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11.
Abstract: Studies have documented biodiversity losses due to intensification of coffee management (reduction in canopy richness and complexity). Nevertheless, questions remain regarding relative sensitivity of different taxa, habitat specialists, and functional groups, and whether implications for biodiversity conservation vary across regions. We quantitatively reviewed data from ant, bird, and tree biodiversity studies in coffee agroecosystems to address the following questions: Does species richness decline with intensification or with individual vegetation characteristics? Are there significant losses of species richness in coffee‐management systems compared with forests? Is species loss greater for forest species or for particular functional groups? and Are ants or birds more strongly affected by intensification? Across studies, ant and bird richness declined with management intensification and with changes in vegetation. Species richness of all ants and birds and of forest ant and bird species was lower in most coffee agroecosystems than in forests, but rustic coffee (grown under native forest canopies) had equal or greater ant and bird richness than nearby forests. Sun coffee (grown without canopy trees) sustained the highest species losses, and species loss of forest ant, bird, and tree species increased with management intensity. Losses of ant and bird species were similar, although losses of forest ants were more drastic in rustic coffee. Richness of migratory birds and of birds that forage across vegetation strata was less affected by intensification than richness of resident, canopy, and understory bird species. Rustic farms protected more species than other coffee systems, and loss of species depended greatly on habitat specialization and functional traits. We recommend that forest be protected, rustic coffee be promoted, and intensive coffee farms be restored by augmenting native tree density and richness and allowing growth of epiphytes. We also recommend that future research focus on potential trade‐offs between biodiversity conservation and farmer livelihoods stemming from coffee production.  相似文献   
12.
阐述了铸造落砂工部粉尘的产生及对环境的污染.通过沈阳第一机床厂铸造车间大型工段除尘改造,介绍了利用密闭式除尘罩对落砂机进行除尘及选择适合的集尘装置,组成合理的除尘系统,取得了较好的除尘效果.还介绍了对灰尘的排放加强管理,设计了升降式卸灰溜槽,指定专用罐车外运灰尘,使环境得到了净化.  相似文献   
13.
This paper describes a method for quantification of sixteen polycyclic aromatic hydrocarbons (PAHs) in tea and coffee samples of Mumbai City with the help of reversed phase high performance liquid chromatography with UV-VIS detector. This method is based on liquid–liquid extraction followed by clean up with C-18 cartridge. Concentration of total PAHs in different brands of tea and coffee samples varied from 18.79 to 31.37 μg/L and from 16.47 to 18.24 μg/L, respectively. Mean concentration of total PAHs was 27.56 μg/L in tea and 17.20 μg/L in coffee. Recoveries at different concentration levels were higher than 68% in samples of tea and coffee. Detection limit was found to be low (0.0006 ng) for anthracene and highest (0.174 ng) for naphthalene with relative standard deviation between 0.4%–7%.  相似文献   
14.
利用热重分析法研究了城市污水污泥、咖啡渣在不同气氛及不同混合比例条件下,其单一样及其混合样的燃烧特性,计算了各类综合燃烧特性指数,并对他们的燃烧动力学进行了建模.结果表明,单一污泥样品的燃烧曲线存在3个明显的失重峰,分别对应于水分的析出、挥发分的析出燃烧、难燃有机物及固定碳的燃烧.咖啡渣燃烧则分为挥发分析出及燃烧、挥发分的燃尽和固定碳燃烧两个明显阶段.污泥中混合咖啡渣后,污泥燃烧特性有所改善,其中混合30%咖啡渣后污泥的挥发分释放特性指数D、可燃性指数C、燃尽指数Cb、综合燃烧特性指数S分别增加了1.5、1.0、0.3、1.7倍,与燃烧气氛N_2/O_2相比,污泥和咖啡渣混合试样在CO_2/O_2气氛中燃烧受到了一定的抑制作用.利用Coats-Redfern积分法计算得到不同条件下污泥、咖啡渣及其混合样燃烧的质量平均表观活化能(Em)分别在30.49~36.72 k J·mol~(-1)、63.07~118.90 k J·mol~(-1)、37.80~44.49k J·mol~(-1)范围.可以分别用f(α)=(1-α)0.5、f(α)=(1-α)2描述污泥、咖啡渣及其混合样燃烧的第一挥发分峰前及峰后的燃烧机理.  相似文献   
15.
Social relations associated with conventional agricultural exports find their origins in long term associations based on business, family, and class alliances. Working outside these boundaries presents a host of challenges, especially where small producers with little economic or political power are concerned. Yet, in many developing countries, alternative trade organizations (ATOs) based on philosophies of social justice and/or environmental well-being are carving out spaces alongside traditional agricultural export sectors by establishing new channels of trade and marketing. Coffee provides a case in point, with the fair trade and certified organic movements making inroads into the market place. In their own ways, these movements represent a type of economic and social restructuring from below, drawing upon and developing linkages beyond the traditional boundaries of how coffee is produced and traded. An examination of the philosophies of the fair trade and organic coffee movements reveal that the philosophical underpinnings of both certified organic and fair-trade coffee run counter to the historical concerns of coffee production and trade. Associations of small producers involved in these coffees face stiff challenges – both internal and external to their groups. More work, especially in situ fieldwork aimed at uncovering the challenges, benefits, tensions, and successes, is needed to understand better the ways these networks operate in the dynamic agro-food complex.  相似文献   
16.
17.
