Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Decayed woodrat middens increase soil resources and accelerate the decompostion of contemporary litter at Yucca baccata patches

Auteur : Campos, Herman

Université de soutenance : New Mexico State University

Grade : Master of Science (MS) 2017

Notes
Ecosystem engineers can significantly alter biogeochemical processes in an environment. I studied effects of woodrat (Neotoma spp.) middens on the soil-litter environment and decomposition of litter within Yucca baccata patches in the Chihuahuan desert. I specifically focused on how the activity state of the midden affects these processes. Each Yucca patch contained no midden, an active or a decayed midden. Soil was collected at each patch type an analyzed for soil organic carbon (SOC), total nitrogen (N), available nitrogen (NH⁴⁺, NO³⁻) and moisture. To evaluate litter decomposition at each patch, I calculated mass loss rates using a 12-moth litter bag experiment utilizing foliar mesquite (Proposis glandulosa) or poplar wood (Populus spp.) litter. Soil organic carbon, N, available nitrogen and the decay rates of mesquite litter were all significantly faster in patches that contain a decayed midden. At active middens, soil nutrients and litter decay rates were no different than at Yucca patches without middens. My study found that the biogeochemical changes caused by ecosystem engineers, in this case woodrats, can be dynamic and dependent on the state of the engineered structure and that the effect could persist long-term, beyond the life of the engineer.

Présentation (NMSU Library)