1. Agroforestry systems are refuges for biodiversity and provide multiple ecosystem functions and services. Diverse multispecies shade tree canopies are increasingly replaced by monospecific shade, often dominated by non-native tree species. The loss of tree diversity and the nature of the dominating tree can have strong implications for ecosystem functions, e.g. nutrient cycling ultimately reducing crop production. 2. To understand direct and indirect impacts of shade trees on nutrient cycling and crop production, we studied coffee agroforestry systems in India along a gradient from native multispecies canopies to Grevillea robusta (Proteaceae) -dominated canopy cover. We identified 25 agroforests, across a broad rainfall and management gradient and assessed litter quantity and quality, decomposition, nutrient release, soil fertility and coffee nutrient limitations. 3. Increasing G. robusta dominance affected nutrient cycling predominantly by; (1) changing of litter phenology, (2) reducing phosphorus (P), potassium (K), magnesium (Mg), boron (B), and zinc (Zn) inputs via litterfall, decelerated litter decomposition and immobilization of P and Zn due to low quality litter, (3) reducing soil carbon (C) and micronutrients (especially sulphur (S), Mg and B). Coffee plants were deficient in several nutrients (nitrogen (N), calcium (Ca), manganese (Mn), Mg and S in organic and B in conventional management). (4) Overall G. robusta dominated agroforests were characterized by a reduction of P cycling due to low inputs, strong immobilization while decomposition and antagonistic effects on its release in litter mixtures with coffee. 4. Synthesis and applications. The conversion of shade cover in coffee agroforestry systems from diverse tree canopies to canopies dominated by Grevillea robusta (Proteaceae) reduces the inputs and cycling of several micro- and macronutrients. Soil fertility is therefore expected to decline in G. robusta dominated systems, with likely impacts on coffee production. These negative effects might increase under the longer dry periods projected by regional climate change scenarios due to the pronounced litter phenology of G. robusta. Maintaining diverse shade canopies can more effectively sustain micro- and macronutrients in a more seasonal climate.
units and description
description and units of data in csv files
plantation characteristics
Characteristics of plantations; First column is an identifier, second column is the plantation number and third column is the plot replicate in the plantation. Fourth and fifth columns are the latitude and longitude of the plot site, sixth column is the management type, seventh column is the annual rainfall, eight and ninth columns are the age and altitude of the plantation, tenth and eleventh columns are the coffee age and coffee plants per hectare, the last column is the slope. The data has been collected in February-May 2013.
Shade tree characteristics
Characteristics of shade trees; First column is an identifier, second column is the plantation number and third column is the plot replicate in the plantation. Fourth column is the number of trees per hectare, fifth and sixth columns are the stand basal area and mean basal area of the trees, seventh column is the percentage of Grevillea robusta trees per plot, column eight is the Shannon's diversity index per plot, ninth column is the canopy cover at coffee harvest (December). The data has been collected in February 2013 to December 2014.
soil characteristics
Characteristics of the soil; First column is an identifier, second column is the plantation number and third column is the plot replicate in the plantation. Fourth column is the density of the soil, columns five to eight are the soil contents of gravel, clay, silt and sand, ninth column is the soil pH, tenth column is the cation exchange capacity, eleventh and twelveth columns are the total soil carbon and mineral N concentrations in the soil, columns thirteen to last are the plant available concentrations of P, K, Ca, Mg, S, Fe, Mn, Zn, and B. The data has been collected in December 2014.
Shade tree and coffee litter mass and nutrients inputs
Litter fall and nutrient inputs; First column is an identifier, second column is the plantation number and third column is the plot replicate in the plantation. Fourth,fifth, sixth and seventh columns are the yearly inputs per hectare of total litter, coffee leaf litter, shade tree leaf litter (excluding Grevillea robusta leaf litter) and Grevillea robusta leaf litter. The columns eight to eighteen are the yearly nutrient inputs per hectare through coffee litter, the columns nineteen to twenty nine are the yearly nutrient inputs per hectare through shade tree leaf litter. The data has been collected in between June 2013 to December 2014.
Shade tree and coffee litter mass decomposition and nutrient contents
not decomposed leaf litter mass and nutrient contents after 153 days; First column is an identifier, second column is the plantation number and third column is the plot replicate in the plantation. Fourth, fifth, sixth and seventh columns are the not decomposed residues of the standard, coffee leaf litter, shade tree leaf litter, mix of shade tree and coffee leaf litter. Columns eight to eightteen are the nutrient contents in the not decomposed coffee litter residues, Columns nineteen to twenty-nine are the nutrient contents in the not decomposed shade tree leaf litter residues. Columns thirty to forty are the nutrient contents in the not decomposed mixture of shade tree and coffee leaf litter residues.The data has been collected in November 2014.
