https://treesearch.fs.fed.us/pubs/Top 20 NRS Pubsen-usWed, 18 Jan 2017 21:52:47 +0000https://treesearch.fs.fed.us/pubs/53400This resource update provides an overview of forest resources in Minnesota based on an inventory conducted by the U.S. Forest Service Forest Inventory and Analysis (FIA) program at the Northern Research Station in cooperation with the Minnesota Department of Natural Resources. Estimates are based on field data collected during measurement years 20112015 with comparisons made to field data collected in 20062010. The 20112015 sample data consist of 6241 field measured plots on forest land with 20 percent collected per year. Data used in this publication were accessed from the FIA database in March 2016 based on methods described in Bechtold and Patterson (2005) and OConnell et al. (2014).Wed, 11 Jan 2017 14:27:39 +0000https://treesearch.fs.fed.us/pubs/53411This resource update provides an overview of forest resources in North Dakota based on an inventory conducted by the USDA Forest Service Forest Inventory and Analysis (FIA) program within the Northern Research Station in cooperation with the North Dakota Forest Service. Estimates are based on field data collected using the FIA annualized sample design and are updated yearly. Information about the national and regional FIA program is available at httpfia.fs.fed.us. For the 2016 inventory estimates for variables such as area volume and biomass are based on 7595 plot samples collected from 20112016. Change variables such as net growth removals and mortality are based on 7588 samples collected in 20062011 and 20112016. Estimates from earlier annual and periodic inventories are shown for comparison. See Bechtoldand Patterson (2005) and OConnell et al. (2016) for definitions and technical details.Fri, 13 Jan 2017 10:20:42 +0000https://treesearch.fs.fed.us/pubs/53355Uncertainty about future outcomes of invasions is a major hurdle in the planning of invasive species management programs. We present a scenario optimization model that incorporates uncertainty about the spread of an invasive species and allocates survey and eradication measures to minimize the number of infested or potentially infested host plants on the landscape. We demonstrate the approach by allocating surveys outside the quarantine area established following the discovery of the Asian longhorned beetle (ALB) in the Greater Toronto Area (GTA) Ontario Canada. We use historical data on ALB spread to generate a set of invasion scenarios that characterizes the uncertainty of the pests extent in the GTA. We then use these scenarios to find allocations of surveys and tree removals aimed at managing the spread of the pest in the GTA. It is optimal to spend approximately one fifth of the budget on surveys and the rest on tree removal. Optimal solutions do not always select sites with the greatest propagule pressure but in some cases focus on sites with moderate likelihoods of ALB arrival and low host densities. Our approach is generalizable and helps support decisions regarding control of invasive species when knowledge about a species spread is uncertain.Wed, 04 Jan 2017 09:36:51 +0000https://treesearch.fs.fed.us/pubs/53419The likely spread of the current spruce budworm (SBW Choristoneura fumiferana Clem.) outbreak fromhigh to low density areas brings to the forefront a pressing need to understand its dispersal dynamics and to document mass exodus flights in relation to weather patterns. In this study we used the weather surveillance radar of Val dIrne in eastern Canada in combination with weather information from the Rapid Update Cycle (RUC) model output to track and document a SBW mass exodus flight that occurredon July 1516th 2013. Analyses confirmed the potential of using weather radar and RUC data to help assess SBW mass exodus dynamics. Weather surveillance radar data suggested that the mass exodus flight originated from both the northern and southern sides of the St Lawrence River estuary with mostindividuals originating from severely defoliated areas on the north shore. During the exodus flight SBW moths may have covered a distance of over 200 km. Detailed largescale assessment of this mass exodus flight using radar data allowed for the identification of convergence zones and a liftoff from a lightly defoliated area which has never been documented before. Based on radar and lower tropospheric weather data SBW dispersed downwind in a rather shallow layer probably between 400 and 800 m. These results imply that moths were generally dispersing in the vicinity of the top of the temperature inversion zone where both temperature and wind were highest throughout the exodus flight period. We advocate that the use of weather radar technology coupled with data on lower tropospheric weather conditions might benefit other monitoring tools already being used and may also help calibrate SBW atmospheric transport models.Wed, 18 Jan 2017 09:18:36 +0000https://treesearch.fs.fed.us/pubs/53414A demographic approach based on a sizestructured version of the McKendrickVon Foerster equation is used to demonstrate a theoretical link between the population size distribution and the underlying vital rates (recruitment mortality and diameter growth) for the population of individuals whose diameter distribution is negative exponential. This model supports the conclusion that the negative exponential distribution as applied to balanced natural unevenaged stands is a stable equilibrium model under appropriate assumptions. These assumptions include constant recruitment of stems into the smallest class that balances total mortality and a simple relation between per capita mortality and diameter growth. A simple maximum likelihoodbased solution to parameter estimation in the inverse problem is developed allowing the estimation of recruitment and mortality given reasonable sample of diameters along with an estimate of population size and diameter growth rate. Two sets of stand dynamics equations are developed that are based on (i) the form of the underlying negative exponential distribution and (ii) more generally from the derivation of the McKendrickVon Foerster equation. Applications of the methods and their assumptions are discussed with regard to both managed and old growth unevenaged stands. Stands or forests that are close to negative exponential structure and are judged to be reasonably close to steady state will have vital rates that support this model. In contrast the negative exponential is likely more important and applicable as a pragmatic target distribution when used in managed forests.Tue, 17 Jan 2017 10:18:32 +0000https://treesearch.fs.fed.us/pubs/53402Efforts to manage and eradicate invasive species can benefit from an improved understanding of the physiology biology and behavior of the target species and ongoing efforts to eradicate the Asian longhorned beetle (Anoplophora glabripennis Motschulsky) highlight the roles this information may play. Here we present a climatedriven phenology model for A. glabripennis that provides simulated lifetables for populations of individual beetles under variable climatic conditions that takes into account the variable number of instars beetles may undergo as larvae. Phenology parameters in the model are based on a synthesis of published data and studies of A. glabripennis and the model output was evaluated using a laboratoryreared population maintained under varying temperatures mimicking those typical of Central Park in New York City. The model was stable under variations in population size simulation length and the Julian dates used to initiate individual beetles within the population. Comparison of model results with previously published fieldbased phenology studies in native and invasive populations indicates both this new phenology model and the previously published heatingdegreeday model show good agreement in the prediction of the beginning of the flight season for adults. However the phenology model described here avoids underpredicting the cumulative emergence of adults through the season in addition to providing tables of life stages and estimations of voltinism for local populations. This information can play a key role in evaluating risk by predicting the potential for population growth and may facilitate the optimization of management and eradication efforts.Thu, 12 Jan 2017 10:17:34 +0000https://treesearch.fs.fed.us/pubs/53418Natural forest disturbances which drive succession and development differ in extent severity and return interval and range from frequent gapscale disturbances to infrequent standreplacing events. Most studies have focused on natural disturbances near the ends of the disturbance severity gradient and relatively little quantitative information is available on intermediateseverity disturbance. On 20 April 2011 an EF1 tornado tracked 5 km through the Sipsey Wilderness in Alabama and resulted in a patchwork mosaic of disturbed areas. To analyze the effects of the intermediateseverity wind event on composition structure and intrastand spatial patterns we established a 100 200 m (2 ha) rectangular plot perpendicular to the path of the storm within an affected Quercus alba stand. Based on the basal area removed (i.e. basal area of snags snapped stems or uprooted stems in decay class 1) by the wind event we divided the plot into disturbance classes (minimal light and moderate) to compare compositional and structural attributes along a disturbance severity gradient. Composition varied little across the disturbance gradient but diversity was highest in the moderately disturbed neighborhoods. Stems were relatively intermingled by species (i.e. each tree neighbored by trees of different species) in each disturbance severity class. However some species such as Fagus grandifolia and Ostrya virginiana exhibited less intermingling than Quercus spp. and stems