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Effects of experimental season of prescribed fire and nutrient addition on structure and function of previously grazed grassland

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Journal of Plant Ecology 2018年第4期11卷 576-584页

作者： Elizabeth H.Boughton Patrick J.Bohlen Julia H.Maki MacArthur Agro-ecology Research Center 300 Buck Island Ranch RoadLake PlacidFL 33852USA University of Central Florida Biology 4110 Libra DriveOrlandoFL 32816USA School of Natural Resources and Environment University of Florida103 Black HallPO Box 116455GainesvilleFL 32611USA

Aims Understanding the drivers of grassland structure and function fol-lowing livestock removal will inform grassland restoration and management.Here,we investigated the effects of fire and nutri-ent addition on structure and function in a subtropical semi-native grassland recently released from grazing in south-central Florida.We examined responses of soil nutrients,plant tissue nutrients,bio-mass of live,standing dead and litter,and plant species composi-tion to experimental annual prescribed fire applied during different seasons(wet season vs.dry season),and nutrient additions(N,P and N+P)over 9 years.Methods Experimental plots were set up in a randomized block split-plot design,with season of prescribed fire as the main treatment and nutrient addition as the subplot treatment.Species cover data were collected annually from 2002 to 2011 and plant tissue and plant biomass data were collected in 2002-2006 and 2011.Soil nutrients were analyzed in 2004,2006 and 2011.Important Findings Soil total phosphorus(P)levels increased substantially with P addition but were not influenced by prescribed fire.Addition of P and N led to increased P and N concentrations in live plant tissues,but prescribed fire reduced N in live tissue.Levels of tissue N were higher in all plots at the beginning of the exper-iment,an effect that was likely due to grazing activity prior to removal of livestock.Plant tissue N steadily declined over time in all plots,with annually burned plots declining faster than unburned plots.prescribed fire was an important driver of standing dead and litter biomass and was important for main-taining grass biomass and percent cover.Nutrient addition was also important:the addition of both N and P was associated with greater live biomass and woody forbs.Removal of grazing,lack of prescribed fire,and addition of N+P led to a reduction of grass biomass and a large increase in biomass of a woody forb.Annual prescribed fire promoted N loss from the system by reducing standing dead and litter,but maintained desirabl

关键词： grassland nutrient enrichment nutrient limitation prescribed fire productivity

Exploring the factors influencing the hydrological response of soil after low and high-severity fires with post-fire mulching in Mediterranean forests

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International Soil and Water Conservation Research 2023年第1期11卷 169-182页

作者： Manuel Esteban Lucas-Borja Pedro Antonio Plaza-Alvarez Xiangzhou Xu Bruno Gianmarco Carra Demetrio Antonio Zema Castlla La Mancha University School of Advanced Agricultural and Forestry Engineering.Department of Agroforestry Technology and Science and GeneticsCampus Universitario s/nE-02071AlbaceteSpain "Mediterranea"University of Reggio Calabria Department"AGRARIA"Localita Feo di VitoI-89122Reggio CalabriaItaly Institute of Environmental and Water Resources School of Hydraulic EngineeringDalian University of Technology2Ling GongGanjingziDalian116024China

Despite ample literature,the influence of the individual soil properties and covers on the hydrological response of burned soils of forests has not clearly identified.A clear understanding of the surface runoff and erosion rates altered by wildfires and prescribed fires is beneficial to identify the most suitable post-fire treatment This study has carried out a combined analysis of the hydrological response of soil and its driving factors in burned forests of Central-Eastern Spain.The pine stands of these forests were subjected to both prescribed fire and wildfire,and,in the latter case,to post-fire treatment with mulching.Moreover,simple multi-regression models are proposed to predict runoff and erosion in the experi-mental conditions.In the case of the prescribed burning,the fire had a limited impact on runoff and erosion compared to the unburned areas,due to the limited changes in soil parameters.In contrast,the wildfire increased many-fold the runoff and erosion rates,but the mulching reduced the hydrological response of the burned soils,particularly for the first two-three rainfalls after the fire.The increase in runoff and erosion after the wildfire was associated to the removal of the vegetation cover,soil water repellency,and ash left by fire;the changes in water infiltration played a minor role on runoff and erosion.The multi-regression models developed for the prescribed fire were accurate to predict the post-fire runoff coefficients.However,these models were less reliable for predictions of the mean erosion rates.The predictions of erosion after wildfire and mulching were excellent,while those of runoff were not satisfactory(except for the mean values).These results are useful to better understand the relations among the hydrological effects of fire on one side and the main soil properties and covers on the other side.Moreover,the proposed prediction models are useful to support the planning activities of forest managers and hydrologists towards a more effective conservation of forest soils.

关键词： Wildhre prescribed fire Soil cover Soil properties Soil water repellency Infiltration rate Surface runoff Soil loss Erosion

Endocrine stress response of Eastern Fence Lizards in fire-disturbed landscapes

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Current Zoology 2019年第6期65卷 643-650页

作者： Michael G.IACCHETTA K.Nichole MALONER C.M.GIENGER Department of Biology and Center of Excellence for Field Biology Austin Peay State University ClarksvilleTNUSA Department of Forestry and Natural Resources Purdue UniversityWest LafayetteINUSA Department of Pathology Microbiologyand ImmunologyVanderbilt University Medical Center NashvilleTNUSA

