Presence of understory shrubs constrains carbon gain in sunflecks by advance-regeneration seedlings: evidence from quercus rubra seedlings growing in understory forest patches with or without evergreen shrubs present
Abstract
We investigated whether dynamic photosynthesis of understory Quercus rubra L. (Fagaceae) seedlings can acclimate to the altered pattern of sunflecks in forest patches with Rhododendron maximum L. (Ericaceae), an understory evergreen shrub. Maximum photosynthesis (A) and total CO(2) accumulated during lightflecks was greatest for 400-s lightflecks, intermediate for 150-s lightflecks, and lowest for 50- and 75-s lightflecks. For the 400-s lightflecks only, maximum A and total CO(2) accumulated were significantly lower for seedlings in forest patches with shrubs present (SF) than for seedlings in forest patches without shrubs (F). These effects were found only when A was calculated on a leaf-area basis because the specific leaf area of seedlings in F patches was 16% lower than it was for seedlings in SF patches. Photosynthesis reached 50% induction in 159 s for seedlings in F patches compared with 226 s for seedlings in SF patches. The faster induction of A for seedlings in F patches resulted in a significantly higher lightfleck use efficiency than for seedlings in SF patches. The inefficient use of lightflecks by Q. rubra seedlings in SF patches may be a primary mechanism by which Q. rubra seedlings are inhibited by subcanopy thickets of R. maximum.
Collections
Related items
Showing items related by title, author, creator and subject.
-
Implementing the proposals for action of the intergovernmental panel on forests and the intergovernmental forum on forests: A tool to assist national-level assessment of progress and priorities for action toward sustainable forest management, developed in support of the United Nations Forum on Forests
Australia. Department of Agriculture, Fisheries and Forestry; World Bank. Program on Forests (PROFOR) (2003-05)The Intergovernmental Panel on Forests (IPF)/ Intergovernmental Forum on Forests (IFF) proposals for action that are summarized in this document focus on country-level action to be undertaken by national and sub-national ... -
Women's participation in national forest programmes: Formulation, execution and revision of national forest programmes
Food and Agriculture Organization of the United Nations. United Nations Development Programme (Rome, Italy: FAO Formulation, Execution and Revision of National Forest Programme, 1997)This document emphasizes the importance of being gender inclusive to increase the possibility for success with forest development programs. By focusing on men and women's differences and complementarities, this document ... -
Students can walk through forest online with award-winning 4-H Virtual Forest
Johnson, Mary Ann (Virginia Tech. University Relations, 2005-05-31)Elementary and middle school students can take advantage of an award-winning hi-tech way to learn about forestry using the 4-H Virtual Forest from Virginia Cooperative Extension.