Top 20 NRS Pubshttps://treesearch.fs.fed.us/pubs/Top 20 NRS Pubsen-usWed, 17 Jul 2019 15:11:04 +0000An assessment of Canada thistle in northern U.S. forestshttps://treesearch.fs.fed.us/pubs/58158This publication is part of a series that provides an overview of the presence of invasive plant species monitored on an extensive systematic network of plots measured by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service Northern Research Station (NRS). Each research note features one of the invasive plants monitored on forested plots by NRS FIA in the 24 states of the Midwestern and Northeastern United States. Canada thistle (Cirsium arvense) is an herbaceous perennial in the Aster family. Since its arrival to North America from Europe in the early 1600s via contaminated crop seed it has caused considerable impact by displacing native plants and reducing crop and pasture productivity (Czarapata 2005 Kaufman and Kaufman 2007).Tue, 18 Jun 2019 07:05:52 +0000Assessing preferences for growth on the ruralurban fringe using a stated choice analysishttps://treesearch.fs.fed.us/pubs/58118Increasing the capacity of communities on the ruralurban fringe to accommodate sustainable growth is a key concern among resource management agencies. Decisions about the future of these landscapes involve difficult tradeoffs that underscore the importance of incorporating diverse stakeholder values and preferences into planning efforts. We assessed residents preferences for exurban growth alternatives in two Midwestern U.S. countiesnbsp Jasper County IA and Will County ILnbsp that have strong agrarian roots and lie at the fringe of rapidlyexpanding metropolitan areas. Using a choice model we identified how six landscape characteristics influenced respondents stated choices for growth scenarios. Informed by previous research focus groups and pilot testing our final model evaluated preferences for residential growth protected grasslands recreation agriculture bison reintroduction and unemployment. Results from a countywide survey mailed to 3000 residents (final N889) indicated that five of the six landscapescale attributes significantly influenced residents choices. Increased residential growth more protected grasslands and agricultural lands and greater access to recreation positively predicted choices for hypothetical growth scenarios while residents preferred future scenarios with low levels of unemployment. Further the strength of preferences for these land use and economic conditions differed between Jasper and Will County residents. The study findings aid decision makers who face growth and urbanization pressures and provide insight on how to integrate preferences of current residents into planning decisions at a regional scale.Tue, 11 Jun 2019 14:04:41 +0000Can group selection with legacy retention change compositional trajectories in conventionally managed hardwoods?https://treesearch.fs.fed.us/pubs/58197Group selection has been proposed as a complementary system to conventional unevenaged management in temperate hardwoods (i.e. singletree selection) to counteract declines in overstory diversity and growing importance of shadetolerant species caused largely by past management activities. Mixed results from experimental group selection harvests in eastern North America and growing interest in retention forestry have led some scientists and managers to apply ideas from retention forestry into group selection systems. The Yellow Birch LegacyTree Project is a group selection experiment established in 2003 which incorporates single dominantcodominant yellow birch (Betula alleghaniensis Britt.) legacytrees into the centers of harvested canopy gaps in a northern hardwoods forest in the Upper Peninsula of Michigan. Group selection openings (n49) in three size classes based upon radiismall (11 m n16) medium (16.5 m n17) and large (22 m n16)were surveyed alongside singletree selection reference sites (n20) 15 years postharvest. Our goals were to (1) examine longterm trends in seedling and sapling abundance and diversity (2) evaluate the initial and contemporary effects of gap size on regeneration and (3) assess the overall efficacy of groupselection with legacytree retention in regenerating midtolerant and intolerant species especially yellow birch. At 15 years postharvest we found that shadetolerant sugar maple (Acer saccharum Marsh.) dominated regeneration layers across all treatments but we observed modest increases in seedling and sapling diversity within openings that may alter longterm canopy composition over several cutting cycles. We found that gains in diversity and evenness in canopy gaps persisted through time and that large gaps (22m radius) had the most speciesrich and diverse regeneration compared to reference sites. Canopy gaps contained significantly higher densities of shadeintolerant and midtolerant seedlings and saplings compared to reference sites namely red maple (Acer rubrum L.) black cherry (Prunus serotina Ehrh.) and yellow birch however most diversity occurred in shorter height classes. Nevertheless legacy retention within group selection systems holds promise for maintaining ecological memory and structural complexity through time but further treatments such as scarification may be necessary to shift compositional trajectories