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2485245 
Journal Article 
Effects of fertilisation and irrigation on 'foliar afterlife' in alpine tundra 
Soudzilovskaia, NA; Onipchenko, VG; Cornelissen, JHC; Aerts, R 
2007 
Journal of Vegetation Science
ISSN: 1100-9233
EISSN: 1990-2002 
18 
755-766 
Question: How do increases in soil nutrient and water availability alter the nutrient fluxes through the resorption and litter decomposition pathways and how do they affect litter nutrient pools in a low-productive alpine tundra ecosystem?



Location: An alpine lichen-rich tundra on Mt. Malaya Khatipara in the NW Caucasus, Russia (43 degrees 27' N, 41 degrees 42' E; altitude 2800 m a. s. l.).



Methods: We conducted a 4-year fertilisation (N, P, N+ P, lime) and irrigation experiment, and analysed the responses of nutrient resorption from senescing leaves, leaf litter quality and decomposability of six pre-dominant vascular plant species, total plant community litter production and litter (nutrient) accumulation.



Results: Vascular plant litter [N] and [P] increased 1.5 and 10 fold in response to N and P additions, due to increased concentrations of the nutrients in fresh leaves and unchanged or reduced resorption efficiency. Litter decomposability was not affected by nutrient amendments. Fertilisation enhanced litter production (180%; N+ P treatment) and litter accumulation (80%; N+ P), owing to tremendously increased production and low decomposability of graminoids. Together with increased litter [ N] and [P] this led to great increases in total litter nutrient pools.



Conclusions: Due to increased production of graminoids, nutrients added to the alpine tundra soil were mostly immobilised in recalcitrant, nutrient- rich litter. This suggests that changing species composition in low productive ecosystems may act as an internal buffer mechanism, which under increased soil nutrient availability prevents the community from rapidly acquiring features typical of a high productive ecosystem such as high decomposability and high nutrient availability. 
alpine ecosystem; forb; graminoid; litter production; litter decomposition; litter quality; mineralisation; nutrient addition; plant growth form; resorption