Long-term addition of fertilizer, labile carbon, and fungicide alters the biomass of plant functional groups in a subarctic-alpine community

TY - JOUR

T1 - Long-term addition of fertilizer, labile carbon, and fungicide alters the biomass of plant functional groups in a subarctic-alpine community

AU - Haugwitz-Hardenberg-Reventlow, M S

AU - Michelsen, A.

PY - 2011/4

Y1 - 2011/4

N2 - In subarctic ecosystems, plant growth is mostly limited by nutrient availability and harsh climate. Investigating how soil nutrient availability controls the plant community composition may therefore help to understand indirect effects of climate change. The study was conducted in a long-term field experiment on a subarctic-alpine fellfield dominated by woody evergreen shrubs, bryophytes, and lichens. To manipulate nutrient availability additions of NPK fertilizer, labile C, and fungicide (benomyl) were done in a fully factorial design, replicated in six blocks. The treatments were run for 10 years, and the aboveground plant biomass was harvested 4 and 16 years after initiating the experiment. In addition, soil inorganic N and P concentration was analyzed the same years. Increased nutrient availability (NPK fertilizer) largely increased the biomass of graminoids and unexpectedly of bryophytes, but not of other vascular plant groups. Also, limitation of soil nutrient availability caused by labile C addition decreased the relative proportion of green shoots in evergreen shrubs, although these were expected to cope better with the nutrient limitation than the opportunistic graminoids, which, by contrast, were unaffected. Reduced fungal biomass due to benomyl addition was accompanied by increased evergreen shrub and clubmoss biomass. Taken together, the effects of treatments were most pronounced 16 years after initiation of the experiment, but despite changes in biomass the overall plant community composition was resistant to environmental changes.

AB - In subarctic ecosystems, plant growth is mostly limited by nutrient availability and harsh climate. Investigating how soil nutrient availability controls the plant community composition may therefore help to understand indirect effects of climate change. The study was conducted in a long-term field experiment on a subarctic-alpine fellfield dominated by woody evergreen shrubs, bryophytes, and lichens. To manipulate nutrient availability additions of NPK fertilizer, labile C, and fungicide (benomyl) were done in a fully factorial design, replicated in six blocks. The treatments were run for 10 years, and the aboveground plant biomass was harvested 4 and 16 years after initiating the experiment. In addition, soil inorganic N and P concentration was analyzed the same years. Increased nutrient availability (NPK fertilizer) largely increased the biomass of graminoids and unexpectedly of bryophytes, but not of other vascular plant groups. Also, limitation of soil nutrient availability caused by labile C addition decreased the relative proportion of green shoots in evergreen shrubs, although these were expected to cope better with the nutrient limitation than the opportunistic graminoids, which, by contrast, were unaffected. Reduced fungal biomass due to benomyl addition was accompanied by increased evergreen shrub and clubmoss biomass. Taken together, the effects of treatments were most pronounced 16 years after initiation of the experiment, but despite changes in biomass the overall plant community composition was resistant to environmental changes.

KW - Benomyl

KW - Bryophytes

KW - Fellfield

KW - Lichens

KW - Nutrient availability

KW - Plant biomass

KW - SIMULATED ENVIRONMENTAL-CHANGE

KW - NUTRIENT APPLICATION

KW - MICROBE COMPETITION

KW - FACTORIAL ADDITION

KW - NPK FERTILIZER

KW - DWARF SHRUBS

KW - AMINO-ACIDS

KW - RESPONSES

KW - TUNDRA

KW - SOIL

U2 - 10.1007/s11258-010-9857-z

DO - 10.1007/s11258-010-9857-z

M3 - Journal article

SN - 1385-0237

VL - 212

SP - 715

EP - 726

JO - Plant Ecology

JF - Plant Ecology

IS - 4

ER -