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A meta‐analysis of mycorrhizal responses to nitrogen, phosphorus, and atmospheric CO 2 in field studies
Author(s) -
Treseder Kathleen K.
Publication year - 2004
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2004.01159.x
Subject(s) - nutrient , phosphorus , human fertilization , ecosystem , fertilizer , agronomy , field experiment , biology , symbiosis , nitrogen , biome , ecology , chemistry , organic chemistry , genetics , bacteria
Summary• Numerous field studies have measured mycorrhizal dynamics under additions of nitrogen (N), phosphorus (P), or atmospheric CO 2 to test the hypothesis that plants should invest in mycorrhizal fungi when soil nutrients are limiting. • Here meta‐analyses were used to integrate nutrient responses across independent field‐based studies. Responses were compared between ecto‐ and arbuscular mycorrhizal fungi, and among fertilizer types, methods of measurement, biomes, and lead investigators. Relationships between degree of response and study length, fertilization rates, total amounts of nutrients applied, and numbers of replicates were also tested. • Across studies, mycorrhizal abundance decreased 15% under N fertilization and 32% under P fertilization. Elevated CO 2 elicited a 47% increase. Nitrogen effects varied significantly among studies, and P effects varied significantly among lead investigators. Most other factors did not affect mycorrhizal responses. • These results support the plant investment hypothesis, and suggest that global standing stocks of mycorrhizal fungi may increase substantially under elevated CO 2 but decline moderately under P additions. Effects of N deposition may be difficult to predict for individual ecosystems, with a slightly negative influence overall.