Forest In Missouri Research Articles

Survival and movements of brown‐headed nuthatches after translocation to the Missouri Ozarks

AbstractThe brown‐headed nuthatch (Sitta pusilla) was likely extirpated from Missouri in the early 1900s as a result of habitat loss through extensive logging. Conservation partners including the Missouri Department of Conservation, United States Forest Service, University of Missouri, and others, relocated 102 brown‐headed nuthatches from Ouachita National Forest in Arkansas to Mark Twain National Forest in Missouri in 2020 and 2021 to establish a local population. We tracked 50 individuals for 24 ± 11 (median ± SD) days after release using radio telemetry and monitored movements in relation to sex and whether a bird was captured alone or as part of a group. We examined 25‐day survival using a spatial Cormack Jolly Seber (sCJS) model to account for likely dispersal outside of our study area. All birds survived capture, transport, and release. The 25‐day survival estimate was 0.56 (95% CI = 0.36–0.78) in 2020 and 0.68 (95% CI = 0.46–0.89) in 2021. Mean total distance moved following release was 5,670 (SD = 3,407) m and mean daily movement was 243 (SD = 135) m which was less than the mean daily dispersal distance estimated from our sCJS model (420 m, SD = 221). Our short‐term monitoring suggests initial success of the translocation, but continued monitoring is needed to evaluate long‐term success. Our survival analysis approach, which included movement data, illustrates the importance of considering dispersal when estimating survival.

Responses of natural and artificial pin oak (Quercus palustris) reproduction to a sequence of silvicultural release treatments in bottomland hardwood forests in southern Missouri

Developing competitive oak advance reproduction prior to canopy disturbance is understood to be important for oak regeneration success. In the early 2000s, a study was installed in southeastern Missouri to examine the effects of midstory and understory release on natural and artificial sources of pin oak (Quercus palustris Muenchh.) advance reproduction. The findings obtained three years after midstory and understory release indicated photosynthetically active radiation increased from 3 to 15 % and a corresponding increase in density of pin oak reproduction as well as the survival and growth of both natural and artificial pin oak reproduction compared to control. In 2010, eight years after the midstory and understory was removed, three different overstory harvests were applied to release the established pin oak advance reproduction. Here, we investigated the effects of the midstory and understory removal and the subsequent overstory harvests on underplanted and naturally regenerated oak advance reproduction. We also tested effects of a later midstory release on the density of natural pin oak advance reproduction. Results indicate that the survival of bareroot pin oak seedlings increased with increasing initial basal diameter. The survival of Root Production Method (RPM®) container pin oak seedlings, however, was not dependent on the size at the time of planting. The early understory removal with triclopyr herbicide was ineffective in ensuring survival of planted pin oak seedlings. Shelterwood increased the growth of oak advance reproduction but did not eliminate competition from other species. A late release also failed to increase the growth of oak advance reproduction. Given shelterwood also favored oak competitors in our study, multiple applications of midstory and understory competition control treatments following the shelterwood treatment will be imperative for successful oak regeneration.

Winter Roosting by Eastern Red Bats in Ozark Mountain Forests of Missouri

The eastern red bat (Lasiurus borealis Müller, 1776) is a widespread species that roosts in evergreen or dead foliage suspended in trees during winter but retreats to leaf litter during colder periods. Roosting in leaf litter by eastern red bats makes them vulnerable to prescribed fires in winter. Using radio telemetry, we tracked 33 male eastern red bats to 101 winter (November–February) roosts and quantified roost locations, habitat surrounding roosts, and landscape attributes of roost locations. When roosting in trees, bats preferred oaks but generally avoided other tree species; they used pines in proportion to their availability. During colder periods, bats retreated to roosts in leaf litter where 21% suffered mortality either from predation/scavenging or unknown causes while roosting on the ground. Models of roost selection indicated that southerly aspect was the most important factor determining roost selection, and both tree- and leaf-litter roosts were predominately (≥94%) on upper south-facing slopes. Prescribed burning in late morning/early afternoon on clear days when temperatures under leaf litter are warmest in winter could reduce potential mortality by allowing faster arousal time for hibernating bats.

