Treesearch

Field experiments of gap-based silviculture have provided inconsistent evidence that these approaches are effective in regenerating shademidtolerant oaks (Quercus spp.) and hickories (Carya spp.) in upland deciduous forests of the southern Appalachian Mountains, USA.We measured tree regeneration in a long-term field demonstration containing 13- and 30-year-old harvest gaps to evaluate the response of regeneration to group selection harvesting. Oak and hickory regeneration was mapped within the gaps to allow testing for evidence of spatial partitioning among these species. Mixed mesophytic...

Firebreaks and fuel treatments are critical means for the reduction of wildfire threat and damage to human infrastructure in forest landscapes. However, the uncertain behavior of wildfires makes the planning of firebreaks challenging, especially when available resources are insufficient to treat all locations under wildfire threat. We present a fire propagation graph approach that utilizes directed acyclic graphs to track the possible spread of wildfires from their ignition locations and estimate the impacts of firebreak placement on the possible burn area. The fire propagation graphs...

Este informe destaca el estado de los bosques de Puerto Rico (PR) según los datos del inventario forestal del 2019. La pérdida de los topes de los árboles y los deslizamientos de tierra como producto del paso de los huracanes Irma y María en el año 2017 resultaron en que la cobertura forestal en la isla grande de PR disminuyera de 54.8 en el año 2014 a 51.8 por ciento en el año 2019. El número de árboles vivos asciende a 1.3 mil millones y se registró un total de 289 especies de árboles. El árbol introducido tulipán africano (Spathodea campanulata) figura como el de mayor índice de valor...

Forest aboveground biomass (AGB) is a crucial indicator for carbon monitoring. This study presents a data-driven, cloud-based workflow for AGB density (AGBD) mapping using Global Ecosystem Dynamics Investigation (GEDI) data combined with Earth observation (EO) datasets. Focusing on the state of Alabama, the specific objectives were to: (1) evaluate and compare the effectiveness of ecoregionspecific models versus a statewide model for estimating AGBD, and (2) generate a 30-m AGBD map based on the optimal model and assess agreement with forest inventory and global-scale information. GEDI...

Understanding the response of tree species to disturbance is critical as climatic variability is projected to shift disturbance regimes, species distribution, and carbon allocation in the eastern US. Altered resource availability and microclimatic drivers bordering canopy gap edges may enhance tree growth. Our objective was to evaluate how this gap edge effect varies across dominant species groups in a southern Appalachian mixed hardwood forest. We assessed the effect of silvicultural canopy gaps, 0.15–1.09 ha in area, on overstory tree diameter growth four years after gap harvest....

Canopy openings create gradients in microclimate and can increase transpiration of individual trees bordering the gaps. This study evaluates overstory tree water use in a mature, temperate, upland hardwood forest three and four years after the establishment of 0.1 and 1 ha experimental gaps. Sap flux density (Js) was measured using thermal dissipation probes in 63 trees of dominant species groups, red maple (Acer rubrum), hickory (Carya spp.), tulip-poplar (Liriodendron tulipifera), and white oak and red oak groups (Quercus spp.), with increasing distance from experimental canopy gap edge...

As vital components of the global carbon cycle, forest ecosystems play an important role in sustainable forest management. With the new data collected and recent development of carbon equations in the region, there is a need to update the essential quantitative information about forest carbon for monitoring these vulnerable populations and making appropriate management decisions. This study aims to quantify stand-level aboveground live carbon using an alternative method among different national forests and parks in the southern Appalachian region. Hybrid models with linear mixed model and...

Crowd-sourced biodiversity data, such as those housed in the iNaturalist platform, are increasingly used to monitor species distributions. Such data represent unstructured biodiversity surveys that are generally comprised of incidental observations and do not report variation in sampling effort. These discrepancies may yield data that is incongruent with data from structured surveys. To assess whether mammalian iNaturalist data are reflective of data from traditional structured surveys, we calculated and compared measures of mammalian species richness and species pool similarity using data...

Cut stumps can be temporary hot spots of carbon emissions due to connections to decaying root systems. Drivers of variation in stump decomposition have yet to be clearly identified, including interactions with stump sprouting, an important regeneration pathway after harvest in temperate deciduous forests. The aim of this study was to identify the effects of sprouting relative to other abiotic and biotic factors on carbon emissions from cut stumps. We measured carbon dioxide (CO2) and methane (CH4) flux from the surface of cut stumps 0–4 years following a canopy gap harvest in an upland...

Open forest restoration transitions closed-canopy forests to a structure amenable to shade-intolerant species such as oak and often includes thinning or prescribed burns to promote diverse species composition. We measured how oak restoration treatments influenced ground-layer species assemblages and successional patterns in an ecologically diverse mesic hardwood forest. We tested how repeated prescribed fire, midstory herbicide applications, and the combination of shelterwood overstory harvest and prescribed fire influenced species diversity and turnover, and if species showed affinity to...