Temporal variation of phytoplankton in a small tropical crater lake, Costa Rica

 

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Bibliographic Details
Author: Umaña-Villalobos, Gerardo
Format: artículo
Status:Versión publicada
Publication Date:2010
Description:The temporal variation in lake's phytoplankton is important to understand its general biodiversity. For tropical lakes, it has been hypothesized that they follow a similar pattern as temperate ones, on a much accelerated pace; nevertheless, few case studies have tried to elucidate this. Most studies in Costa Rica have used a monthly sampling scheme and failed in showing the expected changes. In this study, the phytoplankton of the small Barvas’s crater lake was followed for more than three years, first with monthly and later with weekly samplings, that covered almost two years. Additional information on temperature and oxygen vertical profiles was obtained on a monthly basis, and surface temperature was measured during weekly samplings around noon. Results showed that in spite of its shallow condition (max. depth: 7m) and low surface temperature (11 to 19°C), the lake stratifies at least for brief periods. The phytoplankton showed both, rapid change periods, and prolonged ones of relative stasis. The plankton composition fluctuated between three main phases, one characterized by the abundance of small sized desmids (Staurastrum paradoxum, Cosmarium asphaerosporum), a second phase dominated by equally small cryptomonads (Chryptochrysis minor, Chroomonas sp.) and a third phase dominated by the green alga Eutetramorus tetrasporus. Although data evidenced that monthly sampling could miss short term events, the temporal variation did not follow the typical dry and rainy seasons of the region, or any particular annual pattern. Year to year variation was high. As this small lake is located at the summit of Barva Volcano and receives the influence from both the Caribbean and the Pacific weather, seasonality at the lake is not clearly defined as in the rest of the country and short term variations in the local weather might have a stronger effect than broad seasonal trends. The occurrence of this short term changes in the phytoplankton of small tropical lakes in response to weather variations needs to be further explored in other lakes.
Country:Portal de Revistas UCR
Institution:Universidad de Costa Rica
Repositorio:Portal de Revistas UCR
Language:Inglés
OAI Identifier:oai:portal.ucr.ac.cr:article/5420
Online Access:https://revistas.ucr.ac.cr/index.php/rbt/article/view/5420
Access Level:acceso abierto
Keyword:biodiversidad del fitoplancton
lagos tropicales
lagos cratéricos
variación temporal
dinámica de comunidades
Phytoplankton biodiversity
tropical lake
crater lake
temporal variation
community dynamics