Differential Organic Carbon Mineralization Responses to Soil Moisture in Three Different Soil Orders Under Mixed Forested System

Soil microbial respiration is one of the largest sources of carbon (C) emissions to the atmosphere in terrestrial ecosystems, which is strongly dependent on multiple environmental variables including soil moisture. Soil moisture content is strongly dependent on soil texture, and the combined effects of texture and moisture on microbial respiration are complex and less explored. Therefore, this study examines the effects of soil moisture on the mineralization of soil organic C Soil organic carbon in three different soils, Ultisol, Alfisol and Vertisol, collected from mixed forests of Georgia, Missouri, and Texas, United States , respectively. A laboratory microcosm experiment was conducted for 90 days under different moisture regimes. Soil respiration was measured weekly, and destructive harvests were conducted at 1, 15, 60, and 90 days after incubation to determine extractable organic C (EOC), phospholipid fatty acid based microbial community, and C-acquiring hydrolytic extracellular enzyme activities (EEA). The highest cumulative respiration in Ultisol was observed at 50% water holding capacity (WHC), in Alfisol at 100% water holding capacity, and in Vertisol at 175% WHC. The trends in Extractable Organic Carbon were opposite to that of cumulative microbial respiration as the moisture levels showing the highest respiration showed the lowest EOC concentration in all soil types. Also, extracellular enzyme activities increased with increase in soil moisture in all soils, however, respiration and EEA showed a decoupled relationship in Ultisol and Alfisol soils. Soil moisture differences did not influence microbial community composition.

Fragipan Horizons: Definition, Properties, Genesis, and Influence on Soil Behavior

Many Missouri forest soils exhibit fragipans, which influence soil productivity, ecosystem services and land management. Fragipan bearing soils tend to occur where loess thickness is moderate (1 to 2 meters) or where the soil profile exhibits evidence of mass wasting of weathered limestone residuum. Consensus is consolidating around the self-weight collapse of loess and residuum after repeated wetting and desiccation. The use of gravel as an indicator of parent material differences and its correlation with fragipan development is not perfectly aligned, thus although most fragipans do exhibit a bisequal soil profile, the placement of the lithologic discontinuity is difficult given mass wasting, eluviation-illuviation, side slopes, and other soil processes that contribute to increasing the bulk density and conferring strength. Fragipan genesis is evolving; however, research involving Ecosystem Site Descriptions are a fusion of a land parcel’s soil properties, vegetational community, hydrology, and climate to guide land management. Ecological Site Descriptions associated with fragipan bearing soils are necessary, especially when making land management decisions.

Eastern US deciduous tree species respond dissimilarly to declining soil moisture but similarly to rising evaporative demand.

Hydraulic stress in plants occurs under conditions of low water availability (soil moisture; θ) and/or high atmospheric demand for water (vapor pressure deficit; D). Different species are adapted to respond to hydraulic stress by functioning along a continuum where, on one hand, they close stomata to maintain a constant leaf water potential (ΨL) (isohydric species), and on the other hand, they allow ΨL to decline (anisohydric species). Differences in water-use along this continuum are most notable during hydrologic stress, often characterized by low θ and high D; however, θ and D are often, but not necessarily, coupled at time scales of weeks or longer, and uncertainty remains about the sensitivity of different water-use strategies to these variables. We quantified the effects of both θ and D on canopy conductance (Gc) among widely distributed canopy-dominant species along the isohydric-anisohydric spectrum growing along a hydroclimatological gradient. Tree-level Gc was estimated using hourly sap flow observations from three sites in the eastern United States: a mesic forest in western North Carolina and two xeric forests in southern Indiana and Missouri. Each site experienced at least 1 year of substantial drought conditions. Our results suggest that sensitivity of Gc to θ varies across sites and species, with Gc sensitivity being greater in dry than in wet sites, and greater for isohydric compared with anisohydric species. However, once θ limitations are accounted for, sensitivity of Gc to D remains relatively constant across sites and species. While D limitations to Gc were similar across sites and species, ranging from 16 to 34% reductions, θ limitations to Gc ranged from 0 to 40%. The similarity in species sensitivity to D is encouraging from a modeling perspective, though it implies that substantial reduction to Gc will be experienced by all species in a future characterized by higher D.

