This article discusses the system of classification of forest types used by the Pwo Karen in Thung Yai Naresuan Wildlife Sanctuary
in western Thailand and the role of nontimber forest products (NTFPs), focusing on wild food plants, in Karen livelihoods.
The article argues that the Pwo Karen have two methods of forest classification, closely related to their swidden farming
practices. The first is used for forest land that has been, or can be, swiddened, and classifies forest types according to
growth conditions. The second system is used for land that is not suitable for cultivation and looks at soil properties and
slope. The article estimates the relative importance of each forest type in what concerns the collection of wild food plants.
A total of 134 wild food plant species were recorded in December 2004. They account for some 80–90% of the amount of edible
plants consumed by the Pwo Karen, and have a base value of Baht 11,505 per year, comparable to the cash incomes of many households.
The article argues that the Pwo Karen reliance on NTFPs has influenced their land-use and forest management practices. However,
by restricting the length of the fallow period, the Thai government has caused ecological changes that are challenging the
ability of the Karen to remain subsistence oriented. By ignoring shifting cultivators’ dependence on such products, the involvement
of governments in forest management, especially through restrictions imposed on swidden farming practices, is likely to have
a considerable impact on the livelihood strategies of these communities. 相似文献
From 1992–1996, 3204 artificial roosts of 9 types were placed in woodlots near Indianapolis International Airport in an effort
to provide habitat for the federally-endangered Indiana myotis (Myotis sodalis) and to determine the feasibility of using these structures to manage bats in a rapidly developing suburban area. We surveyed
these structures at least annually during 1992–1999 and found only northern myotis (Myotis septentrionalis) regularly using the structures. Four other species were occasionally found using structures including big brown bats (Eptesicus fuscus, n = 14 individuals), little brown myotis (Myotis lucifugus, n = 2), Indiana myotis (Myotis sodalis, n = 2), and one silver-haired bat (Lasionycteris noctivagans). Single, triple, and Missouri-style batboxes were almost always used, rather than the six other types of experimental roosts
that had been in place. However, after 10 years in place, it appears that Indiana bats are acclimated to boxes, as 6 of them
were being used rather regularly by Indiana myotis. Bat boxes can provide roosting habitat for some species under conditions
where few suitable roosts exist, but assuring an abundance of natural habitats is usually more desirable for conservation
of tree-roosting bats. 相似文献
Different livestock feeds manipulations have been reported to reduce the total P concentration in manure. Information on the influence of these dietary manipulation strategies on the forms of P in manure is, however, limited. This study was, therefore, conducted to investigate the effect of diet manipulation through feed micronization and enzyme supplementation on the forms of P in swine manure. Eight growing pigs were fed four diets: barley-raw pea (BRP), barley-micronized pea (BMP), barley-raw pea with enzyme (BRPE), and barley-micronized pea with enzyme (BMPE) in a 4 x 4 Latin square design. Because we are interested in the effect of enzyme cocktail and pea micronization on manure P, we did not reduce the non-phytate P with enzyme addition in this study. The fecal material and urine were collected and analyzed for total P. Fecal material was fractionated to determine the total P in H2O-, NaHCO3-, NaOH-, and HCl-extractable fractions. The total P in the residual fractions was also determined. About 98% of the total P excreted by the pigs was found in the fecal material. Inclusion of micronized pea in pig diet did not have any significant effect (p > 0.1) on either the total P or the different P fractions in the manure. The labile P (the sum of H2O-P and NaHCO3-P) was significantly reduced (p < 0.05) by the addition of enzyme to swine diets. Pigs fed the BRPE and BMPE had 14 and 18% lower labile P, respectively, compared with pigs fed the BRP. Enzyme addition to pig diets reduced not only the total P in manure, but also the labile P fraction, which is of great environmental concern. Thus, the potential of P loss to runoff and the subsequent eutrophication can be reduced by enzyme addition to pig diets. 相似文献
Russian Journal of Ecology - Abstract—The study of the effect of mycorrhiza symbiosis on the transformation of carbon and nitrogen compounds in soils is important in view of the necessity to... 相似文献
The aim of this study was to determine the bioavailability of metals in field soils contaminated with chromated copper arsenate (CCA) mixtures. The uptake and elimination kinetics of chromium, copper, and arsenic were assessed in the earthworm Eisenia andrei exposed to soils from a gradient of CCA wood preservative contamination near Hartola, Finland. In soils contaminated with 1480–1590 mg Cr/kg dry soil, 642–791 mg Cu/kg dry soil, and 850–2810 mg Ag/kg dry soil, uptake and elimination kinetics patterns were similar for Cr and Cu. Both metals were rapidly taken up and rapidly excreted by Eisenia andrei with equilibrium reached within 1 day. The metalloid As, however, showed very slow uptake and elimination in the earthworms and body concentrations did not reach equilibrium within 21 days. Bioaccumulation factors (BAF) were low for Cu and Cr (< 0.1), but high for As at 0.54–1.8. The potential risk of CCA exposure for the terrestrial ecosystem therefore is mainly due to As.
