Light Environment in Tropical Rain Forest of Central Amazonia

Brinkmann, W. L. F.

doi:10.1590/1809-43921971012037

Cited by 8 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While data on photosynthesis and growth are lacking for most rain forest species (Mooney et al 1980), detailed descriptions of characteristic forest light environments will provide a much needed framework for future studies on the ecophysiology and dynamics of rain forest vegetation. Several important descriptions of the distribution of light in tropical rain forests throughout the world have been published (Evans 1939;Ashton 1958;Whitmore & Wong 1959;Odum, Drewry & Kline 1970;Brinkman 1971;Bjorkman & Ludlow 1972;Yoda 1974). Virtually no data are available which allow comparisons between characteristic environments within the same forest type (Schulz 1960;Bazzaz & Pickett 1980).…”

Section: Introductionmentioning

confidence: 99%

Photosynthetic Light Environments in a Lowland Tropical Rain Forest in Costa Rica

Chazdon¹,

Fetcher²

1984

The Journal of Ecology

596

379

View full text Add to dashboard Cite

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Ecology. SUMMARY(1) Measurements of photosynthetic photon flux density (PPFD) in four sites within a lowland tropical rain forest were compared. The habitats investigated were a 0.5 ha clearing, a 400 m2 gap, a 200 m2 gap, and heavily shaded understorey.(2) Measurements were made during both wet and dry seasons under a variety of weather conditions. Quantum sensors were used to monitor continuously 10-min average PPFD over a 3-10 day period at each location. Daily average PPFD, total daily PPFD, and daily frequency distributions were analysed for two adjacent sensors per site on each sampling day.(3) Daily total PPFD in the understorey, 200 m2 gap, and 400 m2 gap were 1-2%, 9%, and 20-35%, respectively, of PPFD in the clearing. Daily total PPFD in the 400 m2 gap during the dry season was, on average, 2.4 times greater than in the 200 m2 gap, and 20-25 times those in the understorey. In the 200 m2 gap, daily total PPFD was nine times greater than in the understorey during the dry season.(4) In the clearing, PPFD was significantly different between seasons with 24% higher PPFD during the dry season. In the 400 m2 gap and understorey, PPFD was not significantly different between seasons.(5) The percentage of available PPFD reaching the understorey was highest on cloudy, overcast days and lowest on sunny days. No correlation was found between daily total PPFD in the 400 m2 gap centre and in the adjacent understorey measured on the same days.(6) In the clearing, a high proportion of 10-min averages were greater than 500 ,umol m-2 s-I; in the 400 m2 gap, a high proportion of 10-min averages were between 100,umol m-2 s-1 and 500 umol m-2 s-1; in the understorey over 70% of the 10-min averages were below 10,urmol m-2 s-1. The clearing exhibited the greatest diurnal variation in PPFD and the least day-to-day variation, whereas the understorey exhibited the least diurnal variation and the greatest day-to-day variation in PPFD.

show abstract

Section: Introductionmentioning

confidence: 99%

Photosynthetic Light Environments in a Lowland Tropical Rain Forest in Costa Rica

Chazdon¹,

Fetcher²

1984

The Journal of Ecology

596

379

View full text Add to dashboard Cite

show abstract

“…Light is one of the most important environmental factors for maintaining the survival and growth of tropical forests, as it is the source of energy for photosynthesis. Tropical forest structure and light are closely linked (Brinkmann, 1971; Fotis et al., 2018). The dense, closed canopy of tropical forests intercepts more light than the canopy of more open forests, increasing forest productivity (Clark et al., 2013; Duarte et al., 2021; Guan et al., 2015; Morin, 2015).…”

Section: Tropical Forests and Supporting Servicesmentioning

confidence: 99%

“…The establishment of new species in the community can figure as an important factor in forest resilience to disturbances, such as, for example, landslides in forested areas that abruptly change the soil cover condition. Thus, through the control of light incidence, tropical forests control several processes fundamental for their own maintenance and survival (Brinkmann, 1971; Fotis et al., 2018) and, consequently, for ESs provisioning.…”

Section: Tropical Forests and Supporting Servicesmentioning

confidence: 99%

Beyond Carbon: The Contributions of South American Tropical Humid and Subhumid Forests to Ecosystem Services

