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- Getachew, Merkebu, et al.
(författare)
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Effects of shade tree species on soil biogeochemistry and coffee bean quality in plantation coffee
- 2023
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Ingår i: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 347
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Tidskriftsartikel (refereegranskat)abstract
- Shade trees are used in many coffee production systems across the globe. Beyond the benefits on biodiversity conservation, climate buffering, carbon sequestration and pathogen regulation, shade trees can impact the soil nutrient status via, for instance, litter inputs and nitrogen fixation. Since soil nutrients affect coffee quality and taste, there is also a potential indirect effect of shade tree species on coffee quality. Yet, in spite of the potentially large impact of shade tree species, quantitative data on the effects of shade trees on (i) soil biogeochemistry and (ii) the associated coffee bean quality remain scarce. To what extent four widely used shade trees species (Acacia abyssinica L., Albizia gummifera L., Cordia africana L. and Croton macrostachyus L.) in a plantation coffee agroforestry system impact soil biogeochemistry, and how this in turn affects coffee quality, measured as cupping scores and bean size. A significant negative impact of N-fixing shade tree species on soil pH and base cation concentrations was found. Plant-available and total phosphorus was enhanced by the presence of Albizia gummifera L. Thus, the present findings demonstrate that careful selection and integration of shade tree species such as Acacia abyssinica L. and Albizia gummifera L. into coffee production systems is a good practice for sustaining soil chemical properties in coffee agroecosystem. Despite the impacts on soil chemical characteristics, the shade tree species had no effect on coffee cup quality but did affect the bean mass. In this particular study, an attempt was made to quantify the impacts of widely used shade tree species on soil biogeochemistry and the subsequent effect on coffee bean quality in a plantation agroforestry system over the course of one season in southwest Ethiopia. However, it might be feasible to accommodate both relatively sparse time-series experimental data consisting of coffee farms from plantations and smallholders, which needs to be the goal of future research to accurately examine the impacts on the outcome variables.
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| 2. |
- Verheyen, Kris, et al.
(författare)
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201 Combining Biodiversity Resurveys across Regions to Advance Global Change Research
- 2017
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Ingår i: BioScience. - : Oxford University Press (OUP). - 0006-3568 .- 1525-3244. ; 67:1, s. 73-83
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Tidskriftsartikel (refereegranskat)abstract
- More and more ecologists have started to resurvey communities sampled in earlier decades to determine long-term shifts in community composition and infer the likely drivers of the ecological changes observed. However, to assess the relative importance of and interactions among multiple drivers, joint analyses of resurvey data from many regions spanning large environmental gradients are needed. In this article, we illustrate how combining resurvey data from multiple regions can increase the likelihood of driver orthogonality within the design and show that repeatedly surveying across multiple regions provides higher representativeness and comprehensiveness, allowing us to answer more completely a broader range of questions. We provide general guidelines to aid the implementation of multiregion resurvey databases. In so doing, we aim to encourage resurvey database development across other community types and biomes to advance global environmental change research.
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