Regenerating mixed bottomland hardwood forests in north Missouri: Effects of harvest treatment on structure, composition, and growth through 15 years

Bottomland forest ecosystems provide important economic and ecological benefits within the midwestern and southern United States, yet silvicultural guidelines for reaching management objectives have been poorly developed outside the southeastern region. Bottomland hardwood forests are highly productive and dynamic ecosystems that contain a multitude of herbaceous and woody plant species and can support an abundance of wildlife throughout stand development. In particular, oak species are often favored for timber and wildlife values but may occur in low abundance due, in part, to challenges with regeneration. This study was designed to examine the structure and composition of a mixed bottomland hardwood forest (elm/ash/cottonwood) in northeast Missouri in response to two regeneration harvest treatments (i.e., clearcut with reserves and basal area retention) and one unharvested control through 15 years after harvest. Results indicate that clearcutting had a greater effect on subsequent forest composition and stand development than partial harvesting. In particular, the clearcutting treatment increased the relative basal area of American elm and relative abundance (trees per hectare) of green ash. Results suggest that the regeneration harvests did not increase the abundance of oak regeneration. However, the growth rates and the size of oak stems within the regeneration cohort were comparable to competing species, suggesting the oaks within the regeneration cohort presumably originated from advance reproduction. Thus, these results support the importance for establishing oak advance reproduction prior to regeneration harvest within bottomland forests.

Natural Resource Monitoring Progression of Forest Park’s Forested Natural Areas in St. Louis, Missouri

St. Louis City, MO had 121 acres managed as woodland or forested natural areas: 98 acres in Forest Park and 13 acres in O’Fallon Park. In Forest Park, standardized Missouri forest vegetation monitoring plots were started in 1993 to develop and guide habitat management such as thinning, species richness development, etc. In 2018 and 2019, a holistic Natural Resources Management Plan (NRMP) for Forest Park provided additional recommended metrics and monitoring, some of which have already begun implementation.

Effects of forest management on vertebrates: synthesizing two decades of data from hardwood forests in Missouri, USA.

Modern forest management seeks to balance multiple social, economic, and ecological goals. Different management approaches create different types of disturbances in a forest ecosystem and thus also differ in their impacts on plants, animals, and insects. Understanding these impacts is important for conservation of forest ecosystem function, but challenging due to the large spatial and temporal scale over which management occurs. Most past research has focused on relatively small areas, short time scales, and/or a small number of species. To address this, we examined the effects of two common silvicultural systems (even and uneven aged) on abundance and richness of three vertebrate taxa (birds, small mammals, and herpetofauna) over a two-decade period in a temperate hardwood forest in Missouri, USA. The two systems removed a similar amount of biomass overall, but differed in the intensity, number, and configuration of harvests applied. We found that vertebrate population responses varied by taxa, occurred at multiple spatial scales, and were concentrated in the period following the first harvest entry. Birds generally had the largest changes in relative abundance, both positive and negative, following management. Small mammals and reptiles had smaller, but generally positive, responses; amphibians were mixed. Bird species tended to respond in the same way to both silvicultural systems, while small mammals and herpetofauna did not respond consistently. Thus, for birds, the total amount of harvest disturbance across the landscape drives population responses, while for others the size and configuration of individual harvests is likely more important. Synthesizing results across the vertebrate community at large spatial and temporal scales allows managers to better understand trade-offs when making decisions that will affect wildlife in contrasting ways.

Snail herbivory affects seedling establishment in a temperate forest in the Ozarks

Abstract Species‐specific herbivores are hypothesized to maintain plant diversity by preventing the dominance of any one plant species. However, a large proportion of herbivores have wide host ranges, and these generalists could have similar effects on plant community composition if they exhibit differences in their host preference. Here, we coupled laboratory and field experiments to test whether a common forest‐understorey snail (Neohelix alleni), a generalist herbivore, has the potential to influence forest composition through differential preference of their plant hosts. We first performed a cafeteria‐style experiment to test whether N. alleni showed feeding preferences among leaves of five tree species and one shrub common to temperate forests in Missouri, USA. We then conducted a factorial snail and deer exclusion experiment to decouple the effects of snail herbivory from those of white‐tailed deer on seedling establishment of 1‐month‐old newly germinated seedlings of these six woody species in the field. Finally, we examined whether variation in both snail feeding preference and experimentally measured effects of snails on seedling establishment across plant species were related to their relative abundance measured in a 12‐ha forest plot. In the laboratory, we found that snails preferred leaves of woody species that were less abundant in the forests relative to those species that were more common. In the forest, we found that experimental exclusion of snails had a stronger positive effect on seedling above‐ground biomass and survival over a 1‐year period than did exclusion of deer. Plant species found to be more preferred in the laboratory were also those that had lower seedling establishment in the forest due to the negative effects of snails. Synthesis. Collectively, our results suggest that greater susceptibility to snail herbivory limits seedling establishment, perhaps contributing to differences in tree species relative abundance. Although less appreciated than their insect and mammal counterparts, herbivory by snails may be significant drivers to the assembly of forest tree communities.

