Plant removal experiments are recognized as effective methods to understand plant species’ ecosystem functions under vegetation change scenarios. To minimize disturbance to the soil, the most prominent method for plant removal is to cut off aboveground parts of plants repeatedly and leave roots remain in the soil. However, how the remaining roots affect soil organisms still needs to be explored.

Researchers led by Prof. ZUO Juan from Wuhan Botanical Garden set up 1 mm root mesh bags in a three-year Plant functional group (PFG) removal experiment in a Qinghai-Tibet alpine meadow with five PFG treatments: no-removal control, Legumes (remove forbs and graminoids), Forbs (remove legumes and graminoids), Graminoids (remove legumes and forbs) and All-plant-removed. Target plants’ roots (partially as root litter) existed only outside the mesh bags. After one year, soil nematodes were identified inside and outside of the root mesh bags.

The results showed that except for the no-removal control treatment, the structure of nematode communities inside and outside of mesh bags was generally differentiated, indicated by non-metric multidimensional scaling. Nematode communities outside the mesh bags had higher nematode channel ratio and lower channel index values, indicating that root litter outside the mesh bags increased energy flux to bacterial-feeding nematodes over fungal-feeding nematodes. The relative abundance of plant-feeding nematode increased inside compared to outside the mesh bags, probably because of a higher ratio of living roots inside the mesh bags.

This study indicates that cutting off plant aboveground parts and leaving plant roots remain in the soil have a legacy effect on the soil nematode community structure.

Results entitled “Impact of remaining roots on soil nematode communities in an aboveground plant functional group removal experiment” have been published on Plant and Soil.

Conceptual figure of the effects of PFG removal and root mesh bags on soil nematode communities (Image by WBG)