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Temperature‐induced recruitment pulses of Arctic dwarf shrub communities
Author(s) -
Büntgen Ulf,
Hellmann Lena,
Tegel Willy,
Normand Signe,
MyersSmith Isla,
Kirdyanov Alexander V.,
Nievergelt Daniel,
Schweingruber Fritz H.
Publication year - 2015
Publication title -
journal of ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.452
H-Index - 181
eISSN - 1365-2745
pISSN - 0022-0477
DOI - 10.1111/1365-2745.12361
Subject(s) - tundra , shrub , ecology , arctic , plant community , climate change , arctic vegetation , vegetation (pathology) , ecosystem , context (archaeology) , population , phenology , growing season , geography , environmental science , ecological succession , biology , demography , medicine , archaeology , pathology , sociology
Summary The effects of climate change on Arctic ecosystems can range between various spatiotemporal scales and may include shifts in population distribution, community composition, plant phenology, primary productivity and species biodiversity. The growth rates and age structure of tundra vegetation as well as its response to temperature variation, however, remain poorly understood because high‐resolution data are limited in space and time. Anatomical and morphological stem characteristics were recorded to assess the growth behaviour and age structure of 871 dwarf shrubs from 10 species at 30 sites in coastal East Greenland at ˜70°N. Recruitment pulses were linked with changes in mean annual and summer temperature back to the 19th century, and a literature review was conducted to place our findings in a pan‐Arctic context. Low cambial activity translates into estimated average/maximum plant ages of 59/204 years, suggesting relatively small turnover rates and stable community composition. Decade‐long changes in the recruitment intensity were found to lag temperature variability by 2 and 6 years during warmer and colder periods, respectively ( r = 0.85 1961–2000 and 1881–1920 ). Synthesis . Our results reveal a strong temperature dependency of Arctic dwarf shrub reproduction, a high vulnerability of circumpolar tundra ecosystems to climatic changes, and the ability of evaluating historical vegetation dynamics well beyond the northern treeline. The combined wood anatomical and plant ecological approach, considering insights from micro‐sections to community assemblages, indicates that model predictions of rapid tundra expansion (i.e. shrub growth) following intense warming might underestimate plant longevity and persistence but overestimate the sensitivity and reaction time of Arctic vegetation.