The Devil and the Deep Blue Lake: How Natural Area Acquisition and Stewardship Helps Protect the Major Drinking Reservoir in Northwestern Arkansas

The Arkansas Natural Heritage Commission (ANHC)'s 1225-ha Devil's Eyebrow Natural Area (DENA), located at the northern end of Beaver Lake along Indian Creek, Butler Creek, and their tributaries, is an ecologically significant site in the Ozark Highlands that falls primarily within the Beaver Lake Watershed, deemed the number-one priority watershed by Arkansas's Unified Watershed Assessments and Restoration Priorities Report due to its designation as an extraordinary water resource, the presence of imperiled aquatic species in the watershed, its role as one of the most important supplies of drinking water in the state, and its status as both an impaired water body and an interstate “water of concern.” Beaver Lake supplies drinking water to more than 420,000 people, one in eight Arkansans, and industries including the Walmart Home Office in northwest Arkansas. DENA protects 5 km of Beaver Lake frontage and 7.5 km of critical tributaries in the watershed and is part of a broader interconnected Conservation Corridor that includes Nature Conservancy preserves, Army Corps of Engineers property surrounding Beaver Lake, Hobbs State Park Conservation Area in Arkansas, and the Mark Twain National Forest and Roaring River State Park in Missouri. Water quality protection and improvement has been a critical component driving the funding of DENA, as well as both a direct and indirect focus of much of ANHC's ongoing restoration efforts on the property. Road improvements to decrease sedimentation, reforestation efforts, and feral swine removal have all served to improve water quality in the watershed. A project to improve glade habitat for several species of greatest conservation need through cedar removal has had the added benefit of providing aquatic habitat structure for fish and improving angling opportunities in Beaver Lake. This project serves as a model for conservation partnerships in critical watersheds and also highlights how efforts to directly improve water quality, as well as efforts with indirect benefits to watersheds (conceived primarily to restore terrestrial habitats), can have far-ranging benefits for ecosystems, imperiled species, and stakeholders. Here we present how the ANHC and its conservation partners have successfully used various strategies to build local support, leverage funding, engage the public, and conduct meaningful conservation at a regional scale.

First Report of Diplodia corticola Causing Stem and Branch Cankers on White Oak (Quercus alba) in Missouri, U.S.A.

An investigation of white oaks (Quercus alba) with thin crowns, branch dieback, or both was performed in Crawford and Washington counties, Missouri, during September 2015. Affected stem and branch segments were cut from each tree for examination. After debarking, isolations were performed by using a sterile scalpel to cut cubes (approximately 2 mm³) from tissues at the edges of cankers and underlying stained sapwood. Cubes were placed in quarter-strength potato dextrose agar (PDA) amended with chloramphenicol and streptomycin sulfate (100 mg/liter). A fungus frequently recovered from four of six symptomatic trees was suspected to be a Botryosphaeriaceae species based on its colony morphology, reproductive structures, and conidia (Alves et al. 2004). DNA was extracted from seven isolates, and the internal transcribed spacer (ITS) and the gene portions of nuclear ribosomal small subunit (SSU) regions were sequenced after amplification using ITS1F and ITS4 and NS1 and NS4 primers (White et al. 1990). The resulting sequences were deposited in GenBank (accession nos. MH041506 to MH041510, MH036328, and MH036329). Contigs had 100% homology with the ITS and SSU regions of multiple Diplodia corticola isolates (accession nos. KX595187.1, KT440896.1, KX463057.1, KF766239.1, and EU673206.1). Two isolates were chosen as inocula for a pathogenicity test. In a greenhouse trial, five 2-year-old seedlings were inoculated with isolate 25, and another five seedlings were inoculated with isolate 101. The fully leafed and healthy, potted seedlings were exposed to natural light. Inoculations were made by puncturing the bark of seedling stems 5 cm above the soil surface with a sterile 8-mm-diameter cork borer, peeling back the outer bark, and placing PDA bearing mycelium of either isolate into the wound. The bark was replaced and the wound wrapped with Parafilm. As a control treatment, a sterile plug of noncolonized PDA was wound inoculated 10 cm above the D. corticola inoculation site. The bark was peeled from the wounds at 8 weeks. Canker shapes were drawn on transparency film and photographed prior to measuring length and surface area with ImageJ 1.51j8 (from the National Institutes of Health). Stems were split in half and cankers measured lengthwise. Tissues were removed from the canker margin and placed in PDA for recovery of the pathogen. Vascular tissues were sampled at 0, 1, 2, and 3 cm above and below the control wound to determine if D. corticola had spread from the inoculation to the control wound. Cankers of variable sizes developed around wounds. Mean (and range) of canker areas were 4.5 cm² ± 1.4 cm² SE (2.3 to 9.1 cm²) for isolate 25 and 4.9 cm² ± 1.7 cm² SE (1.1 to 9.6 cm²) for isolate 101. The means for lengths of cankers induced by isolates 25 and 101 were 5.7 ± 0.6 and 4.6 ± 1.0 cm, respectively, when measured on stems split lengthwise. Xylem was discolored to the pith for four of five and two of five wounds inoculated with isolates 25 and 101, respectively. Cankers did not develop on wounded controls. D. corticola was recovered from canker edges from three of five seedlings for each isolate but not from sampled tissues 0, 1, 2, or 3 cm from control wounds. Hence, the pathogen did not progress far from the inoculation point. The identities of the recovered isolates were confirmed by sequencing the ITS region. This is the first report of D. corticola-caused cankers on oaks in Missouri. Earlier reports have shown that D. corticola causes cankers on Q. alba and other oak species also abundant in Missouri’s oak-dominated forests (Acimovic et al. 2016; Munck et al. 2017; Smith and Stanosz 2018). The role of D. corticola in oak dieback and mortality bears further study to understand any potential impacts on oaks that are of predominant importance in Missouri forests.