in favor of shadeintolerant and midtolerant species.Mon, 01 Jul 2019 11:59:55 +0000Changes in the quality of the northern U.S. hardwood timber resource from 2008 to 2017https://treesearch.fs.fed.us/pubs/58224High quality North American hardwood lumber and veneer is increasingly exported and used worldwide. A large portion of the timber resource utilized in the production of these products is contained within the northern region of the eastern United States. The cubic volume of this resource has increased by 15 since 2000 with most of this increase occurring in trees greater than 43.2 cm diameter at breast height. Although the volume of highquality timber is likely at its highest level in over 100 years 60 of the increase in the volume between 2008 and 2017 was in sawtimbersize (27.9 cm and larger) trees of low quality. Region wide the species group other white oaks had the largest increase in highquality volume. The largest increases in lowquality volume were for the soft maple and other red oaks species groups. While the volume of poletimber (12.7 to 27.7 cm) growing stock decreased between 2008 and 2017 the volume of cull poletimbersize trees increased more than 50. These trends indicate a future decline in timber quality. Research is needed to determine the cause of these declines and how they may be reversed. One question that should be examined is the role of natural mortality and damage versus human disturbance on timber quality.Mon, 08 Jul 2019 14:07:31 +0000Deer browsing overwhelms extended leaf phenology benefits A test case with Rubus allegheniensis and a recalcitrant hayscented fern layerhttps://treesearch.fs.fed.us/pubs/58161Plant species coexistence can be promoted by multiple tradeoffs including temporal niche separation via differences in phenology. Namely if phenological differences afford longer leaf lifespans that confer species the opportunity to exploit light and fix carbon during periods relatively free of other competitors then coexistence or even competitive superiority may arise. Phenological niche separation explanations including the Extended Leaf Phenology (ELP) hypothesis have garnered considerable support as a mechanistic explanation for both exotic invasive species success and maintenance of native plant species. The benefits conferred by a phenological advantage however can be nullified if tissue losses from browsing are coincident with this phenological window of opportunity. This study experimentally tests the role of phenological advantage and whitetailed deer (Odocoileus virginianus) browsing alone and in concert in structuring coexistence between the native forest shrub Rubus allegheniensis which possesses an extended phenological window and the native invasive fern Dennstaedtia punctilobula. Browsing treatments (ambient versus excluded) were factorially crossed with shading treatments (none versus shading timed to eliminate phenological advantage). The results demonstrate the phenological advantage is an essential growth mechanism for Rubus as seedlings deprived of the ELP advantage were on average 50 shorter than those not treated with shade. However this benefit was largely dependent on herbivory pressure as deer browsing largely nullified the growth benefits provided by the phenological advantage. This experiment is the first experimental study documenting how browsing impacts affect a plant species by curtailing a phenological coexistence advantage. The results suggest elucidating the interacting roles of the ELP and browsing is critical particularly as the phenological niche advantage does not necessarily constitute a fitness advantage where browsing pressure is high. Results from this work also provide broader insight into how exotic plant species invasions that are assumed to be aided by a phenological (ELP) advantage may be modulated through their browse susceptibility. Overall these results suggest understanding the cooccurring roles of phenology and browsing may guide management decisions to maintain or promote understory plant diversity.Wed, 19 Jun 2019 13:01:35 +0000Drivers of individual tree growth and mortality in an unevenaged mixedspecies conifer foresthttps://treesearch.fs.fed.us/pubs/58249Individual tree growth and mortality drive forest stand dynamics and are universally important metrics of tree success. Studying factors that affect growth and mortality is particularly challenging in mixedspecies unevenaged systems due to their defining heterogeneity and strong temporal and spatial variability. The goal of this study was to determine the relative importance of individual tree attributes (i.e. species size neighborhood crowding crown position) and environmental characteristics (i.e. soil moisture) in driving tree growth and survival in an unevenaged mixed species forest. In particular we tested if the factors regulating growth were the same as those regulating mortality as is often assumed. Due to its large size and intensive sampling the 3ha stemmapped plot (established in 1989) at Howland Research Forest in central Maine USA allowed us to address additional questions regarding the influence of sapling crowding neighbor species identity and legacies of past disturbance. Growth and survival of over 3000 plot trees was assessed after 25 years and modeled using multiple linear regression (growth) and binary logistic regression (survival). As expected species neighborhood crowding and tree diameter were top predictors of growth and survival. Specifically growth and survival decreased with greater crowding and increased with larger diameters. We also found that the identity of neighbors influenced focal tree growth growth generally improved in neighborhoods comprised of species different from that of the focal. However this general finding did not hold for all species eastern hemlock grew better in hemlock neighborhoods and northern whitecedar showed no response related to neighbor identities. In contrast to growth neighborhood identity was not related to survival. Crowding from saplings did not explain any additional variability in growth however unexpectedly individuals with greater sapling crowding were more likely to survive. For both growth and survival we found an interaction between crowding and soil moisture suggesting that within a single stand individual success can be limited by both excess and insufficient moisture. We found no relationship between neighborhood cut stumps (legacy of past disturbance) and recent growth or survival. These results highlight the many variables driving growth and survival in unevenaged mixedspecies forests. The top predictors for growth were identical to those for survival however other predictors differed in their relative importance. Given the recent emphasis on promoting unevenaged mixedspecies forests we suggest that studies addressing a full range of predictors of individual tree success are necessary to better manage and maintain these complex systems.Tue, 16 Jul 2019 07:07:16 +0000Effect of Prescribed Fire on Timber Volume and Grade in the Hoosier National Foresthttps://treesearch.fs.fed.us/pubs/58167Lowintensity surface fire is prescribed in eastern North American hardwood stands prior to overstory harvest in order to improve regeneration and recruitment of oak and other firetolerant and fireadapted species. However this use of prescribed fire potentially can reduce timber value. We inventoried overstory trees (gt10 in. diameter at breast height) in 54 oakdominated stands with varied prescribed fire histories and aspects in southern Indiana. We then documented the extent of prescribed fire damage (i.e. wounds) to overstory trees and quantified both the relative stand volume of timber loss and the proportion of trees that had tree grade reductions because of prescribed fire. Generally as a stand received more prescribed fires more trees were scarred the relative volume lost increased and a higher proportion of trees declined in grade. Overall burned stands experienced less than 10 percent sawtimber volume loss regardless of the number of prescribed fires and aspect. Less than 3 percent of trees studywide had reduced grade because of prescribed fire. Grade and volume reductions varied by species however. Our results suggest that prescribed fire has a minor economic impact on standing timber particularly when timber is harvested within two decades of the first fire.Thu, 20 Jun 2019 12:46:01 +0000Futures Research Methods and Applications in Natural Resourceshttps://treesearch.fs.fed.us/pubs/58242Futures research is a transdisciplinary field of inquiry that uses a variety of methods to explore possible plausible and preferable futures. The goal is to develop foresightinsight into how and why the future could be different than todayto improve policy planning and decision making. Scores of futures research methods have been developed or adapted from other disciplines beginning with pioneering work in the US military and RAND Corporation in the 1950s and 1960s. But many social scientists and natural resource professionals are unaware of these methods and most have never heard of futures research as a distinct field of study. This paper presents a framework for categorizing futures research methods reviews selected methods and provides examples of their application to natural resource and environmental issues.Fri, 12 Jul 2019 12:50:38 +0000Impacts of experimental alteration of water table regime and vascular plant community composition on peat mercury profiles and methylmercury productionhttps://treesearch.fs.fed.us/pubs/58088Climate change is expected to alter the hydrology and vascular plant communities in peatland ecosystems. These changes may have as yet unexplored impacts on peat mercury (Hg) concentrations and net methylmercury (MeHg) production. In this study peat was collected from PEATcosm an outdoor controlled mesocosm experiment where peatland water table regimes and vascular plant functional groups were manipulated over several years to simulate potential climate change effects. Potential Hg(II) methylation and MeHg demethylation rate constants were assessed using enriched stable isotope incubations at the end of the study in 2015 and ambient peat total Hg (THg) and MeHg concentration depth profiles were tracked annually from 2011 to 2014. Peat THg and MeHg concentrations and the proportion of THg methylated (MeHg) increased significantly within the zone of water table fluctuation when water tables were lowered but potential Hg(II) methylation rate constants were similar regardless of water table treatment.When sedges dominate over