Publications
Found 505 publication(s)
- of type article
Windhorst, D.; Waltz, T.; Timbe, E.; Frede, H. & Breuer, L. (2013): Impact of elevation and weather patterns on the isotopic composition of precipitation in a tropical montane rainforest. Hydrol. Earth Syst. Sci. 177, 409-419.
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DOI: 10.5194/hess-17-409-2013
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Abstract:
Abstract:
This study presents the spatial and temporal variability of ?18O and ?2H isotope signatures in precipitation of a south Ecuadorian montane cloud forest catchment (San Francisco catchment). From 2 September to 25 December 2010, event sampling of open rainfall was conducted along an altitudinal transect (1800 to 2800 m a.s.l.) to investigate possible effects of altitude and weather conditions on the isotope signature.
The spatial variability is mainly affected by the altitude effect. The event based ?18O altitude effect for the study area averages ?0.22‰ × 100 m?1 (?2H: ?1.12‰ × 100 m?1). The temporal variability is mostly controlled by prevailing air masses. Precipitation during the times of prevailing southeasterly trade winds is significantly enriched in heavy isotopes compared to precipitation during other weather conditions. In the study area, weather during austral winter is commonly controlled by southeasterly trade winds. Since the Amazon Basin contributes large amounts of recycled moisture to these air masses, trade wind-related precipitation is enriched in heavy isotopes. We used deuterium excess to further evaluate the contribution of recycled moisture to precipitation. Analogously to the ?18O and ?2H values, deuterium excess is significantly higher in trade wind-related precipitation. Consequently, it is assumed that evaporated moisture is responsible for high concentrations of heavy isotopes during austral winter.
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Keywords: |
climate |
rainwater chemistry |
hydrological processes |
isotopes |
Setaro, S.; Garnica, S.; Herrera, P. & Goeker, M. (2011): A clustering optimization strategy to estimate species richness of Sebacinales in the tropical Andes based on molecular sequences from distinct DNA regions. Biodiversity and Conservation 21, 2269-2285.
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DOI: 10.1007/s10531-011-0205-y
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Abstract:
Abstract:
Fungi are believed to be diverse in the tropics, but because many groups are
only known from their DNA sequences this hampers comparative diversity studies. We
investigated mycorrhizal Sebacinales (Basidiomycota) of 67 individuals of Ericaceae and
Orchidaceae in a tropical mountain ecosystem in Southern Ecuador to provide a ?rst
estimate of whether these fungi are particularly diverse in the Northern Andes. We par-
tially sequenced the internal transcribed spacer (ITS) and large subunit (LSU) regions of
the nuclear ribosomal DNA and analyzed them together with all Sebacinales sequences
available from GenBank. The clustering optimization technique was used to determine
clustering parameters that maximize the comparability between molecular operational
taxonomic units (MOTUs) obtained from the distinct loci. Sampling effort and species
richness were estimated with rarefaction-accumulation curves and non-parametric esti-
mation using Chao2 and compared between Southern Ecuador and France. Clustering
optimization indicated that a 1% LSU distance threshold corresponds to the commonly
used 3% dissimilarity threshold for ITS, and that a clustering algorithm close to single-
linkage clustering is optimal. The resulting clusters show that about 8?9% of observed Sebacinales MOTUs occur in the study area and that most of these MOTUs are endemic
(74%). The widespread MOTUs from Southern Ecuador were also found in Panama, North
America and Europe. The estimation of species richness revealed unsaturated sampling of
Sebacinales in general and also in our study area. Our results suggest a high diversity of
Sebacinales associated with Ericaceae and Orchidaceae at the study site in Southern
Ecuador, but no hotspot of Sebacinales in comparison with other areas.
Homeier, J.; Hertel, D.; Camenzind, T.; Cumbicus Torres, N.; Maraun, M.; Martinson, G.; Poma, N.; Rillig, M.C.; Sandmann, D.; Scheu, S.; Veldkamp, E.; Wilcke, W.; Wullaert, H. & Leuschner, C. (2012): Tropical Andean Forests Are Highly Susceptible to Nutrient Inputs - Rapid Effects of Experimental N and P Addition to an Ecuadorian Montane Forest. PLoS ONE 7, e47128.
