SnagPRO: snag and tree sampling and analysis methods for wildlife

Snag dynamics in post-harvest landscapes of western Newfoundland balsam fir-dominated boreal forests

Availability of standing trees for large cavity-nesting birds in the eastern boreal forest of Québec, Canada

The overwhelming majority of information on historical forest conditions in western North America comes from public lands, which may provide an incomplete description of historical landscapes. In this study we made use of an archive containing extensive timber survey data collected in the early 1920s from privately owned forestland. These data covered over 50,000ha and effectively represent a 19% sample of the entire area. The historical forest conditions reconstructed from these data fit the classic model of frequent-fire forests: large trees, low density, and pine-dominated. However, unlike other large-scale forest reconstructions, our study area exhibited relatively low overall variability in forest structure and composition across the historical landscape. Despite having low variability, our analyses revealed evidence of biophysical controls on tree density and pine fraction. Annual climatic variables most strongly explained the range in historical tree densities, whereas historical pine fraction was explained by a combination of topographic and climatic variables. Contemporary forest inventory data collected from both public and private lands within the same general area, albeit not a direct remeasurement, revealed substantial increases in tree density and greatly reduced pine fractions relative to historical conditions. Contemporary forests exhibited a far greater range in these conditions than what existed historically. These findings suggest that private forestland managed with multiaged silviculture may be similar to public forestland with respect to departure in forest structure and compositions from that of historical forests. However, there may be differences between management objectives that favor timber production, more typical on private lands, vs. those that favor restoration, increasingly supported on public lands.

Early impacts of fire suppression in Jeffrey pine – Mixed conifer forests in the Sierra San Pedro Martir, Mexico

:Remnants of old forests left on the landscape following forest harvesting, especially corridors, provide benefits of connectivity and facilitation of movement or dispersal, which may be hindered by the presence of edges. Our objective was to determine the extent of edge influence on forest structure in these forest remnants in black spruce boreal forest. We sampled canopy cover and the density of trees, snags, and logs along clearcut edge–forest gradients in large forest patches, cutblock separators, and riparian buffers. The distance-of-edge influence was determined by comparing values at different distances from the edge to values in interior forest using randomization tests. Forest remnants had lower live tree density and canopy cover and higher mortality and windthrow than interior forest. Distance-of-edge influence on forest structure extended 10–30 m from the edge, and was slightly more extensive into cutblock separators where two edges are in close proximity, but was less extensive in riparian buffers, possibly due to the presence of stable internal edges near the stream. Because of edge influence, structure near the edges of forest remnants and across narrow corridors is modified; wider corridors would be required to provide a core habitat of interior forest conditions.

