Treesearch

Context. No single model can capture the complex species range dynamics under changing climates--hence the need for a combination approach that addresses management concerns. Objective. A multistage approach is illustrated to manage forested landscapes under climate change. We combine a tree species habitat model--DISTRIB II, a species colonization model--SHIFT, and knowledgebased scoring system--MODFACs, to illustrate a decision support framework. Methods. Using shortleaf pine (Pinus echinata) and sugar maple (Acer saccharum) as examples, we project suitable habitats under two future...

The conversion of agriculture lands to forest has been occurring in parts of North America for decades. The legacy of management activity during this transition is reflected in soil physical and chemical properties years after abandonment. This study was conducted at the Smithsonian Environmental Research Center, Maryland, USA, to determine land-use history and forest age effects on soil nutrients, carbon, pH, and bulk density. Soils in young and old successional forests and forests with no evidence of historical disturbance were sampled. The young forest stands were abandoned from...

A long-term assumption in ecology is that species distributions correspond with their niche requirements, but evidence that species can persist in unsuitable habitat for centuries undermines the link between species and habitat. Moreover, species may be more dependent on mutualist partners than specific habitats. Most evidence connecting indigenous cultures with plant dispersal is anecdotal, but historical records suggest that Native Americans transported and cultivated many species, including Gleditsia triacanthos ("Honey locust"). Gleditsia triacanthos was an important medicinal/culinary...

Mangroves are well-known for their numerous ecosystem services, including sequestering a significant carbon stock, with soils accounting for the largest pool. The soil carbon pool is dependent on the carbon content and bulk density. Our objective was to assess the spatial variability of mangrove soil physical and chemical properties within the Zambezi River Delta and determine whether it may be associated with geomorphic setting. Plots were classified as one of four geomorphic settings: seaward fringe, creek, riverine, and interior. Additionally, we attempted to determine the source(s) of...

Tropical wetland ecosystems, especially mangroves and peatlands, are carbon (C) rich ecosystems. Globally, tropical mangroves store about 20 PgC, however, deforestation has contributed 10 % of the total global emissions from tropical deforestation, even though mangroves account for only about 0.7 % of the world’s tropical forest area (Donato et al. 2011). Meanwhile, tropical peatlands store 191 PgC or approximately 33 % of global peatland C (Post et al. 1982; Page and Rieley 1999). This disproportionate capacity of tropical wetlands to sequester and store C make them a critical component...

Oaks (Quercus spp.) grown in monoculture plantations often do not develop high-grade boles because all the trees grow at similar rates and crown stratification does not occur resulting in persistent branches and poor bole quality. The use of trainer species in mixed species plantations could promote interspecific competition and crown stratification leading to higher grade oak boles. As part of a larger, long-term study investigating growth, crown interactions, and bole development of cherrybark oak (Quercus pagoda) with several species at different planting densities, yellow-poplar...

Climate change and forest disturbances are threatening the ability of forested mountain watersheds to provide the clean, reliable, and abundant fresh water necessary to support aquatic ecosystems and a growing human population. Here we used 76 years of water yield, climate, and field plot vegetation measurements in six unmanaged, reference watersheds in the southern Appalachian Mountains of North Carolina, USA to determine whether water yield has changed over time, and to examine and attribute the causal mechanisms of change. We found that annual water yield increased in some watersheds...

The relationships among drought, surface water flow, and groundwater recharge are not straightforward for most forest ecosystems due to the strong role that vegetation plays in the forest water balance. Hydrologic responses to drought can be either mitigated or exacerbated by forest vegetation depending upon vegetation water use and how forest population dynamics respond to drought. Understanding how drought impacts ecosystems requires understanding how drought impacts ecohydrological processes. Because different species and functional groups vary in their ecophysiological traits that...

Forests, and the people who depend on them, are under enormous pressure worldwide. Deforestation in many parts of the world continues at an alarming pace, the result of agricultural conversion for food and industrial crops such as oil palm, livestock production, mining, and energy and industrial infrastructure development. Forest degradation is even more widespread, leading to more gradual losses of biodiversity, forest structure, ecological functioning, and provision of ecosystem services. Biodiversity loss, climate change, pollution, water shortages, and environmental conflicts lessen...

Good seedlings, proper planting, and competition control normally result in successful hardwood planting. However, other factors can have serious impact on planting success, such as the impact of flooding, freezing, and the American beaver (Castor canadensis). In 2014, three planting stocks of Nuttall oak (Quercus nuttallii) and Shumard oak (Quercus shumardii) were planted on two sites in southern Mississippi and survival checks were conducted monthly. The first check revealed that only three seedlings of the containerized stock had survived. Subsequent nursery inquiries revealed that many...