Potthast, K.; Hamer, U. & Makeschin, F. (2012): In an Ecuadorian pasture soil the growth of Setaria sphacelata, but not of soil microorganisms, is co-limited by N and P. Applied Soil Ecology 62, 103-114.
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DOI: 10.1016/j.apsoil.2012.08.003
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Abstract:
Abstract:
In the mountain rainforest region of southern Ecuador, soils of active pastures, established after slashand-
burn of the forest, are characterized by improved quantity and quality of soil organic matter favoring
microbial conditions. However, these beneficial conditions decrease with increasing pasture age and
burning frequency. As a consequence, rates of soil nutrient cycling decrease, supporting the infestation
of bracken fern and, in turn, causing further decreases in pasture productivity. Finally, farmers are forced
to abandon the degraded pastures and to establish new ones by continuous deforestation. To investigate
whether an application of N and/or P nutrients to an extensively grazed pasture (active pasture) can
improve grass productivity and maintain soil fertility, a pasture fertilization experiment was conducted.
On an active pasture site, planted with Setaria sphacelata, moderate rates of urea (50 kg N ha−1 a−1), rock
phosphate (10 kg P ha−1 a−1), and a combination of both were applied. It was examined whether soil
mineralization (gross and net N mineralization, SOC mineralization) and microbial community structure
(PLFA-analysis), as well as quantity and quality of the grass biomass, were affected by fertilization.
Furthermore, the impact of fertilization on in situ soil respiration rates was studied. The combined application
of urea and rock phosphate increased the pasture yield by 2 Mg ha−1 a−1 most efficiently, indicating
a co-limitation of growth. Additionally, the fodder quality was improved by a 67% higher content of P
and by a 7% higher content of Ca in the grass biomass compared to the control. While carbon, nitrogen,
and phosphorus in the microbial biomass remained unaffected and the microbial activity increased
only temporarily, the relative abundance of fungi (18:2n6,9) increased significantly due to fertilizer addition.
Urea addition induced a short-lived increase in the in situ soil CO2-C effluxes, assuming a positive
priming effect due to an activation of soil microbes. In total, plots amended with urea emitted 0.8 Mg CO2-
C ha−1 a−1 more than the control. Results reveal that already moderate fertilization significantly improved
pasture productivity and maintained soil quality. However, it is expected that higher loads of NP fertilizer
will increase pasture productivity at the expense of soil organic carbon sequestration due to enhanced
soil CO2-C losses. Hence, to establish a sustainable pasture management in the study region, the soil C
management must also be carefully considered.
Thies, B.; Meyer, H.; Nauss, T. & Bendix, J. (2012): Projecting land use and land cover changes in a tropical mountain forest of southern Ecuador. Journal of Land Use Science xx, 1-33.
Behling, H. & Schüler, L. (2010): Characteristics of Poaceae pollen grains as a tool to assess palaeoecological grassland dynamics in South America. Vegetation History and Archaeobotany 20, 97-108.
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DOI: 10.1007/s00334-010-0264-0
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Abstract:
Abstract:
During the Quaternary, in particular during
glacial times, different grassland ecosystems played a
much larger role and had a significantly larger distribution.
