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Predicting Ailanthus altissima presence across a managed forest landscape in southeast Ohio

forest Ecosystems 2019年第4期6卷 261-273页

作者： Louis R.Iverson Joanne Rebbeck Matthew P.Peters Todd Hutchinson Timothy Fox northern research station USDA Forest Service

Background: The negative impacts of the exotic tree, Ailanthus altissima(tree-of-heaven, stink tree), is spreading throughout much of the Eastern United States. When forests are disturbed, it can invade and expand quickly if seed sources are ***: We conducted studies at the highly dissected Tar Hollow State forest(THSF) in southeastern Ohio USA,where Ailanthus is widely distributed within the forest, harvests have been ongoing for decades, and prescribed fire had been applied to about a quarter of the study area. Our intention was to develop models to evaluate the relationship of Ailanthus presence to prescribed fire, harvesting activity, and other landscape characteristics, using this Ohio location as a case study. Field assessments of the demography of Ailanthus and other stand attributes(e.g., fire, harvesting, stand structure) were conducted on 267 sample plots on a 400-m grid throughout THSF,supplemented by identification of Ailanthus seed-sources via digital aerial sketch mapping during the dormant season. Statistical modeling tools Random forest(RF), Classification and Regression Trees(CART), and Maxent were used to assess relationships among attributes, then model habitats suitable for Ailanthus ***: In all, 41 variables were considered in the models, including variables related to management activities, soil characteristics, topography, and vegetation structure(derived from LiDAR). The most important predictor of Ailanthus presence was some measure of recent timber harvest, either mapped harvest history(CART) or LiDARderived canopy height(Maxent). Importantly, neither prescribed fire or soil variables appeared as important predictors of Ailanthus presence or absence in any of the models of the ***: These modeling techniques provide tools and methodologies for assessing landscapes for Ailanthus invasion, as well as those areas with higher potentials for invasion should seed sources become available. Though a case study on

关键词： Ohio Random forest CART Maxent Landscape model Non-native invasive species

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Species selection in hardwoods research: variations in baseline physiological responses of select temperate hardwood tree species

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Journal of forestry research 2013年第2期24卷 285-292页

作者： Shaneka S. Lawson Paula M. Pijut Charles H. Michler usda forest service Northern Research Station Hardwood Tree Improvement and Regeneration Center (HTIRC) Purdue University Department of forestry and Natural Resources usda forest service Northern Research Station Hardwood Tree Improvement and Regeneration Center (HTIRC)

Drought periods are becoming more extreme worldwide and the ability of plants to contribute towards atmospheric flux is being compromised. Properly functioning stomata provide an exit for water that has been absorbed by the roots, funneled into various cell parts, and eventually released into the atmosphere via transpiration. By observing the effects that weather conditions such as climate change may have on stomatal density, distribution, and functioning, it may be possible to elucidate a portion of the mechanisms trees use to survive longer periods of water stress. This study analyzed stomatal density （SD）, stomatal conductance （gs ）, CO2 assimilation （A）, instantaneous water-use efficiency （WUEi ）, and transpiration （E） rates in six native tree species in the Midwestern USA and showed that trees within the same ecotype followed similar trends, but that trees within the same family did not when exposed to identical greenhouse conditions. Naturally drought tolerant tree species demonstrated lower g s and higher WUEi , while intolerant species had higher SD. This study showed negative or no correlation between SD and g s , A, E, and WUEi and positive correlations between E and A and gs and E.

