Treesearch

We have compiled an exhaustive list of timberland investment management organizations (TIMOs) and timberland real estate investment trusts (REITs) and used USDA Forest Service, Forest Inventory Analysis data to quantify their acreage, distribution, dynamics, and management practices. We find that TIMOs and REITs own/manage about 16 million ac or 10% of the timberland across 11 southern states and that they manage these forests in a sustainable fashion in terms of growth-to-removals and reforestation. Furthermore, TIMOs and REITs own/manage more forest plantations than other owners and...

Row-crop and poultry production have been implicated as sources of water pollution along the Choptank River, an estuary and tributary of the Chesapeake Bay. This study examined the effects of land use, subwatershed characteristics, and climatic conditions on the water quality parameters of a subwatershed in the Choptank River watershed. The catchments within the subwatershed were defined using advanced remotely-sensed data and current geographic information system processing techniques. Water and sediment samples were collected in May–October 2009 and April–June 2010 under mostly baseflow...

It is well established that individual organisms can acclimate and adapt to temperature to optimize their functioning. However, thermal optimization of ecosystems, as an assemblage of organisms, has not been examined at broad spatial and temporal scales. Here, we compiled data from 169 globally distributed sites of eddy covariance and quantified the temperature response functions of net ecosystem exchange (NEE), an ecosystem- level property, to determine whether NEE shows thermal optimality and to explore the underlying mechanisms. We found that the temperature response of NEE followed a...

Ecology has traditionally neglected the role of people as components of ecosystems, and in particular has been largely absent from urban and other densely settled and built ecosystems. However, ecologists have finally come to realize that people and their effects are part of both seemingly wild and clearly urban ecosystems. This recognition has called for increased integration between the social sciences and biophysical sciences. This novel integration has exploited the increasingly important interfaces between urban and rural or wild systems. The frameworks of (i) patch dynamics, (ii) the...

Heterodichogamy, including protandrous (PA) and protogynous (PG) morphs, is considered a mechanism to avoid selfing and promote disassortative mating. Although morphotypes are usually present in a population at a 1:1 ratio, this ratio may be biased in a low-density population by demographic stochasticity, resulting in a deficiency of mating partners in a neighbourhood dominated by a single morph. In this study, we determined morph ratio of the heterodichogamous tree species, Juglans ailantifolia by observing flowering in a low-density population during 2 years. The morph ratio (PG: PA) of...

A nalyzing patterns of forest pest infestation is necessary for monitoring the health of forested ecosystems because of the impact insects and diseases can have on forest structure and composition, biodiversity, and species distributions (Castello and others 1995). In particular, introduced nonnative insects and diseases can extensively damage the diversity, ecology, and economy of affected areas (Brockerhoff and others 2006, Mack and others 2000). Examining pest occurrences from a landscape-scale perspective is useful, given the regional extent of many infestations and the interaction...

As development introduces competing land uses into forest and grassland landscapes, the public expresses concern for landscape patterns through headline issues such as urban sprawl and fragmentation. Resource managers need a deeper understanding of the causes and consequences of landscape patterns, to know if, where, and how to take any needed actions. The spatial arrangement of the environment affects all ecological processes within that environment; the task for resource managers is to arrange a forest or grassland in an appropriate way to provide the desired balance of biodiversity,...

Drought has significant direct and indirect impacts on forest health. In direct terms, low-to-moderate drought stress limits plant growth, while more severe drought stress reduces both growth and photosynthetic activity (Kareiva and others 1993, Mattson and Haack 1987). Indirectly, drought stress in forest communities may predispose trees to insect infestation, in some cases leading to major outbreaks (Mattson and Haack 1987). In addition, drought slows organic matter decomposition and reduces the moisture content of woody debris and other fuels, greatly increasing fire risk in wildland...

Forests cover a vast area of the United States, 303.1 million ha (749 million acres) or approximately one-third of the Nation’s land area (Smith and others 2004). These forests are of substantial ecological, economic, and social importance. Both their ecological integrity and their capacity to provide goods and services are of considerable concern in the face of a long list of threats, including insect and disease infestation, fragmentation, catastrophic fire, invasive species, and the effects of global climate change.

The Forest Health Monitoring (FHM) Program’s annual national technical report has three objectives: (1) to present forest health status and trends from a national or a multi-State regional perspective using a variety of sources, (2) to introduce new techniques for analyzing forest health data, and (3) to report results of recently completed evaluation monitoring projects funded through the FHM national program. The first section of the report, which addresses the first two objectives, is organized according to the Criteria and Indicators for the Conservation and Sustainable Management of...