N Deposition Affects N Availability in Interstitial Water, Growth of Sphagnum and Invasion of Vascular Plants in Bog Vegetation

• Published in: The New phytologist Vol. 157; no. 2; pp. 339 - 347
• Main Authors: Limpens, Juul, Berendse, Frank, Klees, Herman
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science 01.02.2003; Blackwell Science Ltd; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; application rate; Betula; Betula pubescens; Biological and medical sciences; Biomass; Bogs; Demecology; deposition; Fundamental and applied biological sciences. Psychology; global change; Growing seasons; height; Inflorescences; light; Molinia; Molinia caerulea; mortality; Netherlands; Nitrogen; nitrogen content; plant characteristics; plant competition; Plant growth; Plants; Plants and fungi; raised bogs; rhizosphere; Seedlings; Sphagnum; Sphagnum magellanicum; sprouting; Vascular plants; Vegetation; water; water chemistry; water table; Netherlands; Monocotyledones; Growth; Bogs; Available nutrient; Biomass; Inorganic element; Sphagnobrya; Interstitial water; Sphagnum; Gramineae; Dicotyledones; Angiospermae; Interspecific competition; Hardwood forest tree; Chemical concentration; Small tree; Betulaceae; Water chemistry; Atmospheric fallout; Betula pubescens; deposition; Bryophyta; Phosphorus; Molinia; Vegetation dynamics; Nitrogen; Invasion; raised bogs; Rhizosphere; global change; Nutrient; Spermatophyta; Betula; nitrogen; water chemistry
• ISSN: 0028-646X; 1469-8137; 1469-8137
• DOI: 10.1046/j.1469-8137.2003.00667.x

• We studied the effects of N deposition on shrub-moss competition and the establishment and growth of invasive Betula pubescens and Molinia caerulea in intact bog vegetation removed from a site subject to 40 kg N ha-1yr-1. • Mesocosms with and without introduced Betula seedlings and Molinia sprouts were kept under a roof and received an equivalent of 0, 40 and 80 kg N ha-1yr-1for two growing seasons. • N concentration in both interstitial water and Sphagnum decreased when N input ceased and increased when N input was doubled. Molinia biomass was positively related to the inorganic N concentration in the interstitial water. Adding N increased production of Molinia and prolonged survival of Betula seedlings in the first year. Sphagnum height increment showed a hump-shaped relationship with light interception by vascular plants. • N deposition encouraged vascular plants to grow by enhancing N availability in the rhizosphere. Water table level and the availability of P were found to be important in explaining species-specific responses to N deposition. The underlying mechanisms and the reversibility of N effects are discussed.