Effets à long-terme du chaulage sur le sol et la végétation des pâturages subalpines

Le résumé fourni par la source

Theoretical advances and short-term experimental studies have furthered our\nunderstanding of how ecosystems respond to perturbation. However, there are few wellreplicated experimental studies that allow an assessment of long-term responses. Results from a controlled, large-scale field experiment in a subalpine grassland near Interlaken, Switzerland, show that 2-4 years of liming (Ca: 40 gm2yr1) still significantly affected the composition of the vegetation and the soil microbial community nearly 70 years after the treatments were\nimposed, whereas NPK fertilization (8 gm2yr1) only marginally affected vegetation\ncomposition. The exchangeable content of Ca ions and soil pH were higher in limed plots but\nwere unaffected in fertilized plots. Plant species and PLFAs (phospholipid fatty acids)\nindicating low pH values were found in higher abundance in the unlimed plots, suggesting that\nthe long-lasting effects of liming on the above- and belowground communities were mediated\nthrough changes in soil pH. The results of this long-term study indicate that the resilience of\nmountain ecosystems may be particularly low in response to perturbations that substantially\nalter soil pH or other key determinants of belowground processes.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.