关键词： drought water stress stomatal density hardwood trees

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Application of Advection-Diffusion Routing Model to Flood Wave Propagation： A Case Study on Big Piney River, Missouri USA

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Journal of Earth Science 2016年第1期27卷 9-14页

作者： Yang Yang Theodore A. Endreny David J. Nowak usda forest service northern research station & the Davey Institute Syracuse NY 13210 USA Environmental Resource Engineering SUNY ESF Syracuse NY 132 10 USA usda forest service northern research station Syracuse NY 13210 USA

Flood wave propagation modeling is of critical importance to advancing water resources management and protecting human life and property. In this study, we investigated how the advection-diffusion routing model performed in flood wave propagation on a 16 km long downstream section of the Big Piney River, MO. Model performance was based on gaging station data at the upstream and downstream cross sections. We demonstrated with advection-diffusion theory that for small differences in watershed drainage area between the two river cross sections, inflow along the reach mainly contributes to the downstream hydrograph＇s rising limb and not to the falling limb. The downstream hydrograph＇s falling limb is primarily determined by the propagated flood wave originating at the upstream cross section. This research suggests the parameter for the advectiondiffusion routing model can be calibrated by fitting the hydrograph falling limb. Application of the advection diffusion model to the flood wave of January 29, 2013 supports our theoretical finding that the propagated flood wave determines the downstream cross section falling limb, and the model has good performance in our test examples.

关键词： advection-diffusion equation hydrograph flood wave propagation recession limb.

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Addressing nonresponse bias in forest inventory change estimation using response homogeneity classifications

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forest Ecosystems 2023年第1期10卷 125-131页

作者： James A.Westfall Mark D.Nelson U.S.forest service Northern Research StationYorkPAUSA U.S.forest service Northern Research StationSt.PaulMNUSA

Estimating amounts of change in forest resources over time is a key function of most national forest inventories(NFI). As this information is used broadly for many management and policy purposes, it is imperative that accurate estimations are made from the survey sample. Robust sampling designs are often used to help ensure representation of the population, but often the full sample is unrealized due to hazardous conditions or possibly lack of land access permission. Potentially, bias may be imparted to the sample if the nonresponse is nonrandom with respect to forest characteristics, which becomes more difficult to assess for change estimation methods that require measurements of the same sample plots at two points in time, i.e., remeasurement. To examine potential nonresponse bias in change estimates, two synthetic populations were constructed: 1) a typical NFI population consisting of both forest and nonforest plots, and 2) a population that mimics a large catastrophic disturbance event within a forested population. Comparisons of estimates under various nonresponse scenarios were made using a standard implementation of post-stratified estimation as well as an alternative approach that groups plots having similar response probabilities(response homogeneity). When using the post-stratified estimators, the amount of change was overestimated for the NFI population and was underestimated for the disturbance population, whereas the response homogeneity approach produced nearly unbiased estimates under the assumption of equal response probability within groups. These outcomes suggest that formal strategies may be needed to obtain accurate change estimates in the presence of nonrandom nonresponse.

关键词： Disturbance Post-stratification Land use conversion Sample bias

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Non-native plant species richness and influence of greenhouses and human populations in the conterminous United States

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Ecological Processes 2023年第1期12卷 388-401页

作者： Brice B.Hanberry usda forest service Rocky Mountain Research StationRapid CitySD 57702USA

Background One issue in invasive plant ecology is identification of the factors related to the invasion process that increase number of non-native *** invasion by non-native species increases,so does the probability that some non-native species will become harmful,or classified as invasive species,which disrupt natural ecosystems with attendant economic and social costs.I quantified patterns of how non-native species richness varied with vegetation types and human *** evaluate the relative importance of different predictor variables for invasion pathways in the conterminous United States,I modeled non-native plant species richness by county compared to current and historical human populations;greenhouses and nurseries;railroads,pipelines,transmission lines,and oil and gas wells;and land covers of impervious surface,development intensity categories,agriculture,and vegetation types.I also modeled these variables within vegetation types,excluding vegetation *** To summarize patterns,non-native plant species richness increased from 72 to 200 with increasing human population density *** and forest land use mosaics had the greatest mean number of non-native plant species,ranging from 121 to 166,whereas grasslands and grassland mosaics had the least number of non-native plant species,about *** modeling variable importance,all combined variables had R^(2)values of 56%(random forests regressor)and 54%(cubist regressor)for predictions of withheld observations of non-native plant species rich-ness,with greenhouse density and percent forestlands as most influential *** variables of greenhouses(R^(2)=29%),historical and current human populations(R^(2)=27%and 23%),impervious surface(25%),and medium intensity development(23%)were most associated with non-native plant species *** vegetation types,greenhouse and historical human population densities were influential variables particularly in forestlands,shrubland

