Litter Decomposition in Wet Rubber and Fruit Agroforests: Below the Threshold for Tropical Peat Formation

Abstract

Peatlands are shaped by slow litter decomposition, but threshold decomposition rates that allow peat formation remain unclear. Can agroforestry in the tropics be compatible with paludiculture that allows peat formation? We explored the determinants of litter decomposition in wet agroforests adjacent to tropical peatlands in Central Kalimantan (Indonesia) by litterbag studies (up to 16 weeks) with standing litter sources to estimate rate constants, characterize litter quality (especially lignin (L), polyphenolics (Pp) and nitrogen (N)), and monitor temperature and groundwater levels. In litter transfer experiments we tested for home-field advantage (HFA) effects between land cover types. Mean residence times around 85 weeks at 27 °C were associated with a high (L + Pp)/N ratio. However, in the crossover treatments, mean residence times varied from 30 to 180 weeks and strong HFA effects (up to 80% faster decomposition at “home”) were found when litter from other sources was tested in old fruit-based agroforests. HFA indicates a local decomposer community well-adapted to its normal litter diet. Litter residence times of around two years are below the apparent peat formation threshold. Maintaining wet agroforest conditions adjacent to peat domes supports peatland rewetting and restoration but does not contribute to on-site peat formation processes.

Performance assessment Of Indian Spinach (Basella alba) as an Under Storey Crop in Aonla-Lemon Based Multistoried Agroforestry System Manuscript Draft

“…For instance, to grow Aonla fruit, no additional input (water and fertilizer) was applied but yielded better than sole aonla plantation as well as middle-storied lemon also yielded better with no additional inputs [46]. Trees in crop fields have some advantages on crop productivity such as continuous deposition of mulch and nutrient-enriching topsoil [47]. Additional resources from trees such as fruits, firewood, timber and non-timber also add to the income table.…”

Home‐field advantage in litter decomposition: A critical review from a microbial perspective

“…Hu et al [10] used ADH to verify the litter Phosphorus content and the contribution of soil fauna in different environments to the HFA. Silvianingsih et al [51] calculated ADH and found that the decomposition rate caused by the HFA was 80% faster.…”

Soil Degradation Due to Conversion from Natural to Plantation Forests in Indonesia

“…Measurements in an A. crassicarpa plantation on organic soils (also known as peatlands) showed slow litter decomposition due to a high lignin content (36%-39%), low P and N content (P < 0.25% and N < 2.5%), and unfavourable soil environment, microclimate conditions [144], and a poor soil microbe population [145]. In (agro)forests on the fringe of a peat dome, wet conditions slowed decomposition, but not enough to induce peat formation [146].…”