Effect of Landscape Position on the Concentration and Distribution of Soil Carbon Fractions at Busby Forest in Central Missouri

We quantified the concentrations and distribution of different soil carbon fractions – total carbon (TC), recalcitrant C measured as nonhydrolyzable carbon (NHC) and labile organic carbon measured as hydrolyzable carbon (HC), hot-water soluble C (HWC) and cold-water soluble C (CWC) at Busby forest in central Missouri. The forest soil contained large concentrations of soil organic carbon (SOC) (ranging from 26,700 to 85,000 mg C kg-1 soil); NHC (12,500 to 47,000 mg C kg-1 soil); HC (2,000 to 6,100 mg C kg-1 soil); HWC (700 to 1,550 mg C kg-1 soil); and CWC (280 to 520 mg C kg-1 soil). Soil C fractions were correlated with each other and with total organic C with correlation coefficients (r) ranging from 0.48 to 0.87. Among these correlations, NHC was significantly correlated with TC (p = 0.0027, r = 0.63), suggesting that a higher proportion of C is in the recalcitrant fraction, consequently, promoting C sequestration in these soils. Our results also showed that more than half (51.25%) of total organic C can be stabilized in the NHC fraction in these soils. Accumulation of C in the NHC fraction reflects C stabilization and sequestration in these forest soils. This information is very important for soil C modeling, as more studies attempt to include soil C fractions.

Interacting Effects of Leaf Water Potential and Biomass on Vegetation Optical Depth

AbstractRemotely sensed microwave observations of vegetation optical depth (VOD) have been widely used for examining vegetation responses to climate. Nevertheless, the relative impacts of phenological changes in leaf biomass and water stress on VOD have not been explicitly disentangled. In particular, determining whether leaf water potential (ψL) affects VOD may allow these data sets as a constraint for plant hydraulic models. Here we test the sensitivity of VOD to variations in ψL and present a conceptual framework that relates VOD to ψL and total biomass including leaves, whose dynamics are measured through leaf area index, and woody components. We used measurements of ψL from three sites across the US—a mixed deciduous forests in Indiana and Missouri and a piñon‐juniper woodland in New Mexico—to validate the conceptual model. The temporal dynamics of X‐band VOD were similar to those of the VOD signal estimated from the new conceptual model with observed ψL (R2 = 0.6–0.8). At the global scale, accounting for a combination of biomass and estimated ψL (based on satellite surface soil moisture data) increased correlations with VOD by ~ 15% and 30% compared to biomass and water potential, respectively. In wetter regions with denser and taller canopy heights, VOD has a higher correlation with leaf area index than with water stress and vice versa in drier regions. Our results demonstrate that variations in both phenology and ψL must be considered to accurately interpret the dynamics of VOD observations for ecological applications.

