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Maintaining Wildlife Habitat in Southeastern Alaska: Implications of New Knowledge for Forest Management and Research

Maintaining Wildlife Habitat in Southeastern Alaska: Implications of New Knowledge for Forest Management and Research Thomas A. Hanley, Winston P. Smith, and Scott M. Gende PNW Research Station, Juneau, AK Purposes of this report

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Maintaining Wildlife Habitat in Southeastern Alaska: Implications of New Knowledge for Forest Management and Research

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  1. Maintaining Wildlife Habitat in Southeastern Alaska: Implications of New Knowledge for Forest Management and Research Thomas A. Hanley, Winston P. Smith, and Scott M. Gende PNW Research Station, Juneau, AK

  2. Purposes of this report • Provide a brief background of studies that were initiated as follow-up to TLMP. • Review major findings from those studies. • Identify information needs and directions for future research.

  3. TLMP Follow-up Studies • Evolutionary diversity of endemic small mammals • Ecology of endemic populations of flying squirrel, red-backed vole, northern goshawk, and marbled murrelet • Ongoing studies of American marten and Alexander Archipelago wolf • Bird communities of old-growth forests (Alternatives to Clearcutting Study)

  4. Evolutionary diversity and taxonomy of endemic small mammals • Early expeditions surveyed only 22 of the named islands and identified 27 endemic mammal taxa. • Recent work has surveyed 87 islands and documented that the mammal fauna is much more complex than was previously realized. • The fauna is nested and comprised of multiple elements with discontinuities and regional assemblages reflecting different histories. • This is an especially rich region for endemism in its small mammal fauna.

  5. Northern flying squirrel • Distribution is disjunct – Prince of Wales subspecies was focus of study. • Associated with old-growth forests in the Pacific Northwest. Forest structure (old growth) and fragmentation (re dispersal) were main causes for concern on Tongass. This is an arboreal species. • Results from POW indicated densities among the highest reported in North America. • Densities in “mixed-conifer” forests were less than in old growth but comparable to old-growth Douglas fir in Pacific Northwest. • No evidence of mixed conifer forest being “sink” habitat.

  6. Southern red-backed vole • Occurs as 4 endemic subspecies on Tongass – Wrangell Island subspecies was focus of study. • Associated with old-growth forests in the Pacific Northwest. Forest structure (old growth) and fragmentation (re dispersal) were main causes for concern on Tongass. This is a ground-dwelling species. • Results from Wrangell Island indicated highest densities in old-growth forest and very low densities in peatland/mixed-conifer forest. • Thinned young-growth stands (20-25 yrs old) also were very productive of voles, similar to old growth forests.

  7. Northern goshawk • Two principal studies: nesting area and movements (Flatten et al. 2001), and dietary items (Lewis 2001) • Nesting sites changed often among years. “Nesting areas” were 0.5-3.2 km in diameter. • Diets varied greatly among nests during the breeding season and within nests between years, but birds always constituted a greater proportion of diet than did mammals (78 vs 22% of deliveries). • Current protective measures are “nest-based,” but goshawks tend not to use the same nest in consecutive years. • Although considered for MIS, logistical difficulties in monitoring goshawks make them impractical for MIS.

  8. Marbled murrelet • 1997 TLMP conservation strategy involved protection of near shore, low-elevation, old-growth forests for nesting habitat. • Smith & Harke (2001) provided guidelines for sample sizes needed for monitoring population trends. • Whitworth et al. (2000) followed radio-collared birds and found large distances between at-sea feeding areas and inland nesting areas (up to 124 km). • Nesting habitat does not appear to be limiting now or in the foreseeable future.

  9. American marten • Cavities in large boles of trees and snags, hard downed logs, and beneath tree roots are most important for natal dens and resting areas.  Large, old trees are important. • Population size on NE Chichagof fluctuated 4-fold during 10 years of study, with 90% of the variation accounted for by abundance of rodents (mice, voles, squirrels). • More study of marten is needed in SE AK, beyond the NE Chichagof area, before findings can be generalized. • Trapping is potentially a major complication in using marten population dynamics for MIS.

  10. Alexander Archipelago wolf • Research has centered on the Prince of Wales Island complex (POW and 10 nearby islands). • Strong inverse relationship between wolf home range size and proportion of “critical winter habitat for deer.” Strong positive relationship between wolf pack size and same (“c.w.h. for deer”). • Wolves move freely between islands; their ranges may shift significantly over time. This complicates monitoring populations. • Hunting/poaching was the major factor of mortality for wolves (89%). •  Deer populations and road access are predominant factors of productivity and mortality in wolf populations. • Current conditions are misleading, as clearcuts will become young-growth forest in near future, and deer habitat will decline greatly.

  11. “Alternatives-to-clearcutting” study • Focus has been on bird communities. • Pretreatment descriptions (old-growth stands) at Hanus Bay, Portage Bay, and Lancaster Cove. Along with Smith’s RNA survey, we have broad base of descriptions of bird communities of old-growth forests in SE AK. • Study of nest predation indicated that forest “edge” may increase predation rates, depending on nest predators in surrounding habitats (i.e., a community-level response). • Post-treatment responses are yet to be seen. However, future focus will shift to hypothesis-testing, rather than monitoring.