Landscape disturbances can alter habitat structure and resource availability,often inducing physiological responses by organisms to cope with the changing conditions.Quantifying the endocrine stress response through measurement of glucocorticoids has become an increasingly common method for determining how organisms physiologically respond to challenges imposed by their environment.We tested the hypothesis that Eastern Fence Lizards cope with fire disturbance effects by modulating their secretion of corticosterone(CORT).We measured the baseline and stress-induced plasma CORT of male Eastern Fence Lizards in a chronosequence of fire-altered habitats(recently burned,recovering from burn,and unburned).Although habitat use by lizards differed among burn treatments,including differences in use of canopy cover,leaf litter,and vegetation composition,we did not detect a significant effect of fire-induced habitat alteration on plasma CORT concentration or on body condition.In addition,we found no effect of blood draw treatment(baseline or stress-induced),body temperature,body condition,or time taken to collect blood samples on concentration of plasma CORT.Low intensity burns,which are typical of prescribed fire,may not be a sufficient stressor to alter CORT secretion in Eastern Fence Lizards(at least during the breeding season).Instead,lizards may avoid allostatic overload using behavioral responses and by selecting microsites within their environment that permit thermoregulatory opportunities necessary for optimal performance and energy assimilation.

关键词： endocrine response fire ecology habitat alteration prescribed fire reptile Sceloporus undulatus

Adult bobcat(Lynx rufus)habitat selection in a longleaf pine savanna

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Ecological Processes 2018年第1期7卷 206-217页

作者： Andrew R.Little L.Mike Conner Michael J.Chamberlain Nathan P.Nibbelink Robert J.Warren Warnell School of Forestry and Natural Resources University of Georgia180 E.Green StAthensGA 30602USA Joseph W.Jones Ecological Research Center at Ichauway NewtonGeorgia 39870USA

Background:Pine savannas are primarily managed with frequent prescribed fire(≤3 years)to promote diversity of flora and fauna,and to maintain open,park-like conditions needed by species such as the endangered red-cockaded woodpecker(Picoides borealis).However,a knowledge gap exists in our understanding of bobcat(Lynx rufus)habitat selection in longleaf pine savannas and research is warranted to direct our future management decisions.Methods:We examined bobcat habitat selection in a pine savanna managed with frequent fires at two spatial scales(i.e.,study area boundary[hereafter,landscape scale])and annual area of use[95%kernel density;local scale],and assessed effects of prescribed fire on bobcat habitat selection.Specifically,we monitored 45 bobcats(16 males and 29 females)during 2001–2007.Results:We found differential habitat selection by sex.At the landscape scale,female bobcats were closer to mixed pine-hardwoods,young pine,and secondary roads,but farther from mature pine and hardwoods stands relative to males.We found no difference in selection of agriculture,shrub-scrub,and primary roads between sexes.At the annual area of use scale,female bobcats were closer to secondary roads,but farther from agriculture and shrub-scrub relative to males.We found no difference in selection of mature pine,mixed pine-hardwoods,hardwoods,young pine,and primary roads between sexes.Bobcats primarily selected for stands burned≤1.1 years post-fire.Conclusions:Our results show that bobcats exploit a broad range of habitat types in pine landscapes managed with frequent fire and commonly use recently burned stands(≤1.1 year post-fire),suggesting prey in many areas of this system are at risk of bobcat predation.Additionally,we suggest land managers consider scale of selection by bobcats when developing habitat management strategies.

关键词： Georgia Habitat selection Lynx rufus Pinus palustris prescribed fire

Ecological succession following forest decline in a xeric oak forest of south-central United States

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Journal of Plant Ecology 2016年第4期9卷 402-409页

作者： Devin P.Bendixsen Stephen W.Hallgren Jesse A.Burton Department of Natural Resource Ecology and Management Oklahoma State University008 Ag HallStillwaterOK 74074USA Present address:Department of Biomolecular Sciences Boise State University1357 S.Brady St.BoiseID 83725USA Present address:National Park Service 2680 Natchez Trace PkwyTupeloMS 38804USA

Aims The loss of canopy trees associated with forest decline can greatly influence the species composition and structure of a forest and have major impacts on the ecosystem.We studied the changes in forest composition and structure 1 and 5 years following nearly total canopy mortality on several hundreds of hectares of xeric oak forests in south-central United States.Because the forests were within an ecotonal vegetation type composed of a mosaic of forest,savanna and grassland,we sought to learn whether forest decline areas would recover to forest or change to more open savanna and grassland conditions in the landscape pattern of vegetation.Because low intensity fire shaped the vegetation type,we sought to learn whether fire would keep the decline areas open.Methods The study was conducted in a xeric oak forest in east-central Oklahoma,USA.Randomly located vegetation and regeneration surveys were conducted in decline and non-decline stands 1 and 5 years following nearly total canopy mortality.Diameter at breast height(DBH),regeneration and sprout origin were recorded for all woody species.Important FindingsThe major canopy species post oak(Quercus stellata Wangenh.),blackjack oak(Quercus marilandica Muenchh.)and black hickory(Carya texana Buckl.)suffered 85-92%mortality;however,minor canopy components experienced limited mortality.Mortality affected all size classes of canopy trees except those below 5 cm breast height diameter.There was abundant regeneration of all species and fire seemed to maintain a high level of sprouting.Decline appeared to decrease the relative importance of stump sprouting and increase other types including root sprouts.Decline areas had abundant true seedlings,with stem origin from a root with the same diameter as the stem,which is very unusual for xeric oak forests.Regeneration height in decline areas was twice that of non-decline forests.Our findings suggest that forest decline may lead to:(i)reduced oak dominance and species change in the canopy,(ii)change in reproduction type to inc

关键词： oak decline prescribed fire seedling stump sprouts drought