Abstract:

Abstract:

Abstract:

Abstract:

Long term series of weekly total of incident pricipitation (mean of 5 replicates), pH and EC of bulked PCP samples.
NOTE: PCP volumes from > April 2003 need to be quality checked (rate 50 to 20). 

Taken from Fleischbein et al. (2005):
Rainfall interception in forests is influenced by properties of the canopy that tend to vary over small distances. Our objectives were: (i) to determine the variables needed to model the interception loss of the canopy of a lower montane forest in south Ecuador, i.e. the storage capacity of the leaves S and of the trunks and branches S-t, and the fractions of direct throughfall p and stemflow p(t); (ii) to assess the influence of canopy density and epiphyte coverage of trees on the interception of rainfall and subsequent evaporation losses.
The study site was located on the eastern slope of the eastern cordillera in the south Ecuadorian Andes at 1900-2000 m above sea level. We monitored incident rainfall, throughfall, and stemflow between April 1998 and April 2001. In 2001, the leaf area index (LAI), inferred from light transmission, and epiphyte coverage was determined.

The mean annual incident rainfall at three gauging stations ranged between 2319 and 2561 mm. The mean annual interception loss at five study transects in the forest varied between 591 and 1321 mm, i.e. between 25 and 52% of the incident rainfall. Mean S was estimated at 1(.)91 mm for relatively dry weeks with a regression model and at 2(.)46 mm for all weeks with the analytical Gash model; the respective estimates of mean S-t were 0(.)04 mm and 0(.)09 mm, of mean p were 0(.)42 and 0(.)63, and of mean pt were 0(.)003 and 0(.)012. The LAI ranged from 5(.)19 to 9(.)32. Epiphytes, mostly bryophytes, covered up to 80% of the trunk and branch surfaces. The fraction of direct throughfall p and the LAI correlated significantly with interception loss (Pearson's correlation coefficient r = -0(.)77 and 0(.)35 respectively, n = 40). Bryophyte and lichen coverage tended to decrease S, and vascular epiphytes tended to increase it, although there was no significant correlation between epiphyte coverage and interception loss. Our results demonstrate that canopy density influences interception loss but only explains part of the total variation in interception loss. Copyright (c) 2004 John Wiley & Sons, Ltd.

Abstract:

Taken from Boy (2008):
Successful conservation of tropical montane forest, one of the most threatened
ecosystems on earth, requires detailed knowledge of its biogeochemistry. Of particular
interest is the response of the biogeochemical element cycles to external influences such
as element deposition or climate change. Therefore the overall objective of my study
was to contribute to improved understanding of role and functioning of the Andean
tropical montane forest. In detail, my objectives were to determine (1) the role of long-
range transported aerosols and their transport mechanisms, and (2) the role of short-term
extreme climatic events for the element budget of Andean tropical forest.
     In a whole-catchment approach including three 8-13 ha microcatchments under
tropical montane forest on the east-exposed slope of the eastern cordillera in the south
Ecuadorian Andes at 1850-2200 m above sea level I monitored at least in weekly
resolution the concentrations and fluxes of Ca, Mg, Na, K, NO3-N, NH4-N, DON, P, S,
TOC, Mn, and Al in bulk deposition, throughfall, litter leachate, soil solution at the 0.15
and 0.3 m depths, and runoff between May 1998 and April 2003. I also used
meteorological data from my study area collected by cooperating researchers and the
Brazilian meteorological service (INPE), as well as remote sensing products of the
North American and European space agencies NASA and ESA.
    My results show that (1) there was a strong interannual variation in deposition of Ca
[4.4-29 kg ha-1 a-1], Mg [1.6-12], and K [9.8-30]) between 1998 and 2003. High
deposition changed the Ca and Mg budgets of the catchments from loss to retention,
suggesting that the additionally available Ca and Mg was used by the ecosystem.
Increased base metal deposition was related to dust outbursts of the Sahara and an
Amazonian precipitation pattern with trans-regional dry spells allowing for dust
transport to the Andes. The increased base metal deposition coincided with a strong La
Niña event in 1999/2000. There were also significantly elevated H+, N, and Mn
depositions during the annual biomass burning period in the Amazon basin. Elevated H+
deposition during the biomass burning period caused elevated base metal loss from the
canopy and the organic horizon and deteriorated already low base metal supply of the
vegetation. Nitrogen was only retained during biomass burning but not during non-fire
conditions when deposition was much smaller. Therefore biomass burning-related
aerosol emissions in Amazonia seem large enough to substantially increase element
deposition at the western rim of Amazonia. Particularly the related increase of acid
deposition impoverishes already base-metal scarce ecosystems. As biomass burning is
most intense during El Niño situations, a shortened ENSO cycle because of global
warming likely enhances the acid deposition at my study forest.
    (2) Storm events causing near-surface water flow through C- and nutrient-rich
topsoil during rainstorms were the major export pathway for C, N, Al, and Mn
(contributing >50% to the total export of these elements). Near-surface flow also
accounted for one third of total base metal export. This demonstrates that storm-event
related near-surface flow markedly affects the cycling of many nutrients in steep
tropical montane forests. Changes in the rainfall regime possibly associated with global
climate change will therefore also change element export from the study forest.
    Element budgets of Andean tropical montane rain forest proved to be markedly
affected by long-range transport of Saharan dust, biomass burning-related aerosols, or
strong rainfalls during storm events. Thus, increased acid and nutrient deposition and
the global climate change probably drive the tropical montane forest to another state
with unknown consequences for its functions and biological diversity.

