Organic matter accumulation is an important process that affects ecosystem function in many northern wetlands. The cotton strip assay (CSA) was used to measure the effect of harvesting and two different site preparation treatments, bedding and trenching, on organic matter decomposition in a forested wetland. A Latin square experimental design was used to determine the effect of harvesting, site preparation, and relative position within the wetland on organic matter decomposition at soil depths of 5, 10, and 20 cm. Repeated measures analysis of variance was used to test for treatment effects on organic matter decomposition, soil temperature, and soil oxidation depth. Cellulose decomposition increased at each soil depth as site disturbance increased, with bedding > trenching > whole-tree harvest > reference. The cellulose decomposition response was correlated with changes in soil temperature; the temperature coefficient Qlo equaled 6.0, which is greater than previously reported values. Position within the wetland relative to an adjoining river affected the decomposition and soil oxidation depth. Because the rate of decomposition is strongly controlled by temperature, higher rates of organic matter decay are expected to continue on harvested and regenerated sites until canopy closure reduces soil temperature.

Introduction ofEucalyptusspp. into the United States from Australia on a significant scale resulted from the gold rush into California in 1849. Numerous species were evaluated for fuel, wood products, and amenity purposes. The first recorded entry of eucalyptus into the southern United Stated was in 1878. Subsequent performance of selected species for ornamental purposes caused forest industry to visualize plantations for fiber production. That interest led the Florida Forestry Foundation to initiate species-introduction trials in 1959. The results were sufficiently promising that a contingent of forest products companies formed a cooperative to work with the USDA Forest Service, Lehigh Acres, FL, USA, on genetic improvement of selected species for fiber production. The Florida initiative caused other industrial forestry companies in the upper South to establish plantations regardless of the species or seed source. The result was invariably the same: failure. Bruce Zobel, Professor of Forestry, North Carolina State University, initiated a concerted effort to assess the potential worth of eucalyptus for plantation use. The joint industrial effort evaluated 569 sources representing 103 species over a 14-year period. The three levels of testing, screening, in-depth, and semioperational trials led to identification of some species and sources that offered promise for adaptation, but severe winter temperatures in late 1983 and early 1984 and 1985 terminated the project. Despite the failed attempt valuable silvicultural practices were ascertained that will be beneficial to other researchers and practitioners when attempts are again made to introduce the species complex into the US South.

Artificial prey, consisting of pieces of pastry placed on coloured cards, were placed on a lawn ; birds, predominantly Blue Tits, were allowed to eat them. When the prey were palatable, the birds ate more from black cards than from red, blue or grey cards. The birds ate significantly more of a "perfect" Batesian mimic than of its model, placed on an identical card, but made distasteful by soaking in a 2 1/2% solution of quinine dihydrochloride. This "discrimination" by the birds probably shows that they can see a slight yellowness in the quinine-soaked pastry. The birds showed no preference between blue, red and yellow prey when the pastry was palatable, but ate significantly more pastry from blue than from red cards when the pastry was distasteful. As this happened equally when the blue or the red prey were in the greater number, it was not due to Mullerian mimicry in the context of the experiment, but probably resulted from Batesian mimicry between the blue distasteful prey and the grey palatable prey which was intended as a control in the experiment. Thus the blue prey, acting as a Batesian model, is shown to suffer increased predation as a result of the predators' confusing it with its mimic.

A palustrine water tupelo (Nyssa aquatica L.)‐baldcy‐press (Taxodium distichum (L.) Rich.) swamp in southwestern Alabama was subjected to three types of disturbance, including helicopter logging, rubber‐tired skidder logging simulation, and helicopter logging followed by an herbicide application. An adjacent undisturbed stand served as a control area. Post‐harvest collection of sedimentation data revealed that the herbaceous and woody vegetation regrowth within the helicopter and skidded clearcut areas trapped more sediments than did the control or herbicide treatment areas. Clearcutting, followed by plant regrowth, improved the wet‐land's capacity to remove sediments from overbank flow flood waters.