Borma

Costa

Rocha

et al. 2022

Reviews of Geophysics

View full text Add to dashboard Cite

Tropical forests are key habitats for diverse organisms, and because of their wide global distribution, rich biodiversity, and long history of human use, they are also essential for providing a wide range of ecosystem services (ESs;Brandon, 2015; Brockerhoff et al., 2017;Gibson et al., 2011;Mori et al., 2017). Considerable attention has been devoted to tropical forests and their role as a natural climate solution for mitigating climate change. It is estimated that about 30% of all CO 2 emitted by human activities is removed from the atmosphere by these forests (Le Quéré et al., 2018). The important role of tropical forests as a carbon sink and stock has historically guided conservation pacts, programs, and policies for establishing targets associated with carbon storage and climate change mitigation. This role was important in developing several articles of the 1997 Kyoto Protocol (Swingland et al., 2002) and explicit policies for reducing emissions from deforestation and forest degradation through the REDD+ agreement (Pistorius, 2012). Several countries also set ambitious goals for restoring forests to reduce emissions or sequester carbon in the United Nations Framework Convention on Climate Change 2015 Paris Agreement. The land use, land cover change, and forestry (LULCCF) sector is included in many countries' first nationally determined contributions (NDCs) but with differing levels of specificity. Assuming full implementation of NDCs, Grassi et al. (2017) show that land use-and forests, in particular-emerges as a key component of the Paris Agreement: global land use will turn from a net anthropogenic source during 1990-2010 (1.3 ± 1.1 Gt CO 2 e yr −1 ) to a net sink of carbon by 2030 (up to −1.1 ± 0.5 Gt CO 2 e yr −1 ) and would provide a quarter of countries' planned emission reductions. Two tropical countries stand out regarding the magnitude of the LULCCF contribution: Brazil set ambitious goals of reducing greenhouse gas emissions by 43% by 2030 with

show abstract

“…Tropical rainforests have dense vegetation, often forming three different layers including a dense canopy that blocks out ca. 95% of sunlight (Brinkmann, 1971; Bourgeron, 1983; Chazdon and Fetcher, 1984; Vazquez-Yanes et al ., 1990). Therefore, the rainforest ground rarely receives direct sunlight.…”

Section: Introductionmentioning

confidence: 99%

Coccidial oocyst release: once a day or all day long? Tropical bird hosts shed new light on the adaptive significance of diurnal periodicity in parasite output

et al. 2021

View full text Add to dashboard Cite

Many parasites spend part of their life cycle as infectious forms released from an infected host in the external environment, where they may encounter and infect new hosts. The emergence of infectious life stages often occurs once a day to minimize mortality in adverse environments. In bird hosts, intestinal parasites such as coccidia are generally released with feces in the late afternoon. This dynamic is adaptive since it allows avoiding desiccation and ultraviolet (UV) radiation, thus reducing mortality of oocysts in the environment until transmission to the next host. If this circadian rhythm is the result of natural selection to increase oocyst survival, we may hypothesize that oocysts will appear in feces at different times depending on the environment where hosts live. Particularly, in an environment where UV radiation and desiccation are very low, we may expect oocyst circadian release to disappear since the main selective pressure would be relaxed. We sampled different species of birds in tropical and temperate forests in spring and investigated coccidian oocyst output. A strong circadian variation in the prevalence of hosts shedding coccidian oocyst was detected for species caught in the temperate forest with an increase in prevalence in the late afternoon, whereas prevalence of birds shedding oocysts was constant over the course of the day for most species sampled in the tropical rain forest. These results are consistent with the hypothesis that oocysts’ circadian output is maintained by natural selection to increase oocyst survival. We discuss the adaptive significance of diurnal periodicity in parasite output.

show abstract

Light Environment in Tropical Rain Forest of Central Amazonia

Cited by 8 publications

References 0 publications

Photosynthetic Light Environments in a Lowland Tropical Rain Forest in Costa Rica

Photosynthetic Light Environments in a Lowland Tropical Rain Forest in Costa Rica

Beyond Carbon: The Contributions of South American Tropical Humid and Subhumid Forests to Ecosystem Services

Coccidial oocyst release: once a day or all day long? Tropical bird hosts shed new light on the adaptive significance of diurnal periodicity in parasite output

Contact Info

Product

Resources

About