classed in the other spp. taxonomic group. Large stems were disproportionately removed by the storm in the light and moderate disturbance categories. In the light disturbance class O. virginiana was significantly less likely to experience mortality from the storm which may in part explain the relatively high density of O. virginiana stems in the plot.Wed, 18 Jan 2017 08:21:36 +0000https://treesearch.fs.fed.us/pubs/53416The spread of white nose syndrome raises serious concerns about the longterm viability of affected bat species. Here we examine the geographic distribution of genetic variation levels of population connectivity that may influence the spatial spread of WNS and the likelihood that recent population declines in regions affected by WNS have led to the loss of unique genetic variation for the endangered Indiana bat (Myotis sodalis). We amplified a fragment of the mitochondrial control region for 375 individuals and genotyped 445 individuals at 10 microsatellite loci from 18 sampling sites distributed across the majority of the species range. Analysis of mitochondrial DNA indicated the presence of at least five distinct matrilineal clusters with the most pronounced differences between northeastern sites and those in the rest of the range. The majority of individuals in the Ozark Central Midwest and Appalachian recovery units fell into a single cluster. Significant differentiation also was observed between one Appalachian and one Midwestern site and the majority of other sites. However using nuclear microsatellites we observed the absence of differentiation and widespread gene flow among all hibernacula suggesting the occurrence of extensive gene flow through dispersal and mating. The absence of genetically distinct populations within the range of Indiana bats indicates a lack of barriers to WNS transmission and it is unlikely that significant portions of the hibernating population of Indiana bats will remain disease free into the future. Further while matrilineal gene flow was restricted among some sites and regions we found no genetic evidence to support the division of Indiana bats into separate recovery units.Wed, 18 Jan 2017 07:07:07 +0000https://treesearch.fs.fed.us/pubs/53417Fieldbased public natural resource managers in the Lake States (MI MN WI) were surveyed for theirperspectives on various aspects of private forest land parcelization. This includes their perceptions ofrecent changes in parcelization activity drivers and impacts mitigation strategies and ability to influenceparcelization. Their perspectives on the implications private forest land parcelization has on public landmanagement were also sought. Across the Lake States most public natural resource managers havewitnessed an increasing frequency of forest land parcelization. They consider development potential andproximity to population centers to be the most influential driver of parcelization with decreased timbersupply and loss of recreational access on private land the most likely outcomes. The study documentedimportant perceived linkages between private forest land parcelization and public land managementsuch as increased conflicts on public land decreased access to public land and increased demand for andcost of managing public land.Wed, 18 Jan 2017 07:17:39 +0000https://treesearch.fs.fed.us/pubs/53381The emerald ash borer Agrilus planipennis Fairmaire (Coleoptera Buprestidae) is an important invasive pest of ash (Fraxinus) trees in North America. Two larval parasitoid species Tetrastichus planipennisi Yang (Hymenoptera Eulophidae) and Spathius agrili Yang (Hymenoptera Braconidae) and 1 egg parasitoid species Oobius agrili Zhang and Huang (Hymenoptera Encyrtidae) were introduced into the United States in 2007 as part of a classical biological control program. We conducted field studies to assess the flight phenology of introduced and native parasitoids of emerald ash borer in central Michigan from 2011 to 2013 by using sentinel logs. Parasitism rates of sentinel A. planipennis eggs by O. agrili fluctuated throughout the season from 0 to 22 in 2011 and 0 to 6 in 2012. Flight phenology of O. agrili adults varied between years and discrete generations were not apparent. Rather O. agrili adults were generally continually present over a 3 mo period each year. Parasitism rates of sentinel A. planipennis larvae by T. planipennisi and the North American native Atanycolus spp. (Hymenoptera Braconidae) respectively ranged from 0 to 5 and 33 to 77 in 2011 from 0 to 69 and 0 to 27 in 2012 and from 0 to 53 and 0 to 46 in 2013. Phenology of adult flight of both T. planipennisi and Atanycolus spp. was inconsistent between years. Development of nondestructive methods to determine when stages of A. planipennis suitable for parasitism are present in combination with the use of sentinel logs to observe parasitoid phenology as described here will enhance the ability to evaluate the impacts of parasitoids