Pollution has taken on a global dimension, and the effects are most obvious in developing countries. The effects take a toll on human health, animals, and vegetation, as well as on soil, air, and water quality. The objective of this article is to discuss the current relationships among pollution, environmental quality, and human health within the frame of anthropogenic activities in developing countries. In addition to personal observations, we review relevant literature on conditions throughout the developing world and case studies on conditions and activities in Nigeria. Key findings show the significant, adverse contributions to human health and environmental risk from current waste generation and handling practices, indoor and outdoor air pollution, wastewater and effluent generation and disposal, the hazardous nature and pollution potential of wastes, and the human behaviors that contribute to pollution in developing countries. There is an urgent need to create awareness among the various segments of society of the human health hazards posed by pollution as well as a need for the comprehensive development and enforcement of appropriate policies to prevent a descent into an abyss of deteriorating human and environmental health. 相似文献
The probable source of stone moroko, Pseudorasbora parva (Temminck & Schlegel, 1846), populations in lake- and stream-type Dnieper reservoirs was revealed. The dynamics and specific growth rates of these populations over 20 years were analyzed. The dynamic phase portrait method was used to determine the timing of stages in the process of invader naturalization and the periods when its populations were in equilibrium. The potential growth rates of P. parva populations in the Kremenchug and Dneprodzerzhinsk reservoirs were estimated. 相似文献
We have carried out kinetic studies to characterize the heterogeneous decay of octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) in the presence of representative mineral dust aerosol in order to obtain a better understanding of the atmospheric fate of these siloxanes. The heterogeneous chemistry of D4 and D5 with various mineral dusts was studied in an environmental aerosol reaction chamber using FTIR absorption spectroscopy to monitor the reaction. The apparent heterogeneous uptake coefficient, γapp, for D4 and D5 with various mineral dusts was measured under dry conditions and as a function of relative humidity (RH). In addition, the effect of initial D4 and D5 concentration on the rate and yield of the reaction was examined. The uptake coefficient, γapp, for D4 and D5 was similar for the most reactive aerosols tested, with kaolinite ≈hematite > silica. Limited uptake onto carbon black and calcite surfaces was observed for either siloxane. Reaction with hematite and kaolinite resulted in multilayer coverages, suggesting extensive polymerization of D4 and D5 on the aerosol surface. 相似文献
The infrared spectrum of HCF2OCF2OCF2CF2OCF2H (CAS# 188690-77-9) has been re-measured. The integrated absorption intensity over the range 1000–1500 cm?1 measured in the present work is (6.65 ± 0.33) × 10?17 cm2 molecule?1 cm?1 in 700 Torr of air at 296 K. The radiative efficiency of HCF2OCF2OCF2CF2OCF2H is calculated to be 1.02 W m?2 ppb?1. The value reported in the 2007 Intergovernmental Panel on Climate Change (IPCC) report is approximately 35% larger reflecting what we believe to be an erroneously high value for the absorption strength of HCF2OCF2OCF2CF2OCF2H adopted by the IPCC. 相似文献