Little is known yet about past development, biodiversity
and dynamics of grassland ecosystems. In this innovative
study, we attempt to distinguish between different South
American grassland types in space and time based on
morphological pollen grain characteristics of Poaceae. For
this purpose[60?80 Poaceae pollen grains of 20 grassland
samples were measured using their length, width and pore
diameter as well as annulus width. Samples were taken
from five sites in wet Pa´ramo vegetation from the Late
Pleistocene to the Late Holocene in South Ecuador and
from two sites in the south-eastern Brazilian highlands
(Campos do Altitude) of the same period. Additionally, we
investigated two samples from a Pampa site as well as six
samples from one Campos grassland site in southern Brazil
from the Late Pleistocene to the Late Holocene. Subsets of
samples of the Campos grasslands and of the Pa´ramo were
investigated in order to retrieve more detailed information
on patterns within these vegetation types. Multivariate data
analysis of the complete data set shows changes in taxonomic
composition along an elevational gradient in the
Pa´ramo grasslands. Our results reveal a highly dynamic
development of the individual grassland types; they also
provide interesting information on Poaceae taxa composition
patterns, development and possibly changes in
biodiversity within these ecosystems. Moreover, our data
provide an indication about the origin and dynamics of the
Campos ecosystems in the southern Brazilian highlands
during the Late Pleistocene and the Holocene before and
after the onset of human activities.
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Keywords: |
biodiversity |
grassland |
South America |
Poaceae |
pollen grain morphology |
grain size |
Pampa |
Schüler, L. & Behling, H. (2010): Poaceae pollen grain size as a tool to distinguish past grasslands in South America - a new methodological approach. Vegetation History and Archaeobotany 20, 83-96.
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DOI: 10.1007/s00334-010-0265-z
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Abstract:
Abstract:
Despite the dominance of grasslands during the
last glacial period, especially in South America, the highly
uniform morphology of Poaceae pollen grains has so far
allowed only very few palynological studies based on
Poaceae pollen. In our study we compare two methods of
distinguishing between South American grassland ecosystems
based on quantitative morphology of Poaceae pollen
grains. We investigated data sets from Pa´ramo in southern
Ecuador, Campos de Altitude and Campos in south-eastern
and southern Brazil as well as data sets from the Pampa in
Argentina by measuring the pollen grain length, grain
width, pore diameter and annulus width. Firstly we investigated
the potential influence of chemical treatment of
pollen grains on pollen grain size as well as the measurement
setting for defining the boundary conditions for using
Poaceae pollen grains in a palaeoecological investigation.
Finally the measured pollen grain parameters were analyzed
by comparison of average grain length using
statistical tests. This approach reveals highly significant
differences in average grain size between all grassland
ecosystems. Assuming that a certain grain size range can
be assigned to a certain Poaceae taxon, conclusions about
differences and similarities in taxa composition can be
derived. We used two methods of multivariate data analysis.
One uses the pollen grain parameters directly for a
Principle Component Analysis (PCA). The other is an
already established method in grassland ecology which
defines parameter based pollen grain types to investigate
similarities between grassland ecosystems. Both approaches
confirm the results of the grain length analysis. In this
work we demonstrate that the method we developed has the
potential to provide acquisition of so far inaccessible
information on spatial and temporal patterns and dynamics
of South American grasslands.
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Keywords: |
palynology |
grassland |
South America |
Poaceae |
Pampa |
Paramo |
Rodriguez, F. & Behling, H. (2012): Late Quaternary vegetation, climate and fire dynamics, and evidence of early to mid-Holocene Polylepis forests in the Jimbura region of the southernmost Ecuadorian Andes. Palaeogeography, Palaeoclimatology, Palaeoecology 350-352, 247-257.
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DOI: 10.1016/j.palaeo.2012.07.004
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Abstract:
Abstract:
The vegetation,climate and fire history of high mountain ecosystemsin the southern Ecuadorian Andes are
documented in a continuous pollen and charcoal record,from Lagunas Natosas Forest bog,at 3495 m a.s.l. spanning the late Pleistocene and Holocene periods since 15,930 cal yr BP.The chronology of this record is
based on four radiocarbon dates.Páramo vegetation with abundant Poaceae and Plantago rigida characterized
the Late Glacial(LG)period, implying cold and wet conditions. Slight expansions of mountain forests suggest
warming during the LG. The upper foresl line was lower than today and fire events were rare during the
Pleistocene. During the early and mid-Holocene until 4300 cal yr BP, the area of páramo was markedly smaller and the subpáramo with woody vegetation (Melastomataceae) was larger. The upper mountain forest dominated and the upper forest line shifted to higher elevations. The pollen record provides the first evidence
of the development of Polylepis forests in the southern part of the so-called Andean Depression reflecting
warmer and drier climatic conditions during early and mid-Holocene. The late Holocene after about
4300 cal yr BP is characterized by larger areas of páramo and subpáramo promoted by moister conditions.
