Treesearch

Trapping of bark- and wood-infesting insects in 2015 and 2016 at multiple locations on Drummond Island in northern Lake Huron, using baited multi-funnel traps, yielded 4 species of Buprestidae, 24 Cerambycidae, and 4 Siricidae. In 2015, all funnel traps were baited with the plant volatiles α-pinene, ethanol, and cis-3-hexenol, and were either black or green in color, and placed either at heights similar to the lower canopy of nearby trees (4-5 m) or at 1-2 m above groundline. In 2016, all traps were green, hung at 1-2 m above groundline, and baited with the cerambycid pheromones fuscumol...

Agroforestry systems that integrate useful long-lived trees have been recognized for their potential in mitigating the accumulation of atmospheric fossil fuel-derived carbon (C). Black walnut (Juglans nigra) is frequently planted and cultivated in North America for its valuable lumber and edible nuts, and is highly amenable to the integration of understory crops or livestock in agroforestry systems. However, little is known about C content in black walnut trees, including the amounts of C assimilated into lignocellulosic tissues within different tree compartments. Therefore, allometric...

Ecological understanding of host–pathogen dynamics is the basis for managing wildlife diseases. Since 2008, federal, state, and provincial agencies and tribal and private organizations have collaborated on bat and white-nose syndrome (WNS) surveillance and monitoring, research, and management programs. Accordingly, scientists and managers have learned a lot about the hosts, pathogen, and dynamics of WNS. However, effective mitigation measures to combat WNS remain elusive. Host–pathogen systems are complex, and identifying ecological research priorities to improve management, choosing among...

Across the boreal forest in North America, the black spruce (Picea mariana) cover type is ecologically and economically important, occupying roughly 10 percent of Minnesota’s, USA 17.4 million acres (7.0 million hectares) of forestland. Traditionally managed through clearcut regeneration harvests, alternative silvicultural systems are being increasingly used in Canada. Here, we examine the 10- and 57-year effects of six silvicultural treatments (clearcut strips, clearcut patches, thinning, group selection, single-tree selection, shelterwood) on stand structure and dynamics in lowland black...

We compared the relative frequencies of witness trees in historical deeds to the relative frequencies of tree species found in the present forests. Changes in relative frequencies of the five dominant tree species were noted in all ecological subsections, although all species found in the past forests are represented in the present. The greatest changes across the study area were a decrease in the representation of white oak and an increase in red maple. The changes in representation by functional groups show a trend toward loss of fire-adapted species of intermediate shade intolerance...

The long-term well-being of both people and nature is achievable, assuming major changes in resource distribution and consumption at a global level. This optimistic outlook for the world requires rapid identification of major knowledge gaps that would undermine our ability to achieve a sustainable future if left unaddressed locally and regionally. Our goal was to identify the science needs that would make the biggest contribution to sustaining human society and natural systems in the Upper Midwest and Great Plains, United States. We engaged an interdisciplinary group of scientists and...

Contemporary forest management is increasingly focused on maintaining ecosystem function and services including biodiversity conservation. As a result, harvest guidelines related to retention of live trees and woody biomass (fine and coarse residue arising from harvesting) have been developed to provide benefits for wildlife, but there is much uncertainty on the effectiveness of these guidelines depending on stage of succession, retention levels, and focal taxa. We used an operational-scale, fully replicated factorial experiment to determine the effects of both tree retention (none,...

Disturbance is a central driver of forest development and ecosystem processes with variable effects within and across ecosystems. Despite the high levels of variation in disturbance severity often observed in forests following natural and anthropogenic disturbance, studies quantifying disturbance impacts often rely on categorical classifications, thus limiting opportunities to examine potential gradients in ecosystem response to a given disturbance or management regime. Given the potential increases in disturbance severity associated with global change, as well as shifts in management...

Recent global declines of pollinator populations have highlighted the importance of pollinators, which are undervalued despite essential contributions to ecosystem services. To identify critical knowledge gaps about pollinators, we describe the state of knowledge about responses of pollinators and their foraging and nesting resources to historical natural disturbances and new stressors in Great Plains grasslands and riparian ecosystems. In addition, we also provide information about pollinator management and research needs to guide effort s to sustain pollinators and by extension, flowering...

Fire is an ecological process that also has socio-economic effects. To learn more about fire occurrence, I examined relationships between land classes and about 12,000 spatially delineated large wildfires (defined here as uncontrolled fires _200 ha, although definitions vary) during 1999 to 2017 in the conterminous United States. Using random forests, extreme gradient boosting, and c5.0 classifiers, I modeled all fires, first years (1999 to 2002), last years (2014 to 2017), the eastern, central, and western United States and seven ecoregions. The three classifiers performed well (true...