Treesearch

An upward shift in elevation is one of the most conspicuous species responses to climate change. Nevertheless, downward shifts and, apparently, the absences of response have also been recently reported. Given the growing evidence of multiple responses of species distributions due to climate change and the paucity of studies in the tropics, we evaluated the response of a montane bird community to climate change, without the confounding effects of land‐use change. To test for elevational shifts, we compared the distribution of 21 avian species in 1998 and 2015 using occupancy models. The...

Climate change is warming the temperatures and lengthening the Arctic growing season with potentially important effects on plant phenology. The ability of plant species to acclimate to changing climatic conditions will dictate the level to which their spatial coverage and habitat-type dominance is different in the future. While the effect of changes in temperature on phenology and species composition have been observed at the plot and at the regional scale, a systematic assessment at medium spatial scales using new noninvasive sensor techniques has not been performed yet. At four sites...

Plant phenology studies rarely consider controlling factors other than air temperature. We evaluate here the potential significance of physical and chemical properties of soil (edaphic factors) as additional important controls on phenology. More specifically, we investigate causal connections between satellite-observed green-up dates of small forest watersheds and soil properties in the Adirondack Mountains of New York, USA. Contrary to the findings of previous studies, where edaphic controls of spring phenology were found to be marginal, our analyses show that at least three factors...

Referred to as exurbanization, amenity migration, counter-urbanization, rural sprawl, or neo-rural migration, the influx of urban migrants into rural communities has been increasingly studied over the last 50 years, both domestically and internationally. Exurbanization, a term Spectorsky coined in 1955, represents a “rural restructuring” as rural communities, environments, and economies shift from agricultural, or productivist, to other post-productivist or neo productivist landscapes While the concept of exurbanization conforms to the general idea of “sprawl”, Cadieux explains that the...

It is increasingly recognized that socio-environmental justice will not be achieved through liberal and cosmopolitical forms of activism alone. Instead, more diverse and inclusive solidarities must be achieved across political ideologies for transformative change. By engaging with one constituency often overlooked by mainstream environmentalists—rural, conservative Americans—we argue for a situated solidarity that can be forged among people whose views of nature, community, and politics differ significantly. This framework rejects totalizing expressions of global ambition that erase...

The importance of tree seedlings in determining future stand composition and structure is welldocumented in forestry literature. When planned or unanticipated overstory removal events occur, subsequent regeneration success is often linked to the number of seedlings and their height distribution. Yet, in most forest inventories, only counts of seedlings are obtained as it is too time-consuming to measure individual seedlings. To better understand the expected height distribution, models were developed to predict Weibull distribution parameters based on seedling abundance information and...

Midwestern oak savanna systems are typically defined by their open canopy and the co-existence of scattered mature oak trees and a ground layer dominated by herbaceous vegetation. The structure of these systems is thought to be primarily maintained by disturbance such as fire. In this study we examined the plant community of 21 different oak savanna sites in western Lower Michigan, U.S.A., across a coarse disturbance gradient created by different management practices. Herbaceous community composition differed significantly across a variety of management approaches, while overall diversity...

Exotic lace bugs (Hemiptera: Tingidae) have previously been evaluated for potential biocontrol of pervasive, exotic Chinese privet, Ligustrum sinense Lour. This study was conducted to determine if a native lace bug, Leptoypha mutica Say, could utilize Chinese privet and to determine the lace bug’s preferred host plant. A no-choice test determined the lace bug’s acceptance and utilization of three plant hosts: fringe tree (Chionanthus virginicus L.), swamp privet (Foresteria acuminata Michx), and Chinese privet, based on frass production, oviposition, and survival of lace bugs. Choice tests...

The native lace bug, Leptoypha mutica Say (Hemiptera: Tingidae), has demonstrated potential as an insect biological control agent of invasive Chinese privet (Ligustrum sinense Lour). To better evaluate its potential to establish on a new host, developmental biology on Chinese privet was studied at temperatures of 208C, 248C, 288C, and 328C. The complete duration of development of L. mutica from egg deposition through five instars on this previously unreported host ranged from 24.4 to 57.1 d. Estimated threshold temperatures and calculated thermal unit requirements for egg development were...

Conversion of lignocellulosic biomass to various renewable fuels, chemicals, materials, and electricity has attracted more and more interest in recent decades to decrease the dependence on fossil resources and reduce net CO2 emissions. Herein, we have developed an integrated process of biomass pretreatment for enzymatic hydrolysis of cellulose coupled with electricity generation with polyoxometalates (POMs) and ferric ion as electron mediators and proton carriers. The pretreatment is a “charging” process, and the re-oxidation of the POMs is effectively a “discharging” process. The pretreate...