These moister conditions and frequent fires may have been the cause of the very rare occurrence or even extinction of Polylepis populations in the Jimbura region. Since ca. 1000 cal yr BP human occupation has altered
the landscape by frequent burning, woodcutting, grazing and cultivation.
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Keywords: |
Ecuador |
palynology |
Holocene |
Andes |
mountain forest |
Polylepis |
fire history |
forest line |
Late Glacial |
Zamora |
Trachte, K. & Bendix, J. (2012): Katabatic Flows and Their Relation to the Formation of Convective Clouds - Idealized Case Studies. Journal of Applied Meteorology and Climatology 51, 1531?1546.
Martinson, G.; Corre, M. & Veldkamp, E. (2012): Responses of nitrous oxide fluxes and soil nitrogen cycling to nutrient additions in montane forests along an elevation gradient in southern Ecuador. Biogeochemistry online , online.
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DOI: 10.1007/s10533-012-9753-9
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Abstract:
Abstract:
Tropical montane forests are commonly limited by N or co-limited by N and P. Projected increases in N deposition in tropical montane regions are thought to be insufficient for vegetation demand and are not therefore expected to affect soil N availability and N2O emissions. We established a factorial Nand P-addition experiment (i.e., N, P, N ? P, and control) across an elevation gradient of montane forests in Ecuador to test these hypotheses: (1) moderate rates of N and P additions are able to stimulate soil-N cycling rates and N2O fluxes, and (2) the magnitude and timing of soil N2O-flux responses depend on the initial nutrient status of the forest soils. Moderate rates of nutrients were added: 50 kg N ha-1 year-1 (in the form of urea) and 10 kg P ha-1 year-1 (in the form of NaH2PO4 . 2H2O) split in two equal applications. We tested the hypotheses by measuring changes in net rates of soil–N cycling and N2O fluxes during the first 2 years (2008??2009) of nutrient manipulation in an oldgrowth premontane forest at 1,000 m, growing on a Cambisol soil with no organic layer, in an old-growth lower montane forest at 2,000 m, growing on a Cambisol soil with an organic layer, and an oldgrowth upper montane rainforest at 3,000 m, growing on a Histosol soil with a thick organic layer. Among the control plots, net nitrification rates were largest at the 1,000-m site whereas net nitrification was not detectable at the 2,000and 3,000-m sites. The already large net nitrification at the 1,000-m site was not affected by nutrient additions, but net nitrification became detectable at the 2,000and 3000-m sites after the second year of N and N + P additions. N2O emissions increased rapidly following N and N ? P additions at the 1,000-m site whereas only smaller increases occurred at the 2,000and 3,000-m sites during the second year of N and N + P additions. Addition of P alone had no effect on net rates of soil N cycling and N2O fluxes at any elevation. Our results showed that the initial soil N status, which may also be influenced by presence or absence of organic layer, soil moisture and temperature as encompassed by the elevation gradient, is a good indicator of how soil N cycling and N2O fluxes may respond to future increases in nutrient additions.
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Keywords: |
phosphorus |
mountain forest |
N2O emissions |
soil N availability |
nutrient manipulation |
nutrient limitation |
wood specific gravity |
aboveground biomass |
environmental gradients |
carbon stocks |
Pilodyn wood tester |
Knoke, T.; Román-Cuesta, R.M.; Weber, M. & Haber, W. (2012): How can climate policy benefit from comprehensive land-use approaches?. Frontiers in Ecology and the Environment 10, 438-445.