We investigated the occurrence of, and relationships among, snags and cavity-nesting birds in the rapidly urbanizing region around Seattle, Washington in 2001 and 2002. We measured the density of snags in 49 sites (1-km2 “suburban landscapes” that included built and forested portions), and determined the diameter, height, decay status, and species of individual snags. We spot-mapped territories and observed nests of cavity-nesting birds at a stratified, random subsample of 13 sites. Snags, especially red alder (Alnus rubra), were abundant in sites' forested portions, but rare in the built portions. Snag density was positively correlated with density of live trees. Snags in built versus forested portions were similar in all attributes except decay, which was more advanced in forested areas. In the oldest suburbs (60–80 years old), snags in forested portions were larger, more decayed, and more likely to have broken tops than those in younger suburbs (2–20 years old). Cavity-nesting bird species richness and equity of individuals per species was highest in suburban landscapes where remaining forest was not fragmented, but adjacent to highly intermixed urban and urban-forest land covers. Suburban landscapes with highly interspersed land covers had higher densities of Black-capped Chickadees (Poecile atricapillus), Red-breasted Nuthatches (Sitta canadensis), Northern Flickers (Colaptes auratus) and Downy Woodpeckers (Picoides pubescens); suburban landscapes with higher percentages of forest had higher densities of Brown Creepers (Certhia americana), Chestnut-backed Chickadees (Poecile rufescens), Pileated (Dryocopus pileatus) and Hairy Woodpeckers (Picoides villosus). Red-breasted Sapsucker (Sphyrapicus ruber) densities were positively correlated only with the density of snags. All study sites had low bird densities compared to wildlands, presumably due to the relative lack of live trees and snags. Cavity-nesting birds bred successfully in all landscapes; seven of the nine species produced fledglings in >50% of their nesting attempts. Snags important for nesting were larger in diameter, taller, and more decayed than expected based on availability. Snags with active nests also had evidence of previous use, fungal conks, broken tops, and substantial bark. Efectos de la Expansión Urbana sobre la Abundancia y la Productividad de Aves que Nidifican en Cavidades Resumen. Durante el 2001 y 2002, investigamos la presencia de, y la relación entre, troncos muertos y aves que nidifican en cavidades en los alrededores de Seattle (Washington), una región que está urbanizándose rápidamente. Medimos la densidad de troncos en 49 sitios (1-km2 de “paisajes suburbanos” que incluyeron ambientes edificados y bosques) y determinamos el diámetro, altura, estado de descomposición y especie de troncos individuales. Mapeamos los territorios mediante registros puntuales y observamos los nidos de aves que nidifican en cavidades en una sub-muestra estratificada y al azar de 13 sitios. Los troncos, especialmente de Alnus rubra, fueron abundantes en las áreas con bosque, pero raros en las áreas edificadas. La densidad de troncos se correlacionó positivamente con la densidad de árboles vivos. Los troncos de las áreas edificadas y de las áreas con bosque fueron similares en todos sus atributos excepto en su descomposición, que fue más avanzada en los sitios boscosos. En los suburbios más viejos (60–80 años), los troncos en las áreas con bosque fueron más grandes, estuvieron más descompuestos y presentaron mayor probabilidad de tener sus extremos rotos que aquellos presentes en los suburbios más nuevos (2–20 años). La riqueza de especies que nidifican en cavidades y la equitatividad de individuos por especie fueron mayores en los paisajes suburbanos donde el bosque remanente no estaba fragmentado, sino adyacente a coberturas con una gran mezcla de sitios urbanos y sitios en la transición bosque-ciudad. Los paisajes suburbanos con coberturas ampliamente entremezcladas presentaron mayores densidades de Poecile atricapillus, Sitta canadensis, Colaptes auratus y Picoides pubescens; los paisajes suburbanos con porcentajes más altos de bosque presentaron mayores densidades de Certhia americana, Poecile rufescens, Dryocopus pileatus y Picoides villosus. Las densidades de Sphyrapicus ruber sólo se correlacionaron positivamente con la densidad de troncos. Todos los sitios de estudio tuvieron bajas densidades de aves comparados con áreas silvestres, debido presumiblemente a la carencia relativa de árboles vivos y troncos. Las aves que nidifican en cavidades criaron con éxito en todos los paisajes; siete de las nueve especies produjeron volantones en >50% de sus intentos de nidificación. Los troncos importantes para nidificar fueron más grandes en diá metro y altura y estuvieron más descompuestos que lo esperado con relación a su disponibilidad. Los troncos con nidos activos también presentaron evidencias de uso previo, deformaciones producidas por hongos, copas rotas y bastante corteza.

We provide efficient and accurate methods for sampling snags and large trees on a landscape to conduct compliance and effectiveness monitoring for wildlife in relation to the habitat standards and guidelines on National Forests. Included online are the necessary spreadsheets, macros, and instructions to conduct all surveys and analyses pertaining to estimation of snag and large tree densities and distributions at the subwatershed scale. The methods focus on optimizing sampling effort by choosing a plot size appropriate for the specific forest conditions encountered. Two methods are available for density analysis. Method one requires sampling until a desired precision level is obtained for a density estimate. Method two is intended for use in areas that have low snag densities compared to Forest plan targeted densities. After taking a minimum of 60 samples, one may test for a significant difference between the estimated and targeted densities. In addition, data can be used to calculate a distribution index. The value obtained from the distribution index indicates whether the current distribution of target snags and large trees across a subwatershed is adequate to meet the habitat needs of territorial cavity-nesters and other wildlife species. Wildlife use also may be evaluated.