on emerald ash borer.Tue, 10 Jan 2017 14:33:48 +0000https://treesearch.fs.fed.us/pubs/53357The walnut twig beetle WTB (Pityophthorus juglandis Blackman) is the primary insect vector for a pathogen that causes thousand cankers disease (TCD) a disease complex that leads to mortality in species of walnut (Juglans L.). We performed field and laboratory trials to determine if reproduction by WTB varies between two black walnut (Juglans nigra L.) parent trees of a fullsib mapping population of 323 offspring and between black walnut and butternut (Juglans cinerea L.). These two tree species are native to eastern North America. In field trials we found no significant differences in colonization density or mean number of adult offspring per female among branch sections from black walnut parent trees or among branch sections from black walnut and butternut respectively. In laboratory trials with controlled colonization densities of WTB we found that significantly fewer adult offspring developed in branch sections of the black walnut maternal Sparrow parent than the paternal Schessler parent over three summer months and one winter month. In the field high colonization densities likely limited reproduction due to increased intraspecific competition beneath the bark. In the laboratory where we established a lower colonization density reproduction was likely influenced by differences in host quality. In laboratory trials no differences were detected in the number of adult offspring emerging from black walnut and butternut accessions. This finding suggests that butternut is a suitable host for WTB. Future screening of the fullsib mapping population of 323 offspring of black walnut parent trees for WTB resistance is a warranted next step in developing alternative management strategies for TCD in black walnut.Wed, 04 Jan 2017 09:47:41 +0000https://treesearch.fs.fed.us/pubs/53408Anoplophora glabripennis has a complex suite of matefinding behaviors the functions of which are not entirely understood. These behaviors are elicited by a number of factors including visual and chemical cues. Chemical cues include a maleproduced volatile semiochemical acting as a longrange sex pheromone a femaleproduced cuticular hydrocarbon blend serving as a sexidentification contact pheromone and a recently identified femaleproduced trail sex pheromone that is followed by mateseeking males. However the sensory appendages and sensilla on these appendages used to detect the trail sex pheromone are unknown. We evaluated the ability of virgin male A. glabripennis to follow a sex pheromone trail after removal of the terminal four antennal segments andor the maxillary and labial palps using a twochoice behavioral bioassay. We also tested the ability of males to follow the trail sex pheromone using volatile pheromone cues only without physical contact with the pheromone. Results indicate that the palps are primarily responsible for sensing the pheromone with males lacking palps unable to respond behaviorally to the trail sex pheromone. Under the conditions of this study males could not follow the sex pheromone trail without direct contact suggesting that olfaction may not be involved in detection of this pheromone. However we did not determine to what degree the trail pheromone chemicals can volatilize under our experimental conditions. This work is important in elucidating the behaviors and sensory structures involved in matefinding by this species on host trees and these studies may help determine whether the trail sex pheromone has applications for monitoring and management.Fri, 13 Jan 2017 08:53:57 +0000https://treesearch.fs.fed.us/pubs/53415The uneven provisioning of ecosystem services has important policy implications yet the spatial heterogeneity of tree canopy remains understudied. Private residential lands are important to the future of Philadelphias urban forest because a majority of the existing and possible tree canopy is located on residential land uses. This article examines the spatial distribution of tree canopy in Philadelphia PA and its social correlates. How are existing tree canopy and opportunities for additional tree canopy distributed across the city of Philadelphia and with respect to three explanations (i) population density (ii) the social stratification luxury effect and 3) lifestyle characteristics of residents? This study used spatial autoregressive regression (SAR) geographically weighted regression (GWR) and multilevel modeling (MLM) to evaluate population density social stratification luxury effect and lifestyle characteristics as explanations of the spatial distribution of existing and possible tree canopy and simultaneously evaluate the efficacy of different statistical analysis techniques. To control for spatial autocorrelation SAR models were estimated GWR models were fit to examine potential spatial nonstationarity and realism of the SAR analyses. The MLMs both controlled for spatial autocorrelation (like SAR) but also allow local variation and spatial nonstationarity (like GWR). The multimodel inferential approach showed the statistical models that included lifestyle characteristics outperformed the social stratification and population density models. Our results cast doubt on findings from previous studies using areal units such as block groups. More sophisticated statistical analyses suggest opportunities for enhancing theory and the need to reconsider frequently used methods.Tue, 17 Jan 2017 10:25:15 +0000https://treesearch.fs.fed.us/pubs/53409The fringes of cities and rural properties within commuting distance of cities experience some of the est rates of development in the world. This can cause dramatic changes to the landscape the alteration logical functions and a reduction in biodiversity. With the spread of suburbia however come opportunities for some species to exploit new resources. While many wild creatures can enrich the lives of suburban dwellers large increases in the populations of species such as deer beaver and coyotes can lead to a change in status from resource to pest. For several decades wildlife managers have alternately embraced and issues related to urban and suburban wildlife. Today management of suburban areas challenges wildlife agencies on two fronts the threat to habitat and biodiversity and the problem of overabundant wildlife. This is not only a tremendous management challenge but also an educational opportunity to help people understand the natural world and their place in it.Fri, 13 Jan 2017 09:01:14 +0000https://treesearch.fs.fed.us/pubs/53407By synthesizing more than twenty years of research at the Fernow Experimental Forest we have documented 7 symptoms of nitrogen saturation in two adjacent watersheds. The symptoms include 1) high relative rates of net nitrification 2) longterm increases in streamwater concentrations of nitrate and base cations 3) relatively high nitrate concentrations in solution losses 4) little seasonal variability in streamwater nitrate concentrations 5) a high discharge of nitrate from a young aggrading forest 6) a rapid increase in nitrate loss following fertilization of a young aggrading forest and 7) low retention of inorganic nitrogen when compared with other forested sites. These data support current conceptual models of nitrogen saturation and provide a strong and perhaps the best example of nitrogen saturation in the United States.Fri, 13 Jan 2017 08:47:51 +0000https://treesearch.fs.fed.us/pubs/53346Although extensive research on acidic deposition has been directed toward sprucefir forests less research has been done on the impacts of air pollution on eastern montane hardwood forests. The purpose of this study was to describe precipitation chemistry for several Appalachian hardwood forest sites at or near the Fernow Experimental Forest (FEF) to assess the potential for problems associated with acidic deposition. Emphasis was placed on seasonal patterns of ionic concentrations (H Ca NH4 NO3 and S04) and spatial variability of ionic concentrations and deposition among sites. Seasonal patterns of most ions showed highest concentrations during the summer months and deposition of H was especially pronounced during this time. Deposition of all ions was generally greater (related to greater precipitation) at three montane forested sample sites compared to a nonforested riverbottom site. Precipitation chemistry at FEF was similar to other sites throughout the eastern United States and contrasted sharply with midwestern and western sites. Eastern sites including means for FEF sites were unifonnly 34 times higher in H and S04 concentration than the midwestern and western sites. Precipitation at FEF was chronically acidic more so during the growing season and highest at higher elevations where environmental stresses can be most severe. Furthermore there were occasional large discrepancies between the lowelevation site and the higherelevation forested sites for precipitation chemistry and acidic deposition. These results suggest that synopticscale (network) data may greatly underestimate the pollutant conditions to which highelevation forest trees are exposed since network data rarely take elevation into account and typically are based on annual ionic concentration and deposition means that may be considerably lower than those of the growing season.Wed, 28 Dec 2016 12:49:49 +0000https://treesearch.fs.fed.us/pubs/53345The current interest among resource managers in ecosystem management necessitates a better understanding of the response of plant species diversity to forest management practices. This study attempted to assess the effects of one forest management practiceclearcuttingon plant biodiversity in a midAppalachian hardwood forest by comparing species composition and diversity between two young (20 yr following clearcutting) and two mature (gt70 yr following selective