Role of multiple invasion mechanisms and their interaction in regulating the population dynamics of an exotic tree

Abstract Understanding the mechanisms that allow exotic species to have rapid population growth is an important step in the process of controlling existing invasions and preventing future invasions. Several hypotheses have been proposed to explain why some exotic species become invasive, the most prominent of which focus on the roles of habitat disturbance, competitors and consumers. The magnitude and direction of each of these mechanisms on population dynamics observed in previous studies is quite variable. It is possible that some of this variation results from interactions between mechanisms. We examined all of these mechanisms and their interactions on the population dynamics of the Asian exotic tree Ailanthus altissima (Simaroubaceae) in fire‐suppressed oak‐hickory forests in Missouri, USA. We experimentally reduced herbivory (using insecticide), reduced interspecific competition (plant removals), and manipulated disturbance with prescribed fire. We projected the effects of these treatments and their interactions on population dynamics by parameterizing an integral projection model. The lowest population growth rate is found where fire is absent and biotic interactions are present. Fire increased population growth rate, likely through the suppression of interspecific competitors, since competitor removal treatments increased population growth rate in the absence but not presence of fire. These results indicate that biotic resistance from interspecific competitors, more so than consumers, is important for slowing the invasion of A. altissima. Furthermore, disturbances that weaken biotic interactions, such as fire, should be used with caution when restoring habitats invaded by A. altissima. Synthesis and applications. Examining the main and interactive effects of disturbance, competition and herbivory on the population dynamics of exotic species provides a comprehensive understanding of the role of these factors in the invasion process and provides guidance for exotic species management.

Effects of fire frequency on long-term development of an oak-hickory forest in Missouri, U.S.A.

Repeated prescribed burning over long timescales has some predictable effects on forest structure and composition, but multi-decadal patterns of stand dynamics and successional change with different fire frequencies have rarely been described. We used longitudinal data from a prescribed burning study conducted over a 63-year period to quantify stand structure (stem density, basal area, and stocking) by species group, ingrowth during the first 15years of the study, and mortality during the first 35years within an oak-hickory forest of the Missouri Ozarks. The study included an unburned control treatment (Control), burning with one-year return intervals (Annual), and burning with four-year return intervals (Periodic) throughout the study duration. At the stand level, stem density decreased through time across all treatments. Periodic burning increased the rate at which mortality occurred for small-diameter stems, but after 35years, the mortality of small-diameter stems exceeded 70% across all treatments. There was little evidence of ingrowth for either burn treatment, but ingrowth increased the prevalence of non-oak species through time on the Control plots. On burned plots, basal area was maintained (Periodic) or slightly increased (Annual) during the study, primarily due to growth of trees that were present at the start of the study. However, stand stocking decreased with prescribed burning and increased in the Control plots, moving burned plots towards woodland structure while unburned plots remained as forests. Repeated burning without a fire-free interval can approximate structural conditions associated with woodlands, but suspends tree regeneration and recruitment processes necessary for canopy replacement.

Contrasting patterns of nest survival and postfledging survival in Ovenbirds and Acadian Flycatchers in Missouri forest fragments

ABSTRACT We can improve our ability to assess population viability and forecast population growth under different scenarios by understanding factors that limit population parameters in each stage of the annual cycle. Postfledging mortality rates may be as variable as nest survival across regions and fragmentation gradients, although factors that negatively impact nest survival may affect postfledging individuals in different ways. We examined nest and postfledging survival of Ovenbirds (Seiurus aurocapilla) and Acadian Flycatchers (Empidonax virescens) in mature forest fragments in central Missouri. We used an information-theoretic approach to determine support for effects of factors intrinsic to the individual or nest site, temporal factors, local vegetation characteristics, and distance to edge on survival in both stages. We also examined the effect of incorporating the resulting survival estimates on population growth. In both species, survival increased from nest to postfledging stages (Ovenbirds: 0.2...