Abstract:

From Boy et al. 2008:
Abstract: 
We explored the influence of biomass burning in Amazonia and northeastern Latin America on N, C, P, S, K, Ca, Mg, Al, Mn, and Zn cycles of an Andean montane forest in south Ecuador exposed to the Amazon basin between May 1998 and April 2003. We assessed the response of the element budget of three microcatchments (8 - 13 ha) to the variations in atmospheric deposition between the intensive burning season and outside the burning season in Amazonia. There were significantly elevated H, N, and Mn depositions during biomass burning. Elevated H deposition during biomass burning caused elevated base metal loss from the canopy and the organic horizon and deteriorated already low base metal supply of the vegetation. N was only retained during biomass burning but not during nonfire conditions when deposition was much smaller. We conclude that biomass burning-related aerosol emissions in Amazonia are large enough to substantially increase element deposition at the western rim of Amazonia. Particularly the related increase of acid deposition impoverishes already base metal scarce ecosystems. As biomass burning is most intense during El Nino situations, a shortened El Nino - Southern Oscillation cycle because of global warming likely enhances the acid deposition at our study forest.

Abstract:

From Boy et al. 2008:
Abstract: 
We explored the influence of biomass burning in Amazonia and northeastern Latin America on N, C, P, S, K, Ca, Mg, Al, Mn, and Zn cycles of an Andean montane forest in south Ecuador exposed to the Amazon basin between May 1998 and April 2003. We assessed the response of the element budget of three microcatchments (8 - 13 ha) to the variations in atmospheric deposition between the intensive burning season and outside the burning season in Amazonia. There were significantly elevated H, N, and Mn depositions during biomass burning. Elevated H deposition during biomass burning caused elevated base metal loss from the canopy and the organic horizon and deteriorated already low base metal supply of the vegetation. N was only retained during biomass burning but not during nonfire conditions when deposition was much smaller. We conclude that biomass burning-related aerosol emissions in Amazonia are large enough to substantially increase element deposition at the western rim of Amazonia. Particularly the related increase of acid deposition impoverishes already base metal scarce ecosystems. As biomass burning is most intense during El Nino situations, a shortened El Nino - Southern Oscillation cycle because of global warming likely enhances the acid deposition at our study forest.

Abstract:

Climate data measured by automatic Thies weather station of the working group B2.

Abstract:

manual measurement of fog & precipitation; (1 m²-mesh-collector at 1 m above ground)

Abstract:

manual measurement of fog & precipitation; (1 m²-mesh-collector at 1 m above ground)