Community attributes determine facilitation potential in a semi-arid steppe

Abstract

Please cite this article as: Amat, B., Cortina, J., Zubcoff, J.J.,Community attributes determine facilitation potential in a semi-arid steppe., Perspectives in Plant Ecology, Evolution and Systematics (2014), http://dx.doi.org/10.1016/j.ppees. 2014.10.001 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. interactions. Conversely, the interaction with other co-occurring species has scarcely been addressed, despite the fact that the entire community may affect plant performance. We used woody vegetation patches as models to evaluate community facilitation in semi-arid steppes. 5We characterized biotic and physical attributes of 53 woody patches (patch size, litter accumulation, canopy density, vegetation cover, species number and identity, and phylogenetic distance), and soil fertility (organic C and total N), and evaluated their relative importance for the performance of seedlings of Pistacia lentiscus, a keystone woody species in western Mediterranean steppes. Seedlings were planted underneath the patches, and on 10 their northern and southern edges. Woody patches positively affected seedling survival but not seedling growth. Soil fertility was higher underneath the patches than elsewhere. Physical and biotic attributes of woody patches affected seedling survival, but these effects depended on microsite conditions. The composition of the community of small shrubs and perennial grasses growing underneath the patches controlled seedling performance. An increase in Stipa 15 tenacissima and a decrease in Brachypodium retusum increased the probability of survival.The cover of these species and other small shrubs, litter depth and community phylogenetic distance, were also related to seedling survival. Seedlings planted on the northern edge of the patches were mostly affected by attributes of the biotic community. These traits were of lesser importance in seedlings planted underneath and in the southern edge of patches, suggesting 20 that constraints to seedling establishment differed within the patches. Our study highlights the importance of taking into consideration community attributes over pair-wise interactions when evaluating the outcome of ecological interactions in multi-specific communities, as they

The balance of canopy and soil effects determines intraspecific differences in foundation species’ effects on associated plants

“…Foundation species ameliorate climatic conditions or maintain resource levels above that of bare ground habitats, and their effects are often species-specific (Macek, Prieto, Macková, Pistón, & Pugnaire, 2016;Proffitt, Chiasson, Owens, Edwards, & Travis, 2005). The different microhabitats created by different co-occurring foundation species can then be colonized by distinct sets of subordinate species, resulting in higher community-level diversity (Amat, Cortina, & Zubcoff, 2015;Chen et al, 2015;Pistón et al, 2016).…”

The use of branch piles to assist in the restoration of degraded semiarid steppes

“…Verdú and García‐Fayos () observed that trees act as perches for birds in abandoned crops in the southeastern Iberian Peninsula, and promoted nucleation via seed establishment beneath the perches. Likely, if birds continued to use branch piles long term at our site, persistent seed rain could foster seedling establishment in semiarid steppes where chances of spontaneous colonization are low (Amat et al ).…”

Stress‐gradient hypothesis and plant distribution along ecotonal gradients

“…), attenuated thermal stress, insolation (Malkinson & Tielbörger ) and runoff water (Amat et al . ), increased infiltration (Pugnaire et al . ; Cecchi et al .…”

“…; Amat et al . ; Tirado et al . ), there have been some exceptions (Bertness & Ewanchuk ; López et al .…”

“…Extremely high temperatures, overgrazing, as well as the low nutrient concentration (Amat et al . ) and, above all, water scarcity (Noy‐Meir ; Fernández ) make arid environments sites of high stress. Since arid systems are threatened by desertification (Millennium Ecosystem Assessment ), a deep understanding of their functioning is of particular importance for a better implementation of environmental mitigation and restoration practices.…”