ericaceous shrubsMeHg concentrations and MeHg became significantly elevated within the sedge rooting zone. Increased desorption of Hg(II) andMeHg fromthe solid phase peat into porewater occurredwith a loweredwater table and predominant sedge cover likely due to greater aerobic peat decomposition. Deeper more variable water tables and a transition to sedgedominated communities coincided with increased MeHg accumulation within the zone of water table fluctuation. Sustained high water tables promoted the net downward migration of Hg(II) and MeHg. The simultaneous decrease in Hg(II) and MeHg concentrations in the nearsurface peat and accumulation deeper in the peat profile combined with the trends in Hg(II) and MeHg partitioning to mobile pore waters suggest that changes to peatland hydrology and vascular plant functional groups redistribute peat Hg(II) andMeHg via vertical hydrochemical transport mechanisms.Wed, 05 Jun 2019 08:20:27 +0000Mapping black ash dominated stands using geospatial and forest inventory data in northern Minnesota USAhttps://treesearch.fs.fed.us/pubs/58243Emerald ash borer (EAB Agrilus planipennis Fairmaire 1888) has been a persistent disturbance for ash forests in the United States since 2002. Of particular concern is the impact that EAB will have on the ecosystem functioning of wetlands dominated by black ash (Fraxinus nigra Marsh.). In preparation forest managers need reliable and complete maps of black ash dominated stands. Traditionally forest survey data from the United States Forest Inventory and Analysis (FIA) Program have provided rigorous measures of tree species at large spatial extents but are limited when providing estimates for smaller management units (e.g. stands). Fortunately geospatial data can extend forest survey information by generating predictions of forest attributes at scales finer than those of the FIA sampling grid. In this study geospatial data were integrated with FIA data in a randomForest model to estimate and map black ash dominated stands in northern Minnesota in the United States. The model produced low error rates (overall error 14.5 area under the curve (AUC) 0.92) and was strongly informed by predictors from soil saturation and phenology. These results improve upon FIAbased spatial estimates at national extents by providing forest managers with accurate finescale maps (30 m spatial resolution) of black ash stand dominance that could ultimately support landscapelevel EAB risk and vulnerability assessments.Fri, 12 Jul 2019 12:56:08 +0000Perceptions of Nature and Access to Green Space in Four Urban Neighborhoodshttps://treesearch.fs.fed.us/pubs/58227Health benefits have been linked to spending time outdoors in nature and green space. However there is some evidence of inequities to accessing safe outdoor space particularly in lowresource communities. The primary aim of this study is to assess attitudes towards nature and use of green space in urban areas. A secondary aim is to describe perceptions of physicianinitiated nature prescriptions that target local pediatric populations. We conducted six focus group interviews with 42 residents who were guardians or caretakers of children living in lowresource neighborhoods in Philadelphia PA. We analyzed interview data using a conventional content analysis approach. Three major themes emerged (1) perceived benefits of being in nature (physical and mental health benefits) (2) barriers to time spent in nature (unsafe and undesirable conditions of local parks) and (3) desired features of outdoor green spaces (amenities that would increase park use). Additionally we describe participants reactions to the idea of a pediatriciandelivered prescription for outdoor green space exposure for a child in their care. Adherence to nature prescriptions programs may hinge on local green space resources as well as experiential and perceptual barriers and facilitators to nature and park accessibility among caregivers tasked with fulfilling a nature prescription for a child in their care.Mon, 08 Jul 2019 14:14:50 +0000Six years of ecosystematmosphere greenhouse gas fluxes measured in a subboreal foresthttps://treesearch.fs.fed.us/pubs/58250Carbon dioxide (CO2) methane (CH4) and nitrous oxide (N2O) are the greenhouse gases largely responsible for anthropogenic climate change. Natural plant and microbial metabolic processes play a major role in the global atmospheric budget of each. We have been studying ecosystematmosphere trace gas exchange at a subboreal forest in the northeastern United States for over two decades. Historically our emphasis was on turbulent fluxes of CO2 and water vapor. In 2012 we embarked on an expanded campaign to also measure CH4 and N2O. Here we present continuous towerbased measurements of the ecosystematmosphere exchange of CO2 and CH4 recorded over the period 20122018 and reported at a 30minute time step. Additionally we describe a fiveyear (20122016) dataset of chamberbased measurements of soil fluxes of CO2 CH4 and N2O (20132016 only) conducted each year from May to November. These data can be used for process studies for biogeochemical and land surface model validation and benchmarking and for regionaltoglobal upscaling and budgeting analyses.Tue, 16 Jul 2019 07:25:50 +0000Spotted lanternfly an Asian exotic is moving