Operational resilience in western US frequent-fire forests

Area-based fishery management and ecosystem-based management strategies are considered beneficial marine resource management tools, but they require finite information about the structure and function of ecosystems to evaluate populations and describe the effects of fishing on ecosystems. The required information is not likely to be obtained from sporadic, fishery-dependent data collected from data-poor fisheries, and funding constraints preclude extensive fishery-independent surveys. This situation has led to an interest in relating or combining information from a variety of disparate sampling methods. From 2003 to 2006, we investigated the relationships between estimates of catch per unit effort (CPUE) and the abundance of fishes generated from typical nearshore commercial fishing operations and estimates of density and abundance derived from scuba surveys in the same locations. The relationships between CPUE and the density estimates derived from different sampling methods were found to be statistically significant in the case of many of the common species sampled across sites in Carmel Bay, California. The compounding effects of within-sample variance and the error associated with the regression equations, however, would result in poor confidence in the values translated from one sampling method to another. Different sampling methods may provide reasonable estimates of population trends, but they are sufficiently different and variable as to preclude the use of a scaling factor to standardize population estimates among sampling methods. Also, the differences in species composition (i.e., relative CPUE or density among species) produced by each sampling method were significant and were also affected by habitat relief and sample depth. Nonetheless, our results suggest the value of a cost-benefit analysis that would allow managers to design optimal sampling strategies for characterizing CPUE relationships within a region of interest. A sampling program that benefits from the complementary strengths of fishing gear and scuba sampling will probably result in the most comprehensive description of nearshore fish assemblages.

AimLarge trees (d.b.h. ≥ 70 cm) store large amounts of biomass. Several studies suggest that large trees may be vulnerable to changing climate, potentially leading to declining forest biomass storage. Here we determine the importance of large trees for tropical forest biomass storage and explore which intrinsic (species trait) and extrinsic (environment) variables are associated with the density of large trees and forest biomass at continental and pan‐tropical scales.LocationPan‐tropical.MethodsAboveground biomass (AGB) was calculated for 120 intact lowland moist forest locations. Linear regression was used to calculate variation in AGB explained by the density of large trees. Akaike information criterion weights (AICc‐wi) were used to calculate averaged correlation coefficients for all possible multiple regression models between AGB/density of large trees and environmental and species trait variables correcting for spatial autocorrelation.ResultsDensity of large trees explained c. 70% of the variation in pan‐tropical AGB and was also responsible for significantly lower AGB in Neotropical [287.8 (mean) ± 105.0 (SD) Mg ha−1] versus Palaeotropical forests (Africa 418.3 ± 91.8 Mg ha−1; Asia 393.3 ± 109.3 Mg ha−1). Pan‐tropical variation in density of large trees and AGB was associated with soil coarseness (negative), soil fertility (positive), community wood density (positive) and dominance of wind dispersed species (positive), temperature in the coldest month (negative), temperature in the warmest month (negative) and rainfall in the wettest month (positive), but results were not always consistent among continents.Main conclusionsDensity of large trees and AGB were significantly associated with climatic variables, indicating that climate change will affect tropical forest biomass storage. Species trait composition will interact with these future biomass changes as they are also affected by a warmer climate. Given the importance of large trees for variation in AGB across the tropics, and their sensitivity to climate change, we emphasize the need for in‐depth analyses of the community dynamics of large trees.

Abstract. The Brown-headed Nuthatch (Sitta pusilla) is listed as a species of conservation concern throughout most of its range. Forest conditions that support the imperiled Red-cockaded Woodpecker (Picoides borealis) are thought to provide excellent habitat for the nuthatch, but ambiguity exists because the nuthatch has disappeared from some areas where the woodpecker persists. We studied Brown-headed Nuthatches in two forest types that spanned an environmental gradient in central Florida and also differed in terms of forest structure and the presence of woodpeckers. Sandhill forests had mature timber that supported a large woodpecker population (∼70 territories); flatwood forests were dominated by younger pines and supported no Red-cockaded Woodpeckers. We used repeated surveys incorporating broadcast vocalizations and patch-occupancy analysis to assess variation in nuthatch occupancy and detection in relation to forest type, four structural covariates (snag density, basal area of pines and hardwoods, a...

To reflect the requirement of section 4 of the Wastes Isolation Pilot Plant Land Withdrawal Act (the Act) (Public Law 102-579), this land management plan has been written for the withdrawal area consistent with the Federal Land Policy and Management Act of 1976. The objective of this document, per the Act, is to describe the plan for the use of the withdrawn land until the end of the decommissioning phase. The plan identifies resource values within the withdrawal area and promotes the concept of multiple-use management. The plan also provides opportunity for participation in the land use planning process by the public and local, State, and Federal agencies. Chapter 1, Introduction, provides the reader with the purpose of this land management plan as well as an overview of the Waste Isolation Pilot Plant. Chapter 2, Affected Environment, is a brief description of the existing resources within the withdrawal area. Chapter 3, Management Objectives and Planned Actions, describes the land management objectives and actions taken to accomplish these objectives.

