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Ecological consequences of variation in precipitation: separating short‐ versus long‐term effects using satellite data
Author(s) -
Jin Yufang,
Goulden Michael L.
Publication year - 2014
Publication title -
global ecology and biogeography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.164
H-Index - 152
eISSN - 1466-8238
pISSN - 1466-822X
DOI - 10.1111/geb.12135
Subject(s) - precipitation , environmental science , ecosystem , disturbance (geology) , photosynthetically active radiation , arid , atmospheric sciences , phenology , vegetation (pathology) , climatology , climate change , spatial variability , term (time) , ecology , geography , meteorology , biology , geology , medicine , paleontology , statistics , photosynthesis , botany , mathematics , physics , pathology , quantum mechanics
Aim Precipitation controls the production of semi‐arid plants through various mechanisms that operate at a range of time‐scales. Short‐term variation in precipitation affects vegetation through adjustments in plant physiology and leaf phenology, whereas long‐term effects are mediated by plant establishment and mortality, community composition and disturbance regimes. Our goal is to use remote sensing observations to separate the short‐ and long‐term effects of variation in precipitation on ecosystem production. Location C alifornia, USA.Methods We used time series of gridded absorbed photosynthetically active radiation ( APAR ) to quantify the short‐ and long‐term responses of diverse ecosystems to variation in precipitation across large productivity and precipitation gradients. We investigated the relationships between temporal sensitivity of APAR to interannual variation in precipitation and mean annual precipitation ( MAP ), ecosystem properties and disturbance. Results APAR increased with precipitation both interannually within locations and across locations with MAP . The slope of the interannual relationship, which reflects the sensitivity of APAR to short‐term fluctuations in precipitation, varied with climate, vegetation type and structure, and time since disturbance. The interannual APAR sensitivity decreased from c . 0.5 MJ m −2 mm −1 at a MAP of 300 mm year −1 to less than 0.05 MJ m −2 mm −1 at 1000 mm year −1 . The slope of the spatial relationship, which reflects the long‐term sensitivity of APAR to climate, decreased from c . 2.5 MJ m −2 mm −1 at 300 mm year −1 MAP to c . 0.6 MJ m −2 mm −1 at 1000 mm year −1 . The initial physiological and leaf area effects of a precipitation shift were amplified five‐fold over time by gradual changes in population density and species composition. Main conclusion The impact of a hydroclimatic shift on the primary production, structure and function of C alifornia's terrestrial ecosystems depends heavily on time‐scale and how rapidly changes in plant population density and community composition can occur.