caa a22 4500 445384026 CHVBK 20180317143026.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s10021-011-9486-y doi (NATIONALLICENCE)springer-10.1007/s10021-011-9486-y Mechanisms of Araucaria (Atlantic) Forest Expansion into Southern Brazilian Grasslands [Elektronische Daten] [Lucas Silva, Madhur Anand] Recent studies have shown that tropical and subtropical forests expanded during the late Holocene, but rates and mechanisms of expansion are still unknown. Here, we investigate how a forest-grassland mosaic changed over the past 10,000years at the southernmost limit of the Brazilian Atlantic forest. We used soil organic matter carbon isotopes (δ13C and 14C) to quantify and date changes in vegetation, examining soil properties and leaf traits of tree species (nutrient content, δ13C, δ15N, and specific leaf area—SLA) to describe potential mechanisms of expansion. Our results show that after several millennia of stability, forests have been expanding over grasslands through continuous, but very slow, border dynamics and patch formation (<100m since ~4,000 YBP). This process of expansion coincided withpastchanges in climate, but biotic feedback mechanisms also appear to be important for the long-term persistence and expansion of forests. Soil fertility and microbial biomass match current rather than past vegetation distribution, increasing progressively across the gradient: grasslands<isolated trees<forest patches<forests. Foliar δ15N values of trees that are able to colonize the grassland are consistently lower across this vegetation gradient, suggesting an increasingly greater reliance on symbiotic nutrient uptake from grasslands to forests. No significant relationships were found between soil and leaf nutrients, but SLA explained variation in leaf N, P, and K (positive relationships) and in leaf δ13C (negative relationship). These findings suggest thatatradeoff between tree growth and water use efficiencyis animportant regulator of forest-grassland dynamics in the study region. Springer Science+Business Media, LLC, 2011 ecotone nationallicence forest nationallicence grassland nationallicence microbial biomass nationallicence nutrients nationallicence soil-plant feedbacks nationallicence stable isotopes nationallicence Silva Lucas School of Environmental Sciences, Global Ecological Change Laboratory, University of Guelph, N1G 2W1, Guelph, Ontario, Canada aut Anand Madhur School of Environmental Sciences, Global Ecological Change Laboratory, University of Guelph, N1G 2W1, Guelph, Ontario, Canada aut Ecosystems Springer-Verlag 14/8(2011-12-01), 1354-1371 1432-9840 14:8<1354 2011 14 10021 https://doi.org/10.1007/s10021-011-9486-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10021-011-9486-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Silva Lucas School of Environmental Sciences, Global Ecological Change Laboratory, University of Guelph, N1G 2W1, Guelph, Ontario, Canada aut NATIONALLICENCE 700 1- Anand Madhur School of Environmental Sciences, Global Ecological Change Laboratory, University of Guelph, N1G 2W1, Guelph, Ontario, Canada aut NATIONALLICENCE 773 0- Ecosystems Springer-Verlag 14/8(2011-12-01), 1354-1371 1432-9840 14:8<1354 2011 14 10021 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer