Search Results (6)

Increased generation of waste, production of plastics, and poor environmental stewardship has led to an increase in floating litter. Significant efforts have been dedicated to mitigating this globally relevant issue. Depending on the location of floating litter, removal methods would vary, but usually include manual cleanups by volunteers or workers, use of heavy machinery to rake or sweep litter off beaches or roads, or passive litter collection traps. In the open ocean or streams, a common passive technique is to use booms and a collection receptacle to trap floating litter. These passive traps are usually installed to intercept floating litter; however, identifying the appropriate locations for installing these collection devices is still not fully investigated. We utilized four common criteria and fifteen sub-criteria to determine the most appropriate setup location for an in-stream collection device (Litter Gitter—Osprey Initiative, LLC, Mobile, AL, USA). Bayesian Network technology was applied to analyze these criteria comprehensively. A case study composed of multiple sites across the U.S. Gulf of Mexico Coast was used to validate the proposed approach, and propagation and sensitivity analyses were used to evaluate performance. The results show that the fifteen summarized criteria combined with the Bayesian Network approach could aid location selection and have practical potential for in-stream litter collection devices in coastal areas. Full article

This one-year study focuses on the responses of a soil environment to the implementation of traditional forest management practices in oak–hornbeam stands with the following treatments: cut (C), cut + litter raking (CR), cut + grazing (CG), cut + litter raking + grazing (CRG) and control (Ctrl). The cut was conducted in 2018 through extremely heavy thinning. In autumn of 2017 and 2018, we sampled the soils, focusing on microbial functional diversity (FD) assessments using BIOLOG Ecoplate^TM. After one season, the FD was the highest in the Ctrl stand and the lowest in the CRG stand. Furthermore, we detected significant seasonal differences in soil reaction, nitrate nitrogen content, phosphatase activity and microbial biomass among the treatments. In particular, the Ctrl stand was defined via FD indices and biochemical and biological soil properties that contrasted mainly with those of the CRG stand defined by the content of mineral nitrogen forms. The soil properties did not differ substantially in the remaining treatments. Of the 31 carbon sources defining FD, 6 were treatment-specific (putrescine, L-arginine, L-serine, L-threonine, D-cellobiose and glycogen), while the remaining carbon sources mainly displayed either uniform high or low activity across the treatments. Full article

In Slovakia, traditional orchards, like other European rural landscapes and their agricultural systems, are at long-term risk from changes in land use and management. We focused on this issue in the Nová Baňa dispersed settlement region (central Slovakia), which contains numerous traditional orchards. Management changes over the period 1949–2017 were evaluated on the basis of structured interviews conducted with the owners of 63 traditional orchards. Management measures were evaluated separately for 1949, 1970, 1991, 2000, 2007 and 2017. These data were supplemented by data on land cover over time, with an emphasis on orchards, evaluated for the years 1949, 1976, 1991 and 2017 using historical orthophoto maps. Traditional orchard management included mowing, grazing, plowing, fertilizing, and litter raking. By 2017, the management regime had changed in 92% of orchards. The use of plowing and grazing in orchards decreased, and the use of mulching has increased since 2000. From 1949 to 2017, the number of identifiable management regimes doubled; regimes consisting of a single management measure appeared, while regimes of multiple management measures decreased in frequency. Between 1949 and 2017, there was a total decrease of 38.36% in the area of traditional orchards; 31.62% of orchards remained unchanged. The largest decrease was caused by orchard conversion into grasslands (18.93%), forests (13.81%), shrubs (9.42%) and urbanized areas (8.87%). Full article