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DOI: 10.1890/110203
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Abstract:
Abstract:
Schemes that reward developing countries for the mitigation of greenhouse-gas (GHG) emissions through preservation and restoration of their forests are becoming more common. However, efforts to reduce GHG emissions must also consider food production. This creates an apparent conflict, since agricultural production ? a key driver of GHG emissions as a consequence of forest clearance ? will increase as human populations continue to grow. We argue that a mix of small cropland and forest parcels enables sustainable intensification of agriculture by minimizing soil degradation . Economic analyses of the mixed land-use concept suggest an improvement of long-term economic performance by 19?25% relative to conventional industrial agriculture. Adopting this approach requires farm management plans, landscape zoning, and new instruments to finance sustainable agriculture. We conclude that climate policy and food production are reconciled through an integrative landscape concept that combines sustainable intensification of agriculture and reforestation of abandoned lands.
Hamer, U.; Rumpel, C. & Dignac, M. (2012): Cutin and suberin biomarkers as tracers for the turnover of shoot and root derived organic matter along a chronosequence of Ecuadorian pasture soils. European Journal of Soil Science online, 1-12.
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DOI: 10.1111/j.1365-2389.2012.01476.x
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Abstract:
Abstract:
Forest-to-pasture conversion has been reported to increase soil organic matter (SOM) in mineral topsoils
in the tropical mountain rainforest region of south Ecuador, with subsequent decreases following pasture
abandonment. Until now the mechanisms behind these changes have not been fully understood. To elucidate
their varied preservation patterns, we analysed root- and shoot-derived organic matter and assessed their
contribution to the formation of SOM in topsoils (0?5 cm) on a chronosequence of pastures (Setaria sphacelata
(Schumach.); C4) established after slash and burn of the natural forest (diverse C3 plant species) and an
abandoned pasture site invaded by bracken fern (Pteridium arachnoideum (Kaulf.) Maxon.; C3). Cutin and
suberin biomarkers of the two plant species (grass and bracken) and of forest litter were identified after
saponification and their contribution to SOM was studied by compound-specific stable carbon isotope analyses.
Our results showed specific root and shoot biomarkers for the two plant species and for forest litter, which
often did not correspond to the classification of root-versus shoot-specific monomers reported in the literature.
This illustrates the importance of direct biomarker determination rather than using results from studies with
different plants. Shoot- as well as root-derived OM of forest and grass origin contributed to the stable SOM
pool with decadal turnover times. Forest-derived monomers contributed more to the stable SOM pool compared
with grass-derived monomers. ω-hydroxy carboxylic acids and α,ω-alkanedioic acids of forest origin may have
been stabilized in these tropical soils by bonding to soil minerals. Rapid degradation of grass-derived lipids
from the same compound classes suggests a saturation of the mineral binding capacity. In pasture soils, the
accumulation of SOM was mainly driven by large inputs of root OM. The accumulated SOM during pasture
use is, however, lost rapidly after abandonment.
Unger, M.; Homeier, J. & Leuschner, C. (2012): Effects of soil chemistry on tropical forest biomass and productivity at different elevations in the equatorial Andes. Oecologia 170, 263-274.
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Abstract:
Abstract:
The dependence of aboveground biomass and
productivity of tropical forests on soil fertility is not fully
understood, since previous studies yielded contrasting
results. Here, we quantify aboveground biomass (AGB)
and stem wood production, and examine the impact of soil
chemistry on these parameters in mature tropical forest
stands of the equatorial Andes in Ecuador. In 80 plots of
0.04 ha at four elevation levels (500, 1,000, 1,500 and
2,000 m a.s.l., total sample area = 3.2 ha), we measured ten
important soil chemical parameters, inventoried all trees
¸10 cm dbh and monitored stem diameter growth with
dendrometer tapes in 32 plots. Top canopy height and stem
density signiWcantly decreased from 500 to 2,000 m, while
tree basal area increased and AGB remained invariant
(344 § 17 Mg DM ha¡1, mean § SE) with elevation. Wood
speciWc gravity (WSG) showed a signiWcant, but small,
decrease. Stem wood production decreased from 4.5 to
3.2 Mg DM ha¡1 year¡1 along the transect, indicating a
higher biomass turnover at lower elevations. The only soil
variable that covaried with AGB was exchangeable K in the
topsoil. WSG increased with decreases in N mineralisation
rate, soil pH and extractable Ca and P concentrations.