Toma T, Warsudi, Osone Y, Sutedjo, Sato T, Sukartiningsih. 2017. Sixteen years changes in tree density and aboveground biomass of a logged and burned dipterocarp forest in East Kalimantan, Indonesia. Biodiversitas 18: 1159-1167. Changes in tree density and aboveground biomass (AGB) of a logged and burned lowland dipterocarp forest were monitored in Bukit Soeharto Research and Education Forest (BSREF) of Mulawarman University, East Kalimantan, Indonesia. A 9-ha plot was established in 1997 to investigate the effect of second felling and the subsequent recovery. Experimental felling was conducted in October 1997, and the plot was burned by uncontrolled fires between February and April 1998. Stem diameter of living trees (diameter at breast height ≥ 10 cm) in the plot was recorded annually. Allometric functions and the annual tree inventory were used to estimate changes in AGB. Tree density in the 9-ha plot was 429 trees ha−1 before the experimental felling.This decreased to 76 trees ha−1 in 2000 because of the felling and fires. Tree density increased to 515 trees ha−1 until 2008 and then decreased to 408 trees ha−1 in 2014. AGB of the 9-ha plot was 279 Mg ha−1 in 1997,which decreased to 96 Mg ha−1 in 2000 and then increased to 139 Mg ha−1 in 2014. After 16 years of the 1998 fires, in 2014, BSREF consists of a mosaic of forest stands that are dominated by either large late successional tree species or small pioneer trees. The former stands consisted of numerous late successional tree species that survived the felling and fires. The latter stands were dominated by a few pioneer species. In 2016, 16 years after the fire, these pioneer dominating stands are now undergoing a transitional stage from pioneer to late successional trees that grow longer and larger than the pioneer trees. Logged and burned forest stands may recover their AGB comparable to that of the original forest (≥400 Mg ha−1), if these stands are saved from further logging and fires in the longterm.

Of the 42 countries that have participated in ICP Forests since 1986, 27 countries reported largescale monitoring data from Level I plots and more detailed forest ecosystem related monitoring data from Level II plots for the year 2012. In total, the participating countries provided information on more than 15,000 plots and more than 220,000 trees. Data analyses for this 2013 Technical Report focused on the impact of air pollution on tree crown condition and on sulphate and nitrogen deposition to forests. In addition, the impact on individual trees of factors other than air pollution, e.g., biotic agents, was assessed. Crown condition is the most widely applied indicator for forest health and vitality of European forests. One of its primary parameters is the rate of defoliation, which is assessed as the percentage of needle/leaf loss in the crown compared to a reference tree with full foliage. The mean defoliation of 114,361 sample trees on 6,168 transnational Level I plots in 2012 was 19.7%. Of all trees assessed in 2012 every fourth to fifth tree (22.9%) was scored as damaged, i.e., had a defoliation rate of more than 25%. In general, broadleaved trees showed a higher mean defoliation rate than conifer species (23.6% and 20.2%, respectively). Oak species still seem to be the most vulnerable of all the investigated species. Of the main species groups, deciduous temperate oak species had the highest mean defoliation (26.5%), closely followed by Mediterranean evergreen oak species (25.2%), and deciduous (sub-) temperate oak species (24.6%). A mean defoliation rate of 19.6% was assessed for European beech (Fagus sylvatica). Coniferous species expressed lower defoliation rates on average, with European spruce (Picea abies) reaching 19.2%, followed by Scots pine (Pinus sylvestris) with 19.3%, and Mediterranean lowland pine species with 20.7%. These figures are, however, not directly comparable to those of previous reports because of fluctuations in the plot sample that are primarily due to changes in the annual participation of countries. Therefore, the temporal development of crown condition was calculated separately from the monitoring results for those countries which have submitted data every year without interruption since 1993, 1998, and 2002, respectively. In addition, maps were drawn that depict temporal species trends in defoliation. The presented results suggest that there was no overall improvement of crown condition for the longest analyzed time period from 1993 to 2012. Over the last 20 years the percentage of plots with clearly increasing mean defoliation (17.2%) even exceeded the share of plots with decreasing defoliation (12.5%) but most of the investigated plots showed no statistically significant change in crown condition (70.3%). Compared to the previous year only, the investigated trees showed on average similar rates of defoliation in 2012. More than three out of four plots (78.7%) showed no statistically significant difference in mean defoliation between those two years. Defoliation increased on 13.8% and decreased on only 7.5% of the plots.

Factors driving tree mortality in retained forest fragments