  12. Future management environment • Major changes since the 1997 TLMP: • Huge decline in demand and harvest of timber since the pulp mills closed • “Roadless Rule” implementation? • Huge increase in tourism •  Changing economy in SE AK, especially from timber to recreation-dominated

  13. 5 greatest challenges for wildlife habitat on the Tongass • Increasing management emphasis on young-growth forests • Designing conservation strategies for old-growth forests • Finding timber-harvest alternatives to clearcutting • Managing habitat for “subsistence” harvest of black-tailed deer • Minimizing effects of tourism on sensitive species of wildlife

  14. Future research, development, and application • 1997 TLMP conservation strategy focused on MIS and old-growth reserves. • We suggest future RD&A focus on plant and animal communities and management of vegetation to achieve specific objectives for wildlife habitat.

  15. 5 Major areas of future RD&A • Plant and animal communities of young-growth forests • Old-growth forest reserves • Alternatives to clearcutting • Black-tailed deer habitat and harvest • Effects of tourism on selected species

  16. Young-growth forests • Silviculture and understory vegetation – Principal need is promoting a diverse and productive understory, especially the herb component. • Autecology of major understory species (including hemlock), combined with silviculture effects on understory environment • Tongass adaptive management studies – thinning (precommercial and commercial), pruning, red alder • Wildlife communities in relation to stand structure – both young-growth and older stands (re partial harvest systems).

  17. Old-growth forests • Most work to date has focused on all-aged stands, with gap-phase succession. • Recent work has shown that much Tongass “old-growth” is multi-cohort stands, resulting from large-scale wind disturbance. We know very little about community patterns and stand dynamics in these stands, yet they have major implications for conservation reserves and “long rotations” (200 yrs) in TLMP. • Greatest needs for wildlife community research relate to the importance of size and landscape distribution of old-growth reserves – especially re dispersal and population viability of selected focal species.

  18. Alternatives to clearcutting • Recent retrospective studies of individual-tree selection cutting have shown that partial cutting may have minimal effects on forest understory vegetation – i.e., parallels gap-phase succession. • Future research should focus on processes involved in community response to cutting pattern, especially role of patch size and “edge” in vegetation and animal response. • Other key processes include dispersal by small mammals, role of scale in habitat heterogeneity for animal community structure, fruit production in relation to sunlight (gap size), snow interception in relation to canopy structure, etc.

  19. Black-tailed deer • Principal game species for recreation and subsistence hunters, and principal prey for Alexander Arch. wolf • Current large-scale habitat evaluation models (e.g., Habitat Suitability Index) are based on deer behavior, which is site, time, and density dependent. • Current nutritional models for habitat evaluation are limited to the stand-level scale of analysis. They need to be expanded to applicability at large spatial scales (e.g., landscape-level analyses). • Analytical techniques for monitoring population status and trends are needed for subsistence harvest and interactions with wolves.

  20. Effects of tourism • Flight-seeing impacts (especially helicopters) on mountain goats – Most likely effects would involve scaring mountain goats away from favorite habitats (cliffy terrain), thereby decreasing foraging efficiency and increasing susceptibility to wolves,  decrease in lamb survival. • Brown bear viewing – disruption of bears from favorite salmon-fishing areas • Both of above topics (and others) are entirely speculative and are very difficult to measure effects in biologically meaningful terms. Cooperation with ADF&G would be very important.

  21. Conclusions • SE AK has a high potential for endemism in its mammal fauna, and those systematics are only recently beginning to be known. More work is needed here. • However, the 2 potentially “old growth dependent” species studied intensively (flying squirrels and red-backed voles) do not seem to be so dependent on old growth as was hypothesized – flying squirrels because of low-volume, scrub forest; red-backed voles because of precommercial thinnings. • Challenges will continue, though, because of the legacy of 4 decades of clearcutting (e.g., backlog in thinning, etc.).

  22. Conclusions (cont.) • Maintaining viable and productive populations of small mammals also has important implications for northern goshawk and American marten, both of which may be prey-limited in SE AK. Active young-growth management likely will be important to both those species. • Regardless of future management environment, there is an urgent need to develop sampling protocols for inventory and monitoring of wildlife populations – to adequately document biological diversity, evaluate conservation strategies, and conduct effectiveness monitoring.

  23. Conclusions (cont.) • New challenges needing RD&A are especially great in 5 areas: • Intensive, even-aged forest management • Old-growth forest reserves • Alternatives to clearcutting • Black-tailed deer habitat & population management • Tourism impacts on sensitive species

  24. Conclusions (cont.) We propose that most of that RD&A be done in collaboration between the PNW Station (ecological processes and new applications) and the Tongass National Forest (especially through adaptive management experiments and large-scale treatments/applications).

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