AMNHForestryBirdsPos ter Apr27th2006

Logging impacts on birds in New York: A role for private forest stewardship in bird conservation : 

Logging impacts on birds in New York: A role for private forest stewardship in bird conservation 1Audubon New York, 159 Sapsucker Woods Road, Ithaca, NY, USA 2United States Fish and Wildlife Service, 52 Avenue A, Turners Falls, MA, USA (current address) 3Consulting in the Public Interest, Box 220, Lambertville, NJ, USA 4Audubon New York, 200 Trillium Lane, Albany, NY, USA Abstract Timber harvesting can have significant impacts on bird communities as a result of changes in habitat structure. We conducted bird and vegetation surveys in 71 northern hardwood stands in upstate New York from 1999-2001 to quantify avian responses to logging as it is conducted on private lands. In our study, we analyzed responses of three ecological habitat groups of bird species (based on previously published studies): generalists, those that prefer “early” forests with relatively few large trees, and those that prefer more “mature” forests. In addition, we analyzed the responses of individual species and all species pooled. Forest stands were grouped using cluster analysis of residual basal area and tree size into four categories resulting from their recent management: uncut or lightly thinned (category A), moderate partial harvest (category B), heavy partial harvest (category C), and clearcut (category D). Early-forest birds were more abundant in more disturbed habitats and were more habitat-specific than were mature-forest birds, which showed considerable overlap among forest categories in terms of both relative abundance and richness. For example, the abundance and richness of mature-forest birds were very similar in categories A and B and only slightly lower in C, whereas early-forest birds rapidly increased in abundance and richness across categories from A to D. Neither abundance nor richness of the generalists differed significantly among forest categories. The use of ecological habitat groups and forest condition categories simplified our findings and provided a meaningful way to describe to forestry professionals and landowners how birds responded to logging. These results provided the basis of a forestry education initiative promoting sustainable, wildlife-friendly forestry that targets private forest owners, who control nearly 85% of New York’s forests. The education initiative was designed and implemented by a diverse group of stakeholders, including agency, non-profit, industry, and landowner representatives. Objectives Describe breeding bird community of recently managed northern hardwood forests in New York State along a gradient of harvest intensity Develop outreach materials and strategies for communicating results to private forest owners and professional foresters Methods Study Design Study areas: Unfragmented regions of the Adirondacks and Appalachian Plateau (Catskills and Southern Tier) 71 northern hardwood forest stands sampled from 1999-2001 Stands represent a gradient of harvest intensity, including unmanaged, partially harvested, and clearcut stands In harvested stands, logging had taken place within the previous 2-5 yrs Vegetation Sampling 10-ha (25-acre) study plot in each stand 12-15 randomly located vegetation sample points Basal area plots Trees: dead or alive, species, DBH, cavities Over-, mid-, and understory and ground cover estimated Coarse woody debris measured Canopy height Slope, aspect, elevation Bird Community Sampling Conducted at 6 points per stand (selected from the vegetation sample points such that bird points were at least 150m apart and 100m from the stand edge) 10-min point counts conducted between 5:00 and 10:00am 3 visits during June Data Analysis Stands grouped using cluster analysis into 4 forest condition categories (Table 1, Figure 1) Bird species assigned (a priori using meta-analysis of previously published studies) into three ecological habitat groups according to the relationship between their relative abundance and stand basal area (Table 2) ANOVA (Duncan’s Multiple Comparison Test) used to determine significant differences of bird group abundance and richness among forest condition categories (Figures 2-5) BURGER, MICHAEL1; Mitschka Hartley1,2; Jan Beyea3; Graham Cox4 Results Mature (or lightly thinned) Moderate Partial Harvest Heavy Partial Harvest Clearcut Figure 1. Graphic depictions of average stands from the four forest condition categories resulting from a cluster analysis of 71 northern hardwood forest stands. Table 1. Habitat characteristics of forest condition categories. (B) (C) Moderate