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Bried J.T.,Albany Pine Bush Preserve Commission | Jog S.K.,Northeastern State University | Matthews J.W.,University of Illinois at Urbana - Champaign
Ecological Indicators | Year: 2013

A common concern regarding the popular Floristic Quality Assessment (FQA) method is whether the site floristic quality scores change with natural temporal and site-specific variability. The more ignored question is whether this background variability will confound the index of human disturbance. Using non-forested seasonal wetlands in the northeastern United States, we tested if two common indices of site floristic quality (FQAI, Mean CoC) provide clear signals of site condition relative to gradients of wetland area and surface water depth, and consistent signals across time of year (early vs. late growing season), geomorphic setting (connected vs. isolated), and vegetation community type (pine barrens vernal pond, wet sedge meadow, shrub swamp). Mean CoC is the coefficient of conservatism (a qualitative estimate of species' sensitivity to human disturbance) averaged across the native and exotic taxa observed at a given site, and FQAI is the traditional Floristic Quality Assessment Index where Mean CoC is multiplied by square root of taxa richness. The FQAI did not linearly correspond to the site condition gradient and thus it could not be evaluated. Mean CoC was clearly associated with site condition, with no interference from wetland area or water level (based on computer-intensive resampling of linear model fit). Mean CoC also varied consistently with site condition between the surveys, geomorphic settings, and community types (based on computer-intensive resampling of linear model slope). However, connected wetlands showed inherently greater Mean CoC than isolated wetlands, suggesting a comparison of floristic quality between these categories would not be prudent. Overall this study suggests that FQA in the form of Mean CoC may withstand natural variability in certain non-forested wetland systems. Instead of assuming FQA is overly sensitive to natural variability, we recommend further efforts to identify situations in which FQA is robust. © 2013 Elsevier B.V. All rights reserved.

Bried J.T.,Albany Pine Bush Preserve Commission | Pellet J.,A. Maibach Sarl
Journal of Insect Conservation | Year: 2012

Occupancy has several important advantages over abundance methods and may be the best choice for monitoring sparse populations. Here we use simulations to evaluate competing designs (number of sites vs. number of surveys) for occupancy monitoring, with emphasis on sparse populations of the endangered Karner blue butterfly (Lycaeides melissa samuelis Nabokov). Because conservation planning is usually abundance-based, we also ask whether detection/non-detection data may reliably convert to abundance, hypothesizing that occupancy provides a more dependable shortcut when populations are sparse. Count-index and distance sampling were conducted across 50 habitat patches containing variably sparse Karner blue populations. We used occupancy-detection model estimates as simulation inputs to evaluate primary replication tradeoffs, and used peak counts and population densities to evaluate the occupancy-abundance relationship. Detection probability and therefore optimal design of occupancy monitoring was strongly temperature dependent. Assuming a quality threshold of 0. 075 root-mean square error for the occupancy estimator, the minimum allowable effort was 360 (40 sites × 9 surveys) for spring generation and 200 (20 sites × 10 surveys) for summer generation. A mixture model abundance estimator for repeated detection/non-detection data was biased low for high-density and low-density populations, suggesting that occupancy may not provide a reliable shortcut in abundance-based conservation planning for sparse butterfly populations. © 2011 Springer Science+Business Media B.V.

Kirchman J.J.,140 Cultural Education Center | Ralston J.,140 Cultural Education Center | Ralston J.,University at Albany | Gifford N.A.,Albany Pine Bush Preserve Commission
Wilson Journal of Ornithology | Year: 2011

We conducted mist-net surveys of migrating songbirds during fall migration 2007-2009 on the 1,300-ha Albany Pine Bush Preserve (APBP), a fire-managed inland pitch pinescrub oak (Pinus rigidaQuercus spp.) barren in east-central New York. We banded 244 migrating passerines from 32 non-resident species in 8,610 net/m/hr documenting use of northeastern pine barrens as stopover sites for passerines with diverse breeding ecologies. We estimated the breeding site origin of six species (a kinglet, four warblers, and a sparrow) using stable hydrogen isotope measurements from flight feathers. There was a broad range of isotope ratios within each species indicating a large catchment area extending several hundred kilometers north and west of the stopover site. Over half the birds originated >750 km from the APBP. We found no evidence for geographical structure of the timing of migration through APBP; slopes of regression lines for capture date versus hydrogen isotope ratio from feathers (δDf) were not statistically different from zero. This contrasts with previous isotope research that reports both leapfrog and chain migration patterns by different warbler species at stopover sites in the western United States. © 2011 by the Wilson Ornithological Society.

Bried J.T.,Albany Pine Bush Preserve Commission | Bried J.T.,Oklahoma State University | Strout K.L.,New England Interstate Water Pollution Control Commission | Portante T.,New England Interstate Water Pollution Control Commission
Northeastern Naturalist | Year: 2012

The floristic quality index is a widely used method for ecological condition assessments in the United States. The foundation of the index is the conservatism concept, which estimates a species' ecological sensitivity or propensity to occur in areas least altered by humans. Plant species are assigned coefficients of conservatism (CoC) where ruderal and exotic species receive the lowest scores, competitors and matrix species intermediate scores, and remnant-dependent species the highest scores. The method has spread to over half of the United States, but New York and New England still lack CoC coverage. With funding from the Environmental Protection Agency and using nine of the region's most experienced botanists, an effort was undertaken to select CoC for the complete vascular flora of each New England state and New York State. Frequency distributions and rank correlations of CoC varied widely among states, except that each flora contained a large proportion of exotic species. Few taxa were scored with low confidence, although CoC at the extreme ends of the scale tended to be scored with higher confidence than more intermediate CoC. Differences in mean CoC and other summary measures for two botanists working independently on the same state indicate estimator bias in the ranking process, and calls for additional expert opinions, more careful instruction, and calibration of botanists, or the use of objective scoring methods.

Gifford N.A.,Albany Pine Bush Preserve Commission | Deppen J.M.,Hudsonia Ltd. | Bried J.T.,Albany Pine Bush Preserve Commission
Landscape and Urban Planning | Year: 2010

Shrubland birds have become one of the most conservation-reliant avian groups in the Northeastern United States. Their contemporary distribution is restricted to regenerating commercial forests, utility rights-of-way, and other types of managed early-successional habitat. This study explored whether a highly fragmented urban pine barrens can have conservation value for shrubland birds. Specifically, we estimated the amount of core early-successional habitat available to shrubland birds in the Albany Pine Bush Preserve (East-central New York State) and quantified bird-habitat associations from systematic point count surveys. This 1255 ha urban preserve contains approximately 150 ha of core early-successional habitat dominated by pitch pine and scrub oaks. Eighty-two species, including 24 shrubland birds, were observed in one breeding season. Many of these birds have shown regional population declines and six are species of greatest conservation need in New York. Two shrubland species previously extirpated were common across the preserve, and on average shrubland species were similarly abundant to non-shrubland species. Several shrubland species were strongly associated with the limited early-successional habitat, and the prairie warbler is recommended as the best potential avian indicator for monitoring ecosystem health and management effectiveness in this globally rare pine barrens. Twenty years of ecosystem restoration, including prescribed fire and invasive plant management, is buffering the effects of fire suppression, habitat loss, and fragmentation on shrubland birds in this landscape. When managed appropriately, urban shrublands can provide suitable breeding habitat and may aid in the regional conservation of early-successional shrubland birds. © 2009 Elsevier B.V. All rights reserved.

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