Soluble reactive phosphorus (SRP) transport and retention in tropical, rain forest streams draining a volcanic landscape in Costa Rica: in situ SRP amendment to streams and laboratory studies

2006 ◽  
Vol 81 (2) ◽  
pp. 145-157 ◽  
Author(s):  
Frank Triska ◽  
Catherine M. Pringle ◽  
John H. Duff ◽  
Ronald J. Avanzino ◽  
Gary Zellweger
Keyword(s):  
Costa Rica ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Soluble Reactive Phosphorus ◽  
Laboratory Studies ◽  
Reactive Phosphorus ◽  
Forest Streams

Shrimp abundance and habitat relationships in tropical rain-forest streams, Sarawak, Borneo

2003 ◽  
Vol 19 (4) ◽  
pp. 387-395 ◽  
Author(s):  
Tomoya Iwata ◽  
Mikio Inoue ◽  
Shigeru Nakano ◽  
Hitoshi Miyasaka ◽  
Atsushi Doi ◽  
...  
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Secondary Forest ◽  
High Water ◽  
Water Velocity ◽  
Primary Forest ◽  
Microhabitat Use ◽  
Secondary Forests ◽  
Habitat Differences ◽  
Forest Streams

Microhabitat use and habitat-abundance relationships of four freshwater shrimps, Atyopsis moluccensis, Macrobrachium pilimanus, Macrobrachium trompii and Macrobrachium neglectum, were surveyed in tropical streams running through primary and secondary forests in Borneo, East Malaysia. Underwater observations revealed that A. moluccensis preferred relatively high water velocity and a boulder substrate. Macrobrachium pilimanus also preferred high water velocity and a cobble substrate, whereas M. trompii occupied stream margins with slow current and fine substrates (from POM (particulate organic matter) to pebbles). In contrast, M. neglectum was distributed relatively evenly through the stream channel. The abundance of A. moluccensis, M. pilimanus and M. trompii in the stream reaches was best explained by the abundance of boulders, cobbles and POM, respectively, suggesting that the amount of preferred microhabitat is an important factor affecting shrimp abundances in the tropical rain-forest streams. The primary-forest reaches were dominated by coarse substrates, such as cobbles and boulders, while a great proportion of the streambeds in the secondary-forest reaches were covered with sand. Owing probably to such habitat differences, the abundance of both A. moluccensis and M. pilimanus, which preferred coarse substrates, was less in the secondary- than in the primary-forest reaches. These suggested that loss of preferred habitat, namely decreased coarse substrate availability, by sedimentation resulting from riparian deforestation had altered the shrimp assemblage structures.

VOLUME 19, NUMBER 4, JULY 2003 Shrimp abundance and habitat relationships in tropical rain-forest streams, Sarawak, Borneo

2003 ◽  
Vol 19 (05) ◽  
pp. 606 ◽  
Author(s):  
Tomoya Iwata ◽  
Mikio Inoue ◽  
Shigeru Nakano ◽  
Hitoshi Miyasaka ◽  
Atsushi Doi ◽  
...  
Keyword(s):  
Rain Forest ◽  
Tropical Rain Forest ◽  
Forest Streams ◽  
Shrimp Abundance

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

1984 ◽  
Vol 72 (2) ◽  
pp. 553 ◽  
Author(s):  
Robin L. Chazdon ◽  
Ned Fetcher
Keyword(s):  
Costa Rica ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Lowland Tropical Rain Forest

scholarly journals Strumigenys fairchildi Brown, 1961 (Formicidae, Myrmicinae): first record of this rarely collected ant from Brazil

Check List ◽  
2016 ◽  
Vol 12 (4) ◽  
pp. 1922 ◽  
Author(s):  
Lívia P. Prado ◽  
Ricardo Eduardo Vicente ◽  
Thiago S. R. Silva ◽  
Jorge L. P. Souza
Keyword(s):  
Costa Rica ◽  
High Resolution ◽  
Biodiversity Conservation ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
First Record ◽  
Distribution Map ◽  
Mato Grosso ◽  
High Resolution Images ◽  
First Time

Strumigenys fairchildi Brown, 1961 is recorded for the first time in Brazil. This ant species was previously known only from a few specimens collected in Costa Rica, Panama and Ecuador. The worker S. fairchildi was collected at the Parque Estadual do Cristalino, a continuous area of Amazon tropical rain forest protected for biodiversity conservation in the municipality of Novo Mundo, Mato Grosso state. In addition, we present a distribution map and high-resolution images of the worker.