cutting) watersheds. Sampling was confined to the herbaceous layer (vascular plants1m in height) and woody overstory (stems 2.5 cm diameter at 1.5m height). The important tree species occurred on all watersheds but the relative importance of these species varied greatly with stand age. Less shadetolerant species such as black cherry (Prunus serotina) and tulip poplar (Liriodendron tulipifera) are replaced by moretolerant species such as northern red oak (Quercus rubra) and sugar maple (Acer saccharum) as the stand matures. Analysis of tree species richness per plot suggests that the competitive thinning process decreases species evenness as the stand develops. Important herblayer species included stinging nettle (Laportea canadensis) violets (Viola spp.) seedlings of striped maple (A. pensylvanicum) and several fern species. In sharp contrast with the trees these species appeared to vary little with stand age. Species diversity (H) did not vary with stand age for either the overstory or the herbaceous layer. Detrended correspondence analysis showed a significant correlation between species composition of the two strata for the mature watersheds but not the young clearcut watersheds. Thus we suggest a temporal shift in processes influencing species composition following disturbance from allogenic factors (e.g. soil characteristics) to autogenic factors (e.g. stand characteristics) which lead to a linkage between forest strata later in succession. The degree to which forest management alters species composition in these central Appalachian forest ecosystems may be tied to the degree of alteration of the link between strata.Wed, 28 Dec 2016 12:33:43 +0000https://treesearch.fs.fed.us/pubs/53410Breeding bird communities were compared in three suburbs a 70yearold area of large houses along streets shaded by mature trees (MT) primarily oaks (Quercus) and elms (Ulmus) a 15yearold area built upon open agricultural land with young maple (Acer) street trees (YT) and a 15yearold area on which houses were built in small clearings within a secondgrowth oakpine (QuercusPinus) woodland (OP). Bird censuses each year for 5 years revealed that YT supported the lowest total avian density of the three suburbs OP supported the greatest variety and total density of insectivores and the lowest number of groundgleaning omnivores and MT supported the highest total avian density comprised primarily of groundforaging seed eaters and omnivores. Among nesting guilds OP contained the fewest groundherb nesters and MT the most. Also OP had the fewest shrub nesters and MT the most. Tree cavity and twig nesters were significantly more numerous in OP and tree branch nesters fewer in YT than in either OP or MT. Analyses of habitat structure revealed that shrub maturity is more important than numbers of shrubs and that planted trees no matter how mature or abundant do not replace natural forest stands as habitat for most insectivorous species.Fri, 13 Jan 2017 09:18:26 +0000https://treesearch.fs.fed.us/pubs/53383Trees have a spectacular survival record. Over a period of more than 400 million years they have evolved as the tallest most massive and longestlived organisms ever to inhabit the earth. Yet trees lack a means of defense that almost every animal has trees cannot move away from destructive forces. Because they cannot move all types of living and nonliving enemiesfire storms microorganisms insects other animals and later manhave wounded them throughout their history. Trees have survived because their evolution has made them into highly compartmented organisms that is they wall off injured and infected wood.Tue, 10 Jan 2017 14:48:15 +0000https://treesearch.fs.fed.us/pubs/53382The purpose of this chapter is to describe a conceptual framework for understanding how trees grow and how they and other perennial plants defend themselves. The concept of compartmentalization has developed over many years a synthesis of ideas from a number of investigators. It is derived from detailed studies of the gross morphology and cellular anatomy of the wood and bark of roots and stems in healthy angiosperms and gymnosperms. It is based on research in tree physiology and the chemistry of wood and bark. It is founded on observations of trees injured in the field by wind snow ice fire animals and insects as well as during pruning coppicing sugaring and other forest and orchard management practices. It is based on experimental studies of natural and artificial wounds with and without controlled inoculations with selected pathogenic and saprophytic microorganisms. These microbes have included wooddecaying Basidiomycetes and Ascomycetes woodstaining Ascomycetes and Fungi Imperfecti canker fungi and a myriad of woodinhabiting bacteria. The end result of all these studies is an integrating concept that involves defenses laid down by trees prior to injury and defenses laid down by trees after injury.Tue, 10 Jan 2017 14:43:45 +0000