关键词： Agriculture Energy forest Grassland Invasive Propagule Rural Transport Urban

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Disturbance history,species diversity,and structural complexity of a temperate deciduous forest

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Journal of forestry research 2020年第2期31卷 397-414页

作者： Jonathan D.Goode Carson R.Barefoot Justin L.Hart Daniel C.Dey Department of Geography University of AlabamaTuscaloosaAL 35487USA northern research station USDA Forest ServiceColumbiaMO 65211USA

Stand structural complexity enhancement is an increasingly popular management objective,especially on public *** stand structures are hypothesized to support a relatively high degree of native forest diversity and be more resistant and resilient to *** structures are characterized by the presence of deadwood and heterogeneity of tree-size classes and tree *** little is known about how discrete disturbance events affect structural complexity and compositional diversity in Quercus-dominated stands at fine spatial scales(***).We established 200.05 ha fixed-radius plots on the Sipsey Wilderness of William *** National forest in northern Alabama to quantify woody plant species composition and *** were mapped on each plot to quantify overstory structural complexity and compositional *** extracted two cores from all canopy Quercus spp.C 5 cm diameter at breast height to quantify age,recruitment pulses,and reconstruct canopy disturbance *** species diversity in the sampled area was 1.75 for trees,2.08 for saplings,and 1.69 for *** alba had the greatest basal area,and Ostrya virginiana had the highest *** stand exhibited a reverse J-shaped distribution with a q-factor of *** oldest Quercus dated to 1795,and the largest recruitment pulse occurred in the *** mean return interval for intermediateseverity disturbance was 38 *** we documented no relationships between disturbance frequency and compositional diversity at the neighborhood scale(0.05 ha),less frequent disturbance was associated with higher structural complexity(r^2=0.258,p=0.026)at the neighborhood *** suggest that localized disturbance increases species diversity and structural complexity,but these processes are manifest at the stand level and not at the neighborhood *** conclude that the spatial variability(***,shape,orientation,microsite conditions)is likel

关键词： Canopy gap Quercus(oak) Stand development Succession

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Afforestation,restoration and regeneration——Not all trees are created equal

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Journal of forestry research 2014年第1期25卷 3-20页

作者： Shaneka S.Lawson Charles H.Michler usda forest service Northern Research StationHardwood Tree Improvement and Regeneration Center (HTIRC)Purdue UniversityDepartment of Forestry and Natural Resources

Undulations in weather patterns have caused climate shifts of increased frequency and duration around the world. The need for additional research and model data on this pressing problem has resulted in a plethora of research groups examining a particular tree species or biome for negative effects of climate change. This review aims to （1） collect and merge recent research data on regeneration within old- and new-growth forests, （2） highlight and expand upon selected topics for additional discussion, and （3） report how shade tolerance, drought toler- ance, and inherent plasticity affect tree growth and development. Al- though shade and drought tolerance have been well studied by a number of research groups, this review reveals that in-depth analysis of a single or a few species in a given area will not generate the data required to implement a successful regeneration plan. Studies using historical accounts of previous species composition, information regarding site sea- sonality, species competition, and individual responses to drought and shade are needed to （1） develop best management plans and （2） ensure future modeling experiments are focused on a greater variety of species using more innovative methods to evaluate climate change effects.

