Treesearch

Carbon is a building block of life, a central biogeochemical element in the earth system, and an important constituent of Earth’s atmosphere as a greenhouse gas (GhG) that powerfully influences global climate. Human activity has radically altered the global carbon balance in fundamental ways, with severe consequences for the Earth system. Vast quantities of carbon have been emitted as CO2 from oxidation of the primary carbon-containing fuels humans have used over the past two centuries, and from the destruction of natural ecosystems for agriculture, resource extraction, industry, transporta...

Fire can play an important role in peatlands by modifying plant communities and carbon (C) stocks. However, baseline disturbance data on peatland fire history are lacking in the hemi-boreal region. We sampled 29 peatlands in northern Michigan, Wisconsin, and Minnesota and used peat core records, radiocarbon dating, and infrared spectrometry to identify and date past fire events in 4 major hemi-boreal peatland ecotypes including open poor fens, treed poor fens, forested poor fens, and forested rich fens. In this region all types of poor fens had widely variable fire frequencies between...

Incorporating a citizen science approach into biological invasion management strategies can enhance biosecurity. Many citizen science projects exist to strengthen the management of forest pest and pathogen invasions within both pre- and post-border scenarios. Besides the value of citizen science initiatives for early detection and monitoring, they also contribute widely to raising awareness, informing decisions about eradication and containment efforts to minimize pest and pathogen spread, and even finding resistant plant material for restoration of landscapes degraded by disease. Overall,...

The Internet is composed of >50 billion Web pages and grows larger every day. As the number of links and specialty subject areas increases, it becomes ever more difficult to find pertinent information. For some subject areas, special purpose data crawlers continually search the Internet for specific information; examples include real estate, air travel, auto sales, and others. The use of such special purpose data crawlers (i.e., targeted crawlers and knowledge databases), also allows the collection and analysis of agricultural and forestry data. Such single-purpose crawlers can search for...

Sources of neurotoxic mercury in forests are dominated by atmospheric gaseous elemental mercury (GEM) deposition, but a dearth of direct GEM exchange measurements causes major uncertainties about processes that determine GEM sinks. Here we present three years of forest-level GEM deposition measurements in a coniferous forest and a deciduous forest in northeastern USA, along with flux partitioning into canopy and forest floor contributions. Annual GEM deposition is 13.4 ± 0.80 μgm−2 (coniferous forest) and 25.1 ± 2.4 μgm−2 (deciduous forest) dominating mercury inputs (62 and 76% of total...

Atmospheric nitrogen (N) and sulfur (S) deposition can significantly affect forest biodiversity and production by altering the growth and survival of trees. Three decades of air quality regulations in the United States have led to large reductions in oxides of N (44–81%) and S (50–99%) emissions and associated deposition. Here we evaluated the magnitude and extent of effects over 20 years from atmospheric N and S deposition on the growth and survival of 94 tree species—representing 96.4 billion trees and an average of 88% of forest basal area across the contiguous United States (CONUS)....

Great Lakes coastlines are mosaics of wetland, stream, and lake habitats, characterized by a high degree of spatial heterogeneity that may facilitate the co-occurrence of seemingly incompatible biogeochemical processes due to variation in environmental factors that favor each process. We measured nutrient limitation and rates of N2 fixation and denitrification along transects in 5 wetland–stream–lake ecotones with different nutrient loading in Lakes Superior and Huron. We hypothesized that rates of both processes would be related to nutrient limitation status, habitat type, and environmenta...

While recent studies explore the negative impacts of light pollution on arthropods, few studies investigated community-level responses to artificial light. Using an array of landscaping lights and pitfall traps, we track community composition over 15 consecutive days and nights, including a five-night pre-light period, a five-night during-light period, and a five-night post-light period. Our results highlight a trophic-level response to artificial nighttime lighting with shifts in the presence and abundance of predators, scavengers, parasites, and herbivores. We show that associated...

Shifts in plant functional groups associated with climate change have the potential to influence peatland carbon storage by altering the amount and composition of organic matter available to aquatic microbial biofilms. The goal of this study was to evaluate the potential for plant subsidies to regulate ecosystem carbon flux (CO2) by governing the relative proportion of primary producers (microalgae) and heterotrophic decomposers (heterotrophic bacteria) during aquatic biofilm development in an Alaskan fen. We evaluated biofilm composition and CO2 flux inside mesocosms with and without...

Municipalities across the United States have varied available resources to manage urban forests, resulting in substantial differences in urban forestry services and outcomes. This article reviews 32 survey-based studies that characterize U.S. municipal urban forest management program dimensions, including program components; needs and barriers; knowledge of and attitudes toward urban forests; and plans and priorities for future management. Such information is critical for agencies that support local urban forest management efforts but has not previously been systematically gathered and...