Temporal variation and frequency distribution of photosynthetic photon fluxdensities on landslides in Puerto Rico

TitleTemporal variation and frequency distribution of photosynthetic photon fluxdensities on landslides in Puerto Rico
Publication TypeJournal Article
Year of Publication1995
AuthorsFernandez, E, Myster, RW
JournalTropical Ecology
Volume36
Pagination73-87
Accession NumberLUQ.156
Keywordsrainforest
Abstract

We examined the light environment and its daily variation, both between landslides in different watersheds (the Espiritu Santo watershed contains landslide ES2 and the Rio Blanco watershed contains RB2) and within each landslide on different microhabitats, in the Luquillo Mountaines of Puerto Rico. We found that availability of photosynthetic photon flux density (PFD) peaked in the morning hours on ES2, and that differences between sunny and cloudy days were greater on ES2 than on RB2. For both landslides: (1) these trends were magnitude compared to pen microhabitats (2) forest PFD was reduced by two orders of magnitude compared to open microhabitats and (3) there were reduced PFD levels and heterogeneity with distance from the top of the landslide. In addition, ES2 had more variation in total daily PFD than RB2 and sites on the western side of ES2 received up to 10 times more light than the eastern sites. Usually, low PFD ( lt 100 mu-mol m-2 s-1) was more common than high ( gt 400 mu-mol m-2 s-1) except in the top transect where there was a mix of frequencies and a substantial number of high values.

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