Search Results

Researchers with the Missouri Department of Conservation, the Missouri Department of Natural Resources, the U.S. Forest Service, and cooperating universities (University of Missouri-Columbia, University of Missouri-St. Louis, Michigan Technological University, and University of Tennessee-Chattanooga) are conducting a bold experiment to examine the long-term, large-scale impacts of forest management practices on the biotic and abiotic components of the oak-hickory forests of southern Missouri. The Missouri Ozark Forest Ecosystem Project (MOFEP) aims to conduct a controlled experiment to document the effects of typical forest management practices on the numbers and types of forest plants and animals, including amphibians. Drift fence arrays are chosen as the MOFEP technique for trapping amphibians. In this experiment, the impact of the forest management practices of clearcutting (technically called even-aged management) and select tree cutting (called uneven-aged management) is examined. MOFEP is unique both in its duration and its scale — data will be collected for the next 100+ years and on the landscape scale of 1,000-acre forests.

This chapter examines the long-term impact of clearcutting on the understory herbaceous community in southern Appalachian cove forests. It addresses the following questions: What are the forces that determine community structure, especially in response to disturbance? When disturbed, is the community resilient? What aspects of the community change? How long does it take to recover from past disturbances? Are recovering communities structured similarly to undisturbed communities? The chapter shows that understory herb communities do not return to their pre-disturbance states even after 100–150 years of recovery, according to both patterns and processes. Both species richness and abundance were greater in old-growth forests than mature forests, and species composition differed significantly between the two. Importantly, the study showed that diversity in the herb layer varies with spatial scales.

The Fernow Experimental Forest (FEF) was established to conduct research in forest and watershed management in the central Appalachians. The 1868-ha FEF, located south of Parsons, West Virginia, is administered by the Northern Research Station of the USDA Forest Service and provides a valuable point of comparison with Coweeta Hydrologic Laboratory (CHL), located in the southern Appalachians. This chapter summarizes responses to clearcutting on four watersheds at FEF and compares the results to those from clearcutting on CHL Watershed 7 (WS 7). Comparisons between Fernow and Coweeta clear-cut watersheds reveal a number of consistencies, including rapid regeneration/revegetation of harvested watersheds and short-term increases in annual streamflow due to clearcutting. The differences observed between the two sites were relatively small and mostly dealt with rates of revegetation and nutrient cycling. These are probably due to differences in climate, atmospheric deposition, and soil depth.

The Hubbard Brook Experimental Forest (HBEF) in central New Hampshire, in the heart of the White Mountains, was established in 1955, two decades after Coweeta Hydrologic Laboratory (CHL). However, research objectives at both sites have long been similar, that is, to understand hydrologic and nutrient cycling processes for forest ecosystems, and to determine responses to natural and human disturbances. This chapter summarizes the responses to intensive cuttings on three watersheds at HBEF and compares the results with those from the clearcutting on Watershed 7 (WS 7) at CHL. Despite significant differences in site characteristics between CHL and HBEF, responses to intensive harvests showed several similarities. Among these are that harvested sites regenerated rapidly, with opportunistic and pioneer species dominating regrowth for the first 20+ years after harvest. Water yield also increased during the early years after harvest but declined rapidly with regrowth.

This chapter aims to (i) compare fluxes of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and dissolved organic phosphorus (DOP) in a clearcut area and an adjacent mature reference area; (ii) determine whether concentrations of dissolved organic nutrients or inorganic nutrients were greater in clearcut areas than in reference areas; and (iii) identify the strata where the greatest net leaching and deposition occur. It shows that fluxes of DOC, DON, and DOP in all strata were greater in cut plots than in uncut plots. In the cut plots, fluxes of the organic forms of nutrients exceeded those of the inorganic forms. It is hypothesized that the well-recognized retention mechanisms for inorganic nutrients (e.g. uptake by the roots of stump sprouts, adsorption of ions, and immobilization) combined with geochemical adsorption of dissolved organic matter, efficiently buffer against the leaching of either soluble inorganic or organic nutrients after clearcutting.

This chapter describes the assessment of dissolved organic carbon (DOC) concentrations in two streams: Big Hurricane Branch, which drains Watershed 7 (WS 7) and was clearcut using cable logging in 1977; and Hugh White Creek which drains WS 14, one of the long-term reference watersheds at Coweeta Hydrologic Laboratory. The study aims to determine whether DOC concentrations in Big Hurricane Branch became more similar to those in the reference stream as the forest on the clearcut watershed recovered; to describe seasonal and interannual patterns of DOC concentration and transport in the two streams; and to explore potential causes of the seasonal and interannual patterns observed.

Most of the forest on Watershed (WS) 7 was cut and left on site to decompose. This chapter describes the rate and manner of wood decomposition and quantifies the fluxes from decaying wood to the forest floor on WS 7. In doing so, it makes the case that wood and its process of decomposition contributes to ecosystem stability. It also reviews some of the history of wood decomposition and places the results in the context of detrital organic matter pools on the watershed. It shows that wood contributed to ecosystem resilience through woody debris decomposition and the subsequent flux of both organic matter and nutrients to the forest floor, increasing the nutrient content of detrital pools and supplying nutrients to the regrowing forest. As organic matter in wood decomposed into CO₂ and was lost from the system, the regrowth of new vegetation fixed CO₂ into new plant matter.

Studies on decomposition in Watershed 2 (WS 2) and WS 7 at Coweeta Hydrologic Laboratory have concentrated on tracking changes in this process subsequent to the clearcut in 1977. An assumption was made that microarthropod abundance was similar on WS 2 and WS 7 at Coweeta before WS 7 was cable logged in 1977. After a year, abundance was reduced by more than 50 percent in the clearcut watershed compared with the control. Blair and Crossley (1988) suggested that microarthropod abundance, which remained 28 percent lower in the clearcut area than in the control, may have been responsible for decreased decomposition rates. This chapter presents a study, conducted two decades after the clearcut, that reinvestigated the decomposition dynamics of the litter types examined by Blair and Crossley (1988). It shows that ecosystem successional development at WS 7 was not assisted by restoration management. Decomposition rates and the biota that contribute to the decomposition process are linked. The recovery of the former is dependent to some extent on the recovery of the latter. Even in the absence of management, the decomposer subsystem in a hardwood forest re-established itself after two decades.

This chapter examines the impact of the Watershed 7 (WS 7) clearcut on canopy arthropods. Given the expected shift in plant types, how would the community of arthropods respond? Would the increase in herbaceous vegetation influence the community of insects on the tree vegetation? Would the regrowth foliage tissue be more tender, perhaps engendering outbreaks of defoliators? And, could those factors most responsible for the development of the insect community be isolated? It is shown that regrowth tree foliage one year after the clearcut had a greater mass of chewing herbivores, sucking herbivores, and omnivores, such as caterpillars, aphids, and ants, respectively, compared to the adjacent control watershed. Predators, such as spiders and predaceous beetles, decreased. Differences for black locust were especially marked, with greater densities seen especially for sucking herbivores and omnivores, particularly ants.