Heavy (A) Partial Partial (D) Mature Harvest Harvest Clearcut Timber stocking ~100% 70-80% 40-60% <20% Canopy cover >75% >75% <50% <25% Ground cover 35% 45% 55% 75% Basal area (sq.ft.) 100 77 54 15 Table 2. Alphabetical listing of birds in each of the three ecological habitat groups determined through meta-analysis of previously published studies (alpha=0.2). * denotes species of conservation concern (PIF 2002). Prefer “early” forests American Goldfinch American Redstart* American Robin Black-and-white Warbler* Brown-headed Cowbird Canada Warbler* Chipping Sparrow Common Yellowthroat Chestnut-sided Warbler* Eastern Towhee* Field Sparrow* Gray Catbird* House Wren Indigo Bunting* Magnolia Warbler Mourning Warbler Northern Flicker* Olive-sided Flycatcher* Rose-breasted Grosbeak* Ruffed Grouse* Song Sparrow Veery* White-throated Sparrow Yellow Warbler Generalists American Crow Baltimore Oriole* Blue Jay Common Grackle Dark-eyed Junco Downy Woodpecker Eastern Phoebe Great Crested Flycatcher* Hooded Warbler* Nashville Warbler Northern Parula* Northern Waterthrush Pine Siskin Pine Warbler Pileated Woodpecker Prairie Warbler* Purple Finch* Red-breasted Nuthatch Red-bellied Woodpecker Warbling Vireo Yellow-bellied Flycatcher Yellow-billed Cuckoo Yellow-rumped Warbler Yellow-throated Vireo* Prefer “mature” forests Blackburnian Warbler* Black-capped Chickadee Black-throated Blue Warbler* Black-throated Green Warbler* Blue-headed Vireo* Brown Creeper Eastern Wood-Pewee* Golden-crowned Kinglet Hairy Woodpecker Hermit Thrush Least Flycatcher Ovenbird Red-eyed Vireo Scarlet Tanager* Swainson’s Thrush White-breasted Nuthatch Winter Wren Wood Thrush* Yellow-bellied Sapsucker* D A B C Figure 2. Relative abundance of breeding birds among four forest condition categories. Error bars represent standard deviation. Within a color series of bars, different letters indicate statistically significant differences among categories (alpha=0.1). a a b c a a a a a a a b Figure 3. Species Richness of breeding birds among four forest condition categories. Error bars represent standard deviation. Within a color series of bars, different letters indicate statistically significant differences among categories (alpha=0.1). a b c d a a a a a,b a b c Figure 5. Relative abundance of breeding birds considered to be species of conservation concern in New York, as determined by Partners In Flight, among forest condition categories. Error bars represent standard deviation. Different letters in bars indicate statistically significant differences among categories (alpha=0.1). a a,b b,c c Figure 4. Relative abundances of three “mature” forest species, showing variation of patterns among individual species across forest condition categories. Error bars represent standard deviation. BLBW is Blackburnian Warbler, BTNW is Black-throated Green Warbler, BTBW is Black-throated Blue Warbler. Conclusions Northern hardwood forests in unfragmented regions of New York, managed at various intensities, support many breeding birds at relatively high abundances Different breeding bird “communities” are associated with each forest condition category Most species are abundant in more than one category No species was restricted to a single category Species of conservation concern are relatively more abundant and rich in forests managed more intensively Forest management can benefit the conservation of birds in New York Outreach The New York Forest Biodiversity Partnership formed to translate and communicate the results of this study to private forest owners, forestry professionals, and forestry students in New York State. The goals of the partnership are: To share information about the effects of logging on non-game wildlife To promote sustainable forest management in New York Outreach mechanisms include: Publication of Wildlife and Forestry in New York Northern Hardwoods: A Guide for Forest Owners and Managers (Figure 6) Conducting a series of workshops for forest landowners, Master Forest Owners, forestry students, private consulting foresters, state foresters, and loggers Partners include: Audubon New York Consulting in the Public Interest Cornell University Empire State Forest Products Association International Paper Company New York Forest Owners Association New York Institute of Consulting Foresters New York State Dept. of Environ. Cons. Northeastern Loggers Association Paul Smiths College SUNY-Environmental Science & Forestry United States Fish & Wildlife Service Funding for this project was provided by: New York State Biodiversity Research Institute Park Foundation United States Forest Service Figure 6. Cover of the forestry guide.