Abstract: Quality of the agricultural matrix profoundly affects biodiversity and dispersal in agricultural areas. Vegetatively complex coffee agroecosystems maintain species richness at larger distances from the forest. Epiphytes colonize canopy trees and provide resources for birds and insects and thus effects of agricultural production on epiphytes may affect other species. We compared diversity, composition, and vertical stratification of epiphytes in a forest fragment and in two coffee farms differing in management intensity in southern Mexico. We also examined spatial distribution of epiphytes with respect to the forest fragment to examine quality of the two agricultural matrix types for epiphyte conservation. We sampled vascular epiphytes in a forest fragment, a shade polyculture farm, and a shade monoculture farm at 100 m, 200 m, and 400 m from the forest. Epiphyte and orchid richness was greater in the forest than in the monoculture but richness was similar in the forest and polyculture farm. Epiphyte species composition differed with habitat type, but not with distance from the forest. In the forest, epiphytes were distributed throughout tree canopies, but in the farms, epiphytes were primarily found on trunks and larger branches. Epiphyte richness and species similarity to forest species declined with distance from the forest fragment in the monoculture, but richness and similarity to forest species did not decline with distance from forest in the polyculture. This suggests polyculture coffee has greater conservation value. In contrast, monoculture coffee is likely a sink habitat for epiphytes dispersing from forests into coffee. Coffee farms differ from forests in terms of the habitat they provide and species composition, thus protecting forest fragments is essential for epiphyte conservation. Nonetheless, in agricultural landscapes, vegetatively complex coffee farms may contribute to conservation of epiphytes more than other agricultural land uses.  相似文献   
18.
Abstract:  Many tropical forests have been converted for agri- or silviculture or a combination of both (agroforestry). Conservation at a landscape scale requires an understanding of the distribution and abundance of native biodiversity in these converted natural ecosystems, of which the knowledge is especially poor for African agroecosystems. We compared species density and species composition of four plant groups (trees and shrubs, epiphytic vascular plants, mosses, and liverworts) among three arboreal land-use types in southwestern Ethiopia (montane rainforest fragments, shade-tree coffee home gardens, and exotic tree plantations). Species density was significantly higher in forests than in coffee home gardens for all plant groups and in exotic tree plantations for all groups except mosses. Home gardens had more vascular epiphytic species than plantations, whereas the reverse was true for mosses and liverworts. The species composition of the forest plots was sometimes more similar to home-garden plots than plantation plots and sometimes vice versa. Fifteen forest plots had, however, cumulatively more species than a random selection of 15 nonforest (coffee home garden and plantation) plots, even if the 2 plot types complemented each other in terms of habitats for forest plants. Tree plantations dominated by Eucalyptus had many small trees and shrubs in common with forests, whereas plantations with Cupressus were important substrates for forests mosses and liverworts. Our results illustrate the importance of undisturbed forests habitats for conservation of species at a landscape scale and that different human-made land-use types may complement each other in their capacity as additional habitats for forest species.  相似文献   
19.
Abstract: Determining the permeability of different types of landscape matrices to animal movement is essential for conserving populations in fragmented landscapes. We evaluated the effects of habitat patch size and matrix type on diversity, isolation, and dispersal of ithomiine butterflies in forest fragments surrounded by coffee agroecosystems in the Colombian Andes. Because ithomiines prefer a shaded understory, we expected the highest diversity and abundance in large fragments surrounded by shade coffee and the lowest in small fragments surrounded by sun coffee. We also thought shade coffee would favor butterfly dispersal and immigration into forest patches. We marked 9675 butterflies of 39 species in 12 forest patches over a year. Microclimate conditions were more similar to the forest interior in the shade‐coffee matrix than in the sun‐coffee matrix, but patch size and matrix type did not affect species richness and abundance in forest fragments. Furthermore, age structure and temporal recruitment patterns of the butterfly community were similar in all fragments, independent of patch size or matrix type. There were no differences in the numbers of butterflies flying in the matrices at two distances from the forest patch, but their behavior differed. Flight in the sun‐coffee matrix was rapid and directional, whereas butterflies in shade‐coffee matrix flew slowly. Seven out of 130 recaptured butterflies immigrated into patches in the shade‐coffee matrix, and one immigrated into a patch surrounded by sun coffee. Although the shade‐coffee matrix facilitated movement in the landscape, sun‐coffee matrix was not impermeable to butterflies. Ithomiines exhibited behavioral plasticity in habitat use and high mobility. These traits favor their persistence in heterogeneous landscapes, opening opportunities for their conservation. Understanding the dynamics and resource requirements of different organisms in rural landscapes is critical for identifying management options that address both animals’ and farmers’ needs.  相似文献   
20.
Polycyclic aromatic hydrocarbons (PAHs) are suspected to be carcinogenic and mutagenic. This study describes the presence of PAHs in light, medium and dark roasted coffee including instant and decaffeinated brands. Total PAHs concentration was related to the degree of roasting with light roasted coffee showing the least and dark roasted coffee showing the highest level. Both instant and decaffeinated coffee brand showed lower levels of PAHs. Naphthalene, acenaphthylene, pyrene and chrysene were the most abundant individual isomers. The concentrations ranged from 0 to 561 ng g?1 for naphthalene, 0 to 512 ng g?1 for acenaphthylene, 60 to 459 ng g?1 for pyrene and 56 to 371 ng g?1 for chrysene. Thus, roasting conditions should be controlled to avoid the formation of PAHs due to their suspected carcinogenic and mutagenic properties.  相似文献   
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