Woody biomass production can increase through establishment of non-native tree species exhibiting greater growth potential than traditional native species. Interest in growing Eucalyptus in the southeastern US has raised concern over its potential spread and invasion, which could impact ecosystem properties and functions. Within the matrix of land use where Eucalyptus establishment is being considered in the southeastern US, surrounding pine forests managed with fire represent a likely pathway for invasion. We used greenhouse and field experiments to evaluate the potential invasion risk of Eucalyptus benthamii. We were specifically interested in determining if seeds could successfully germinate in fire-maintained pine forests and if fire-return intervals influenced germination through impacts on litter accumulation and light availability. The greenhouse experiment investigated the influence of light availability on germination success, whereas the field study investigated the influence of time since fire, and thus litter accumulation and light availability, on germination success. Percent germination was similar under non-shaded controls and moderate shade, but complete shade resulted in low germination rates. Germination was lower in the field compared to the greenhouse and was influenced by litter and light availability, which varied according to fire-return intervals. Litter increased, and light availability decreased, with time since burn. Germination was negatively related to litter depth and positively related to light availability, thereby decreasing with time since fire. Germination increased with litter removal but remained positively related to light availability after litter removal. Higher germination with litter removal suggests germination is influenced by litter, but higher germination with increased light availability, regardless of raking, suggests germination is also influenced by light availability. Despite these relationships, no seedlings persisted through the growing season. The low germination rates under a variety of field conditions coupled with the lack of persistence suggests establishment may be unlikely, regardless of the surrounding land matrix. Full article

Research Highlights: The influence of litter raking and livestock grazing on the development of juvenile sessile oak and European hornbeam sprouts as well as on sessile oak standards were studied. Such experiments are very rare, especially in central Europe where these activities have been prohibited for several decades. Little is known on how these ancient management activities affect tree growth. Background and Objectives: Traditional management practices in coppice forests such as grazing and litter raking have been abandoned, but have recently been studied as to whether these practices can substantially contribute to an increase in the species diversity of coppices. The important question is, however, how these practices influence the growth of coppice-with-standards. Therefore, this study focused on the effect of grazing, litter raking, and their combination on both sprouts and adult trees in a coppice-with-standards system one year after harvest. Materials and Methods: The experiment was carried out in the area of the Training Forest Enterprise Masaryk Forest Křtiny, Czech Republic, in a forest stand dominated by sessile oak and European hornbeam. We analyzed 132 oak polycormons, 132 hornbeam polycormons, and 163 oak standards. Results: The number of sprouts per stump was affected by the stump size and management practice: (A) coppice-with-standards, litter raking, and sheep grazing; (B) coppice-with-standards and sheep grazing; (C) coppice-with-standards and litter raking; and (D) coppice-with-standards), but not by tree species. The number of the sprouts as well as their height increased with the stump size. In contrast, grazing resulted in a smaller height of the sprouts while thinner sprouts were found under a combination of grazing and raking. When comparing the species, the oak sprouts were higher and thicker when compared to the hornbeam sprouts. The increment of standards increased after stand harvest. This, however, was not the result of grazing or raking, but the response to the reduction of tree number and thus of competition between neighboring trees. Conclusions: The results showed that there were rather negative impacts from the implemented traditional management practices on the growth of sprouts. This may lead to the question of whether ecological diversity resulting from the traditional practices may prevail their negative effect on the growth of the coppices. Full article

Terrestrial arthropods in forests are engaged in vital ecosystem functions that ultimately help maintain soil productivity. Repeated disturbance can cause abrupt and irreversible changes in arthropod community composition and thereby alter trophic interactions among soil fauna. An increasingly popular means of generating income from pine plantations in the Southeastern U.S. is annual raking to collect pine litter. We raked litter once per year for three consecutive years in the pine plantations of three different species (loblolly, Pinus taeda; longleaf, P. palustris; and slash, P. elliottii). We sampled arthropods quarterly for three years in raked and un-raked pine stands to assess temporal shifts in abundance among dominant orders of arthropods. Effects varied greatly among orders of arthropods, among timber types, and among years. Distinct trends over time were apparent among orders that occupied both high trophic positions (predators) and low trophic positions (fungivores, detritivores). Multivariate analyses demonstrated that raking caused stronger shifts in arthropod community composition in longleaf and loblolly than slash pine stands. Results highlight the role of pine litter in shaping terrestrial arthropod communities, and imply that repeated removal of pine straw during consecutive years is likely to have unintended consequences on arthropod communities that exacerbate over time. Full article