Litter chemistry and abiotic effects on plant recruitment success in denuded areas of Patagonian Monte rangelands

BERTILLER, MÓNICA BEATRIZ; BOSCO, TOMÁS; SARAVÍ CISNEROS, HEBE; CARRERA, ANALÍA LORENA

Foz do Iguassu

Conferencia; VII World Conference on Ecological Restoration V Congreso Iberoamericano y del Caribe de Restauración Ecológica I Conferência Brasileira de Restauração Ecológica; 2017

SER; SOBRE, SIACRE

Litter chemistry and abiotic effects on plant recruitment success in denudedareas of Patagonian Monte rangelands.Grazing disturbance reduced the cover of preferred species and increase soil gaps in aridecosystems. Litter amendment is a managerial tool usually used for soil and plant restorationin denuded areas of these ecosystems. We evaluated the effect of litter chemistry (C/N ratio)combined with different levels of UV radiation exposure and soil water on soil inorganic-N(SN in ) and recruitment of two dominant perennial grasses (Poa ligularis and Nassella tenuis)and an evergreen shrub (Atriplex lampa) preferred by herbivores and a dominant evergreenshrub (Larrea divaricata) non preferred and with chemical defenses against herbivores indenuded areas of the Patagonian Monte. Microcosms with soil of denuded areas were sowedwith seeds of all species in separated cells subjected during 6 months to the combined effectsof litter cover (without litter (NL), litter with C/N ratio =15 and C/N ratio =48), UV radiation(near ambient (Am-UV) and reduced (Re-UV)), and volumetric soil water (high (15-25%HSW) and low (5-15% (LSW)). We assessed SN in, concentration periodically and speciesrecruitment (probability transition from seed to established plant) at the end of theexperiment. Low C/N ratio in litter and Am-UV increased SN in . Soil water enhanced SN in onlyat one date. Perennial grass species and A. lampa recruitment was increased with augmentedSN in . None factor affected the recruitment of L. divaricata. We concluded that litteramendment combined with exposure to UV radiation throughout the effect on soil inorganicN may modulate plant recruitment success of species preferred by herbivores in denudedareas.