关键词： Climate change shade tolerance drought tolerance canopy gaps invasive species

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Wood liquefaction with phenol by microwave heating and FTIR evaluation

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Journal of forestry research 2015年第4期26卷 1043-1048页

作者： Gaiyun Li Chungyun Hse Tefu Qin research Institute of Wood Industry Chinese Academy of Forestry Southern research station USDA Forest Service

We examined wood liquefaction using phenol and mixed acid catalysts with microwave heating, and compared that with similar processes that use oil bath heating. The reaction time for microwave heating to achieve a residue content was one sixth, one eighteenth, and one twenty-fourth of that from oil bath heating, respectively, for phenol to wood （P/W） ratios of 2.5/1, 2/1 and 1.5/1. A low P/W ratio tended to result in carbonization of liquefied wood due to an insufficient amount of phenol and localized microwave superheating. Fourier transform infrared spectroscopic （FTIR） evaluation of the liquefied residue, showed that the liquefaction rates of wood com- ponents differed. Hemicellulose was most susceptible to liquefaction, crystalline cellulose was most recalcitrant, and guaiacyl units the most prone to re-condensation. From FTIR, the chemical components and substitution patterns of bonded phenol were similar for both methods.

关键词： Wood liquefaction Phenol Microwaveheating Oil bath heating Fourier transform infraredspectroscopy (FTIR)

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Trajectory from beech and oak forests to eastern broadleaf forests in Indiana, USA

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Ecological Processes 2019年第1期8卷 21-28页

作者： Brice B.Hanberry usda forest service Rocky Mountain Research StationRapid CitySD 57702USA

Background:Historical forests(circa 1799 to 1846)of Indiana were predominantly composed of American beech(25%of all trees)and upland oaks(27%of all trees).I compared historical forest composition,using studies of smaller areas to approximate composition for uncommon species or genera(forest types,to current forest composition and forest types in Indiana.I also compiled published historical density estimates from small studies and estimated current density for the ***:Current forests are diverse with an even composition of many eastern broadleaf *** addition to upland oaks,which decreased to 13%of all trees,only sugar maple currently comprises greater than 10%of all *** increasing species were yellow-poplar,red maple,black cherry,and eastern *** redcedar increased from no presence to one of the most abundant ten species(≥3.5%of composition),similarly to the pine genus,becoming more common currently than American *** or oak or beech-oak forest types(≥24%of all trees)became eastern broadleaf forests,with no dominant species,and black cherry,red maple,and eastern redcedar forest types now *** of historical oak or beech forests ranged from 28 trees per hectare to 175 trees per hectare,which probably represent savannas and *** mean density of Indiana forests is 385 trees per hectare,ranging from 180 trees per hectare to 450 trees per *** forests likely contain dense layers of woody vegetation,filling the midstory and replacing herbaceous vegetation in the ground ***:Historically dominant beech and oak forests in the eastern United States have transitioned to an alternative state of closed eastern broadleaf forests due to uncontrolled establishment of many tree species.

关键词： Fire Historical Range of variability Transition

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Recent shifts in shade tolerance and disturbance traits in forests of the eastern United States

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Ecological Processes 2019年第1期8卷 391-401页

作者： Brice B.Hanberry Rocky Mountain research station USDA Forest ServiceRapid CitySD 57702USA

Background:Current forests of the eastern USA have the potential to succeed in composition to more shade-tolerant ***,long-term processes of transition from fire-tolerant tree species to fire-sensitive species and effects of current land use on forests may interfere with successional ***:I examined if forests in three regions have increased in shade tolerance and if life history strategy groups that represent response to disturbance(i.e.,fire-tolerance,early-successional species based on low shade tolerance,mid-successional species,late-successional species,and trees valued for traits related to short harvest rotations)have changed,using forest Inventory and Analysis surveys,adjusted for comparison,and generalized linear mixed models to assess approximately 30 year trends,with adjustments to equalize different survey ***:Although statistically significant,a slight increase of 2 to 4%in regional mean shade tolerance may not be ecologically *** the central East,mid-successional species replaced early-successional species and early-successional species replaced fire-tolerant oaks,resulting in an overall shift from fire-tolerant oaks to mid-successional *** fire-tolerant pine species and increased planted pine species were the major changes in the northern Southeast and Coastal ***:The successional process of increased composition by shade-tolerant species over time was overshadowed by land use changes that resulted in decreased fire-tolerant species and increased planted ***,frequent land use disturbance may continue to prevent the slow progress of compositional succession to very shade-tolerant species.

关键词： Disturbance Eastern United States Fire Land use Mesophication Oak Pine Succession Traits

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