Response variable Ecological meaning Sampling period Simplified description
Plant Community Height It is often correlated with leaf quality, longevity, and life-history traits. It is often used as a proxy of plant biomass (Guimarães-Steinicke et al., 2019). 31/Mar to 13/Sep 2021 Using a terrestrial laser scanner (TLS), we generated 3D point clouds of the plot center. The 3D point clouds were classified into soil and vegetation points, to further extract average plant community height (Guimarães-Steinicke et al., 2019).
Plant Greenness It can be related to vegetation density, chlorophyll content, and photosynthetic activity and is normally used to detect leaf greening up and autumn coloring timing. (Motohka et al., 2010; Cleland et al., 2006). 31/Mar to 13/Sep 2021 We installed one phenological camera (Brinno TLC200) pointing to the center of each plot corner. For each picture, we calculated the Green-Red Vegetation Index (GRVI) (Motohka et al., 2010; Yin et al., 2022).
Root Production It is often related to soil carbon content, cycle, and capacity to acquire water and nutrients. It usually correlates to net primary productivity and soil fauna activity (Ravenek et al., 2014; McCormack et al., 2014). 10/Mar/2021 to 03/Feb/2022 We scanned each plot using minirhizotrons. We then identified the root pixels of each scan using a Neural Network and calculated the number of root pixels per scan (Ma & Chen 2016; Ravenek et al., 2014).
Detritivore Feeding Activity Bait consumption is used as a proxy of detritivores’ feeding activity and is correlated with root exudation, decomposition rates, and nutrient mineralization. 26/Feb/2021 to 03/Feb/2022 In-situ decomposer feeding activity was measured using bait lamina strips, which are PVC sticks with 16 holes filled with cellulose-based bait. In each sampling period, old laminas were removed from the soil. The holes were rated as empty (all bait material was consumed, indicating high feeding activity), partly empty, or filled. Then, new laminas were inserted in the soil (Birkhofer et al., 2011; Eisenhauer et al., 2014).