Title of article :
Expansion of Calamagrostis villosa in sub-alpine Nardus stricta grassland: Cessation of cutting management or high nitrogen deposition?
Author/Authors :
Michal Hejcman، نويسنده , , Michaela Klaudisov?، نويسنده , , Pavla Hejcmanov?، نويسنده , , Vilém Pavl?، نويسنده , , Martina Jones، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
Abstract :
Calamagrostis villosa has recently expanded in Nardus stricta-dominated sub-alpine grassland of the Giant Mountains (Krkonoše/Karkonosze, the Czech Republic). To investigate whether this expansion has been promoted by high nitrogen deposition or by the cessation of agricultural management, grassland plots dominated by C. villosa were manipulated with four treatments: control (Con), fertilised (Fer), cut (Cut) and cut–fertilised (Cut–Fer). NH4NO3 was used at the rate of 30 kg N ha−1 and fertilisation and cutting were performed once a year after data collection in late July between 2000 and 2006.
Plant species composition (analysed by RDA) was significantly influenced by cutting but not by fertilisation. Cutting reduced the cover, biomass, sward height and tiller density of C. villosa. Seedlings of N. stricta and panicles of C. villosa were recorded only in plots with cutting management.
To investigate the effect of treatments on the spread of C. villosa, grassland sods dominated by N. stricta were transplanted into the experimental plots. Six years later, the density and cover of C. villosa spreading into the N. stricta sods were highest in Fer treatment.
C. villosa was recognised as a defoliation-sensitive species and this sensitivity cannot be overcome by an increase in N supply. Recent expansion of C. villosa in the sub-alpine grassland can by explained by a long-term succession after the cessation of agricultural management and an increase in the N availability in recent decades.
Keywords :
Long-term N fertiliser experiment , Defoliation sensitivity , Tiller density , Krkono?e/Karkonosze , Flowering induction
Journal title :
Agriculture Ecosystems and Environment
Journal title :
Agriculture Ecosystems and Environment