Dynamics of a temperate deciduous forest under landscape-scale management: Implications for adaptability to climate change

Landscape forest management is an approach to meeting diverse objectives that collectively span multiple spatial scales. It is critical that we understand the long-term effects of landscape management on the structure and composition of forest tree communities to ensure that these practices are sustainable. Furthermore, it is increasingly important to also consider effects of our management within the context of anticipated environmental changes, especially future climate. This study investigated two decades of tree community dynamics within a long-term, landscape-scale management experiment located in a temperate deciduous forest in southeastern Missouri, USA. This experiment tests three alternative landscape management systems: even-aged management (EAM), uneven-aged management (UAM), and no-harvest management (NHM). Specifically, we evaluated effects of landscape management alternatives on: (1) structural and compositional dynamics of the tree communities and (2) adaptability of the tree communities to projected climate change. Changes in the abundance of dominant species under these landscape management systems suggested a prevailing successional trend on these relatively xeric, oak-dominated landscapes. In the overstory layer, there was a decrease in the abundance of red oak species (Section Lobatae), mainly black oak (Quercus velutina Lam.) and scarlet oak (Quercus coccinea Muenchh.), and an increase in white oak (Quercus alba L.) suggesting a shift to white oak dominance is underway. In the midstory and understory layers, flowering dogwood (Cornus florida L.) abundance declined substantially, while maples (Acer spp. L.) and several minor species increased. Declines in shortleaf pine populations indicated that regeneration harvesting is not regenerating this species. Experiment-wide changes in tree community composition suggest that adaptability to projected future climate may have increased over the first two decades of the MOFEP experiment under all management systems and that diverse management objectives can be realized through active management, including adaptation to climate change. However, future research is needed to test this working hypothesis and to more fully evaluate the impacts of silviculture treatments within the context of projected climate.

Changes in aboveground biomass following alternative harvesting in oak-hickory forests in the eastern USA

Abstract: Managing forest lands for the sustainability of ecosystem functions and services by developing and implementing sound silvicultural methods through site-specific practices is a core concept in ecosystem management. In this study, we used long-term data collected at the extensive plots of the Missouri Forest Ecosystem Project (MOFEP) in the southeastern Missouri Ozarks (USA) to study the changes in aboveground biomass (AGB) under three silvicultural treatments: even-aged management sites (EAM), uneven-aged management sites (UAM), and non-harvested management sites (NHM). Treatments changed the magnitude of AGB dynamics. The forests maintained an AGB of 147.9 Mg ha-1 in 1990 and it increased to 175.6 Mg ha-1 by 2009. The forests were manipulated with four treatments: clear-cut, non-harvest, uneven-aged single-tree, and uneven-aged group selection and yielded AGB values of 30.7, 139.5, 125.7, and 148.7 Mg ha-1 of AGB in 2009, respectively. Over the 18-year study period, these forests accumulated 1.78 ± 0.26 Mg ha-1 yr-1, ranging from 1.60 to 1.94 Mg ha-1 yr-1 at the NHM plots. Changes in the net AGB growth rate were contributed by different growth rates of live trees and mortality and exhibited clear intra-annual variation during the five sampling periods. We observed a decreasing contribution of Quercus velutina (black oak) AGB (~6%), an increasing trend for Q. alba (white oak), and a stable change for Q. coccinea (scarlet oak) during the study period.

New Particle Formation and Growth in an Isoprene-Dominated Ozark Forest: From Sub-5 nm to CCN-Active Sizes

Particle Investigations at a Northern Ozarks Tower: NOx, Oxidant, Isoprene Research (PINOT NOIR) were conducted in a Missouri forest dominated by isoprene emissions from May to October 2012. This study presents results of new particle formation (NPF) and the growth of new particles to cloud condensation nuclei (CCN)-active sizes (∼100 nm) observed during this field campaign. The measured sub-5 nm particles were up to ∼20,000 cm−3 during a typical NPF event. Nucleation rates J1 were relatively high (11.0 ± 10.6 cm−3 s−1), and one order of magnitude higher than formation rates of 5 nm particles (J5). Sub-5 nm particle formation events were observed during 64% of measurement days, with a high preference in biogenic volatile organic compounds (BVOCs)- and SO2-poor northwesterly (90%) air masses than in BVOCs-rich southerly air masses (13%). About 80% of sub-5 nm particle events led to the further growth. While high temperatures and high aerosol loadings in the southerly air masses were not favorable for nucleation, high BVOCs in the southerly air masses facilitated the growth of new particles to CCN-active sizes. In overall, 0.4–9.4% of the sub-5 nm particles grew to CCN-active sizes within each single NPF event. During a regional NPF event period that took place consecutively over several days, concentrations of CCN size particles increased by a factor of 4.7 in average. This enhanced production of CCN particles from new particles was commonly observed during all 13 regional NPF events during the campaign period.Copyright 2014 American Association for Aerosol Research