westward from the East Coasthttps://treesearch.fs.fed.us/pubs/58119The spotted lanternfly (SLF) Lycorma delicatula (White) (Hemiptera Fulgoridae) is native to China and Vietnam. An early report that SLF occurs in India was described by the author as doubtful (Distant 1906) nevertheless some papers have reported India within this insects native range. SLF has also spread to Japan and Korea in recent decades with the DNA in those populations matching very closely to populations in China (Kim et al. 2013). SLF was first reported in the USA in 2014 in Berks County Pennsylvania northwest of Philadelphia (Barringer et al. 2015 Dara et al. 2015). As of early 2019 additional established populations of SLF have been found in small areas of Delaware New Jersey and Virginia. In addition SLF individuals have been collected at various locations in Connecticut Maryland Massachusetts and New York but no established populations have yet been detected.Tue, 11 Jun 2019 14:12:18 +0000STEWMAP in the New York City region survey results of the Stewardship Mapping and Assessment Projecthttps://treesearch.fs.fed.us/pubs/58168The Stewardship Mapping and Assessment Project (STEWMAP) began in 2007 as a way to understand and map civic capacity to care for the environment across New York City. In 2017 we implemented a tenyear update to STEWMAP in New York Citys five boroughs and expanded it to the larger metropolitan area as a regional pilot survey. In this report we share our preliminary findings about the civic stewardship groups working to care for the local environment through conservation monitoring management transformation education and advocacy. The data presented include organizational characteristics collaboration networks and geographic turf. The results from the STEWMAP survey show that civic environmental stewardship is a vital force in the neighborhoods of New York City and the surrounding region. Combined the respondent stewardship groups represent an estimated 540000 members and staff working in every borough and county and with budgets totaling approximately 800 million. This capacity is spread across groups from different sectors including public health social services transportation education housing and faithbased organizations. They work at different geographic and professional scales but many share the goal of improving their communities. The work of civic stewardship groups impacts not only the physical environment but the social fabric of the places they live. This report highlights some key findings and also points to further research questions to consider for future publications.Thu, 20 Jun 2019 13:45:13 +0000The Northern WhiteCedar Recruitment Bottleneck Understanding the Effects of Substrate Competition and Deer Browsinghttps://treesearch.fs.fed.us/pubs/58162Research Highlights Regenerating northern whitecedar (Thuja occidentalis L.) is challenging throughout much of its range. This study attempts to relate differences in natural regeneration to standand seedbedlevel factors. Background and Objectives Lack of regeneration of northern whitecedar is often attributed to overbrowsing by whitetailed deer (Odocoileus virginianus Zimmerman) because whitecedar is a preferred winter browse species. However there are many other factors that may contribute to regeneration failure for whitecedar including its specific seedbed requirements and competition from other often fastergrowing trees and shrubs. Materials and Methods We surveyed five mature whitecedar stands in Wisconsin USA that have had little to no management in the past 50 years to find stem densities of natural whitecedar regeneration in three height classes. We also collected data at each stand on potential predictor variables including overstory attributes competitive environment seedbed and browsing by deer. We used model selection to create separate models to predict stem density of each whitecedar regeneration height class. Results None of the measures of deer browsing used in this study were found to be associated with whitecedar regeneration. Soil pH competition from other seedlings and saplings and stem density of whitecedar in the overstory were found to be potentially associated with whitecedar regeneration. Conclusions While browsing by deer is likely a factor affecting whitecedar regeneration in many areas this study highlights the challenge of quantifying deer browse effects as well as showing that other factors likely contribute to the difficulty of regenerating whitecedar.Wed, 19 Jun 2019 14:25:01 +0000Exotic forest pests in Michigan current and potential invadershttps://treesearch.fs.fed.us/pubs/58120Exotic ( alien nonnative) forest insects are moved between countries in many ways but primarily through wood packaging material (WPM e.g. pallets and crating) and live plants. Other means include international trade in logs firewood processed wood items passenger baggage mail as well as hitchhiking on such items as shipping containers ships aircraft and machinery (Meurisse et al. 2018). Historically WPM has commonly contained bark and woodinfesting insects because it was often made from recently cut trees with some bark retained which is attractive to many borers that infest dying and recently cut trees (Eyre and Haack 2017 Haack 2006). Travel times between