Scientific question:
In forests, understory vegetation and aboveground litter from plants are indispensable to ecosystem stability and ecological function. Understory vegetation and aboveground litterfall play vital roles in maintaining above- and below-ground biota and biodiversity, microclimates, soil erosion, and ecosystem nutrient cycling. The loss of species and functional groups caused by human activities has been widely concerned. However, few studies have been conducted to evaluate the consequences of understory or litter removal on forest ecosystems, and the results obtained are far from sufficient to allow a complete understanding.
Objective:
The main objectives are to (i) quantify the impacts of understory and litter removal on carbon and nitrogen cycle; and (ii) assess the interaction between the removals of both understory vegetation and aboveground litter r on the structure and function of forest ecosystem.
Experimental design:
The experiment was established in September 2015 using a randomized complete block design with four replicates per treatment (one block for each replicate). The study contained a complete factorial combination of litter removal (L) and understory removal (U), which produced four treatments: control (C), L, U, and LU, thus resulting in a total of 16 plots. The area of each plot was 100 m2 (10 m × 10 m), with a 5–m–wide buffer zone between adjacent plots to eliminate the edge effect. Each month, litterfall on the forest floor was removed manually raking in the L and LU plots. The native understory vegetation and germinating understory plants were removed monthly by hand from the U and LU plots with the help of a machete knife. The forest floor was not undisturbed in all plots throughout this study.