The influence of non-nitrogenous nutrient additions on growth and physiology of sugar maple and composition of understory vegetation in northern hardwoods of central Ontario.
Published: 2006
Language: eng
Number of pages: 190
ISBN-13: 9780494218594
Description: While it is widely assumed that most temperate forests are nitrogen limited, many stands located in areas affected by high N deposition exhibit signs of nitrogen excess. Symptoms include an increase in nitrate concentration and a decrease in the C:N ratio of both soil and foliage; thus affected ecosystems are expected to experience a significant reduction in their natural nitrogen limitation. This process is likely accompanied by changes in availability of phosphorus and basic cations. This work demonstrates that N-induced deficiency of P, K, Ca and Mg is evident in sugar maple dominated northern hardwoods of central Ontario. Research presented here also examines several interrelated aspects of forest responses to additions of non-N mineral nutrients, including their effects on forest floor and mineral soil, diameter increment of trees, canopy physiology and morphology, and diversity of understory vegetation. This thesis demonstrates that the addition of truly growth-limiting nutrients does increase tree growth even among slow-growing, tolerant species such as sugar maple. Furthermore, growth increase is evident among mature and young trees within a relatively short time if monitoring of tree canopy response is included in research. This work also shows that while liming and non-N nutrient additions help alleviate many negative effects of nitrate pollution, they also escalate the process of forest eutrophication, which influences diversity of understory vegetation.
Notes: Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0014.

Thesis (Ph.D.)--University of Toronto, 2006.

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