Decomposition of Eucalyptus grandis and Acacia mangium leaves and fine roots in tropical conditions did not meet the Home Field Advantage hypothesis

Abstract

a b s t r a c tUnlike Eucalyptus monocultures, nitrogen fixing trees are likely to improve the soil nutrient status through the decomposition of N-enriched litter. The Home Field Advantage (HFA) hypothesis states that plants can create conditions that increase the decomposition rates of their own litter. However, there may not be any HFA when most of the decomposers are generalists. A reciprocal transplant decomposition experiment of fine roots and leaves of Acacia mangium and Eucalyptus grandis was undertaken in monocultures of these two species to test the HFA hypothesis using a complete randomized design with three blocks. Three litterbags containing leaf or fine root residues of each species were collected every 3 months from each plot over 12 months for fine roots and 24 months for leaves. The litter mass and C, N and P concentrations were measured at each sampling date. The concentrations of C-compounds were measured 0, 12 and 24 months from the start of the experiment. There was no evidence of HFA for either the leaves or the fine roots of either species. The decomposition rates were slower for Acacia litter than for Eucalyptus litter even though initial N concentrations were 1.9-2.9 times higher and P concentrations were 1.5-3.3 times higher in the Acacia residues. N:P ratios were greater than 20-30 for the residues of both species, with the highest values for Acacia. Litter decomposition depended partly on the C quality of the litter, primarily in terms of water soluble compounds and lignin content. As shown recently in tropical rainforests, these results suggest that the activity of decomposers is limited by energy starvation in tropical planted forests. Decomposer activity may also have been limited by P availability which may not have been directly related to the P concentrations or C:P ratios in the residues.

Decomposition rates of forest residues and soil fertility after clear‐cutting of Eucalyptus grandis stands in response to site management and fertilizer application

“…In general, increasing proportions of forest residue relatively rich in easily accessible C compounds (nonstructural carbohydrates, phenolics – energy‐rich C compounds) and relatively poor in recalcitrant C (condensed tannins, lignin, polyphenols) present the best correlation with litter mass loss (Northup et al ., ; Hättenschwiler & Jørgensen, ; Bachega et al ., ). The decomposition decay rate, k, of the forest residue fractions followed the order: leaves > bark > branches.…”

Necrobiome framework for bridging decomposition ecology of autotrophically and heterotrophically derived organic matter

“…Such a phenomenon has been found when examining the interaction between climate and microbial communities , Averill et al 2016. Although HFA has been observed across a variety of different soil decomposer communities (Ayres et al 2009), it has been found absent in others (St John et al 2011, Bachega et al 2016. One explanation for this divergence is HFA only accounts for adaptation to a particular organic matter resource and does not account for the fact that some decomposer microbial communities simply decompose an array of necromass types more rapidly due to greater functional breadth (Keiser et al 2014).…”

“…, Bachega et al. ). One explanation for this divergence is HFA only accounts for adaptation to a particular organic matter resource and does not account for the fact that some decomposer microbial communities simply decompose an array of necromass types more rapidly due to greater functional breadth (Keiser et al.…”

Litterfall, litter layer and leaf decomposition in Eucalyptus stands on Cerrado soils

“…The percentage of remaining biomass in the litter bags still not decomposed was similar to that found in an E. urophylla plantation in the state of Bahia, in which Pinto et al (2016) verified rates of 73.56% at 180 days after the beginning of the experiment. In the state of São Paulo, Bachega et al (2016) at 180 days after experiment initiation, it was 63.00% of the leaf biomass remaining in the litter bags in an E. grandis planting. This pattern of recalcitrance seems to be characteristic of eucalypt leaves and may be mainly due to the high levels of lignin and polyphenols present.…”