Hypolimnetic Aeration: An Overview

1986 ◽  
Vol 21 (2) ◽  
pp. 205-217 ◽  
Author(s):  
D.J. McQueen ◽  
D.R.S. Lean
Keyword(s):  
Ammonia Volatilization ◽  
Cold Water ◽  
Soluble Reactive Phosphorus ◽  
Eutrophic Lakes ◽  
Hypolimnetic Oxygen ◽  
Dissolved Hydrogen ◽  
Phosphorus Sedimentation ◽  
Reactive Phosphorus ◽  
Maximum Removal

Abstract Hypolimnetic aerators are now being widely used throughout Europe and are beginning to appear in small and medium sized eutrophic lakes in temperate North America. This activity has produced approximately 42 published reports dealing with experiments conducted at 16 lakes. Taken together, the evidence from these experiments suggests that well designed aerators do not cause significant destratification or warming of hypolimnetic water, but do result in measurable Increases in hypolimnetic oxygen concentration and decreases in dissolved hydrogen sulfide, methane and ammonia. Early experiments suggested that phosphorus sedimentation was unpredictable, but recent work has demonstrated that when the ratio of total iron to soluble reactive phosphorus exceeds 10:1 and pH is < 7.5, phosphorus sedimentation is assured and internal loading greatly reduced. Early experiments also showed that ammonia volatilization was unpredictable, but at pH > 8.0, ammonia volatilization will occur. Because both phosphorus sedimentation and nitrogen reduction are pH dependent, both cannot be optimally removed during the same period of time and so the experimenter is advised to select for the maximum removal of one or the other through pH manipulation. Hypolimnetic aeration induces oxygen consumption and this must be considered when choosing an appropriate compressor size. Most studies show little impact on phytoplankton blomass, but one recent experiment showed that aeration during spring turnover resulted in reduced concentrations of chlorophyll a and TP. Zooplankton populations are, for the most part, unaffected and a number of American studies have shown that hypolimnetically aerated lakes can support cold water fish populations. The aggregate practical and experimental experience suggests that well designed hypolimnetic aeration systems yield measurable improvements in water quality and will almost certainly prove to be one of the major methods used for future in situ lake restoration.

Assessment of sediment and porewater after one year of subaqueous capping of contaminated sediments in Hamilton Harbour, Canada

1998 ◽  
Vol 37 (6-7) ◽  
pp. 323-329 ◽  
Author(s):  
José M. Azcue ◽  
Alex J. Zeman ◽  
Alena Mudroch ◽  
Fernando Rosa ◽  
Tim Patterson
Keyword(s):  
Soluble Reactive Phosphorus ◽  
Coarse Sand ◽  
Contaminated Sediments ◽  
Overlying Water ◽  
Hamilton Harbour ◽  
Vertical Fluxes ◽  
Reactive Phosphorus ◽  
One Year ◽  
In Situ Capping

In this manuscript, we present data from a demonstration in situ capping site (100 m × 100 m) in Hamilton Harbour, Lake Ontario, Canada. A layer of clean medium to coarse sand with the average thickness of 35 cm was placed at the site in the summer of 1995. Concentration of Zn, Cr, and Cd in the original sediments reached values over 6000, 300 and 15 μg/g, respectively. The predicted consolidation of the uppermost one meter of sediment was about 14 cm, which was in good agreement with values obtained from comparisons of moisture content values of pre-capping and post-capping cores. A thin layer of fresh moderately contaminated sediments has started to develop on the top of the cap. In general, the concentrations of elements were greater in porewater than in the overlying water, e.g., the concentration of Fe and soluble reactive phosphorus were 1000 times, and those of Mn 100 times greater. There was a significant reduction in the vertical fluxes of all the trace elements after the capping of the contaminated sediments.

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