countries is usually very short being a matter of hours (air travel) to days (ocean vessels) and thus has little impact on insect survival.Tue, 11 Jun 2019 14:19:22 +0000Why Garden? Personal and Abiding Motivations for Community Gardening in New York Cityhttps://treesearch.fs.fed.us/pubs/58248We explore the underlying motivations of NYC community gardeners in order to gain greater insight into how these valued public resources support individual and community wellbeing. Semistructured interviews were used to capture a range of enduring gardener motivations over time. We find that the underlying motivations of NYC community gardeners are both personal and collective. For many community gardens provide a space for reflection and for profound connection to the natural world. Gardening was reported to be restorative and to help to strengthen an individuals connection to a larger community or cultural heritage. Themes of joy and personal fulfillment were consistently most prevalent over time while the impulse to improve the community decreased in prevalence and food production and cultural identity connections became more common motivations possibly reflecting broader social shifts in NYC neighborhoods.Tue, 16 Jul 2019 07:01:36 +0000Physiographic factors underlie rates of biomass production during succession in Great Lakes forest landscapeshttps://treesearch.fs.fed.us/pubs/58244Biomass production in living trees is the basis of numerous forest ecosystem functions and services. However rates of and controls on biomass production vary widely across temperate forests particularly over successional timescales of decades and centuries. Biomass production in temperate forests is most often interpreted within the context of biotic or topdown controls such as species composition or disturbance. However there is need to investigate how bottomup physiographic factors such as landform attributes drainage and soil properties mediate biomass production. In order to investigate patterns controls and potentials for biomass production across spatial levels ranging from individual ecosystems to landscapes to entire regions we synthesized longterm forest inventory datasets from the United States Great Lakes region placed them in the context of a hierarchical ecological unit classification and tested the influence of physiographic factors on biomass production rates and temporal trajectories across ecological levels. Key findings include 1) At nearly all ecological levels physiographic controls (e.g. soil texture drainage class water table depth) on soil moisture status are significant predictors of variation in biomass production rates with mesic sites accumulating biomass more rapidly than xeric sites which in turn accumulate biomass more rapidly than hydric sites. 2) Aboveground live biomass can apparently continue to accumulate through 23 centuries of succession exceeding 300400 Mg ha1 on mesic sites throughout the region. 3) Stand age distributions indicate that hydric sites are harvested least often while the high production rates of mesic sites suggest they are most appropriate for frequent harvesting. 4) Median 1stquartile and 3rdquartile growth rates of individual ecosystems landscapes and ecoregional subsections and sections reveal ecological units in which forests may vary in their potential for increases or decreases in biomass production e.g. due to management interventions climate change or disturbances. Specifically some units have tightly constrained distributions suggesting little capacity for change in production rates relative to observed medians while other units have wide variation in biomass production rates indicating the potential for relatively large increases or decreases in production. Altogether the results of this analysis show that physiography exerts widespread bottomup controls on biomass production across the region of study and can be used in spatially explicit frameworks to understand ecosystem functioning and inform scientific forest management.Fri, 12 Jul 2019 13:01:19 +0000Measuring and interpreting flame height in wildland fireshttps://treesearch.fs.fed.us/pubs/58100Although advanced technologies are available for measuring and sampling fire intensity their costs limitations or complexity often preclude general use in field experiments. The lack of quality measurements exacerbates the task of relating ecological responses directly to the fires that cause them. In this paper a new technique for measuring flame height describing its distribution and relating it to fire intensity is presented. Flame pulsation in natural fuels is also examined.Fri, 07 Jun 2019 10:53:28 +0000A Procedure for Sampling Nymphs of Saratoga Spittlebug Aphrophora Saratogensis (Homoptera Cercopidae) Using Percentage of SampleUnits Infestedhttps://treesearch.fs.fed.us/pubs/58099A method is proposed for rapidly estimating the nymphal population of the Saratoga spittlebug on alternate host plants in young red pine plantations. The method is based on an assumption that the number of nymphs per sample unit is distributed within an infested plantation according to the negative binomial distribution. This method can be 1.111.0 times more efficient depending upon the density of plants and the nymphal population level.Fri, 07 Jun 2019 10:21:29 +0000