands had been logged and had undergone site preparation 5 years prior to our study. In 1990 flying squirrel density was greater in old (? = 2.76 squirrels/ha, SE = 0.55) than in shelterwood (? = 0.31 squirrels/ha, SE = 0.11) stands (P = 0.005). In 1991-92 density varied (P = 0.001) among the 3 stand types, averaging 3.29 squirrels/ha (SE = 0.63) in old, 2.28 squirrels/ha (SE = 0.18) in young, and 0.37 squirrels/ ha (SE = 0.17) in shelterwood stands. Body mass of adult males and females and recapture rate did not differ (M, P = 0.438; F, P = 0.983; P = 0.218, respectively) between old and young stands, and percent juveniles captured was greater (P = 0.052) in old than in young stands. Diet analyses were consistent with other studies and indicated that sporocarps of hypogeous fungi were a common food source. Frequency of hypogeous sporocarps was correlated (r s = 0.860, P < 0.001) with flying squirrel density, but cavity density and understory cover were not (P = 0.344 and 0.217, respectively). Flying squirrels were not old-growth specialists; however, low densities in shelterwood stands suggest that heavy logging and intensive site preparation negatively affected flying squirrel populations.

Northern flying squirrel densities in fir forests of northeastern California

The objectives of our study were to determine the effects of commercial thinning and broadcast burning on sporocarp production of hypogeous ectomycorrhizal (HEM) fungi. At two sites in northeastern California, Jennie Springs (JS) and Swain Mountain (SM), we compared HEM sporocarp production among units that had been heavily thinned, moderately thinned, and unthinned. At one of those sites, JS, we also compared sporocarp production between units that had been broadcast burned and units left unburned. Sporocarps were sampled in 1992, 10 years after thinning and 9 years after burning occurred at JS, and 17 years after thinning occurred at SM. Total relative frequency and biomass of sporocarps did not differ significantly among thin levels at either site, or between burn levels at JS. There was, however, significant association between thin level and frequencies of the most common genera at JS, suggesting that thinning significantly affected the composition of HEM fungi. The association between burn level and...

https://www.fs.fed.us/psw/publications/watersj/waters4.pdf

The effects of thinning and broadcast burning on sporocarp production of hypogeous fungi

https://www.fs.fed.us/psw/publications/watersj/waters2.PDF

Truffle production in old-growth and mature fir stands in northeastern California

Zabel and Waters "Food preferences of captive northern flying squirrels from the Lassen National Forest in northeastern California." Northwest Science. 1997; 71(2): 103-107

Food preferences of captive northern flying squirrels from the Lassen National Forest in northeastern California

We compared abundances of seven species of forest rodents among three types of fir ( Abies concolor and A. magnifica ) forest: unlogged old-growth, unlogged mature, and shelter-wood-logged old-growth. Small mammals were livetrapped during summers 1991 and 1992 in four grids within each type of forest; grids were located in the Lassen National Forest in northeastern California. Shelterwood-logged forests had been logged 6–7 years previously. Differences in capture rates between unlogged, old-growth and shelterwood-logged, old-growth forests suggest that logging led to significant increases in populations of golden-mantled ground squirrels ( Spermophilus lateralis ), yellow pine chipmunks ( Tamias amoenus ), and lodgepole chipmunks ( Tamias speciosus ) but may have led to reduced populations of western red-backed voles ( Clethrionomys californicus ). Capture rates of Douglas' squirrels ( Tamiasciurus douglasii ), Allen's chipmunks ( Tamias senex ), and deer mice ( Peromyscus maniculatus ) did not differ significantly between unlogged and shelterwood-logged forests. Capture rate of T. douglasii was significantly greater in mature forests than in old-growth forests in 1992, but we did not detect significant differences between old-growth and mature forests for the other six species. These results illustrate how opening of the canopy and disturbance of the forest floor can lead to significant changes in patterns of abundance of forest rodents.

https://www.fs.fed.us/psw/publications/watersj/waters1.PDF

Jeffrey R. Waters

Papers

Northern flying squirrel densities in fir forests of northeastern California

The effects of thinning and broadcast burning on sporocarp production of hypogeous fungi

Truffle production in old-growth and mature fir stands in northeastern California

Food preferences of captive northern flying squirrels from the Lassen National Forest in northeastern California

Abundances of Small Mammals in Fir Forests in Northeastern California