Structural equation modelling (SEM) revealed that nitrogen
availability acts on stem wood production only indirectly
through a negative relation between N mineralisation rate
and WSG, and a positive eVect of a lowered WSG on stem
growth. The SEM analysis showed neither direct nor indirect
eVects of resin-extractable P on wood production, but a
negative P inXuence on AGB. We conclude that nitrogen
availability signiWcantly inXuences productivity in these
Andean forests, but both N and P are aVecting wood production
mainly indirectly through alterations in WSG and
stem density; the growth-promoting eVect of N is apparently
larger than that of P.
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Keywords: |
Ecuador |
tree growth |
soil nutrients |
aboveground biomass |
wood production |
Wittich, B.; Horna, V.; Homeier, J. & Leuschner, C. (2012): Altitudinal decrease in photosynthetic capacity in tropical trees: A case study from Ecuador and a pantropical literature analysis. Ecosystems 15, 958-973.
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DOI: 10.1007/s10021-012-9556-9
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Abstract:
Abstract:
In tropical mountains, trees are the dominant life
form from sea level to above 4,000-m altitude under
highly variable thermal conditions (range of
mean annual temperatures: <8 to >28C). How
light-saturated net photosynthesis of tropical trees
adapts to variation in temperature, atmospheric
CO2 concentration, and further environmental
factors, that change along elevation gradients,
is not precisely known. With gas exchange
measurements in mature trees, we determined
light-saturated net photosynthesis at ambient
temperature (T) and [CO2] (Asat) of 40 tree species
from 21 families in tropical mountain forests at
1000-, 2000-, and 3000-m elevation in southern
Ecuador. We tested the hypothesis that stand-level
averages of Asat and leaf dark respiration (RD) per
leaf area remain constant with elevation. Standlevel
means of Asat were 8.8, 11.3, and 7.2 lmol
CO2 m-2 s-1; those of RD 0.8, 0.6, and 0.7 lmol
CO2 m-2 s-1 at 1000-, 2000-, and 3000-m elevation,
respectively, with no significant altitudinal
trend. We obtained coefficients of among-species
variation in Asat and RD of 20?53% (n = 10?16 tree
species per stand). Examining our data in the
context of a pan-tropical Asat data base for mature
tropical trees (c. 170 species from 18 sites at variable
elevation) revealed that area-based Asat
decreases in tropical mountains by, on average,
1.3 lmol CO2 m-2 s-1 per km altitude increase (or
by 0.2 lmol CO2 m-2 s-1 per K temperature
decrease). The Asat decrease occurred despite an
increase in leaf mass per area with altitude. Local
geological and soil fertility conditions and related
foliar N and P concentrations considerably influenced
the altitudinal Asat patterns. We conclude
that elevation is an important influencing factor of
the photosynthetic activity of tropical trees. Lowered
Asat together with a reduced stand leaf area
decrease canopy C gain with elevation in tropical
mountains.
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Keywords: |
altitudinal gradient |
foliar N |
foliar P |
leaf dark respiration |
light-saturated net photosynthesis |
tropical lowland forests |
mature trees |
C source limitation |
tropical montane forest |
Brehm, G.; Bodner, F.; Strutzenberger, P.; Hünefeld, F. & Fiedler, K. (2011): Neotropical Eois (Lepidoptera: Geometridae): Checklist, Biogeography, Diversity, and Description Patterns. Annals of the Entomological Society of America 104, 1091-1107.
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Abstract:
Abstract:
The moth genus Eois Hu¨ bner (Lepidoptera: Geometridae: Larentiinae) comprises 254 validly described species, 211 of them (83%) occurring in the Neotropical region, 12% in the Asian-Australian region, and 5% in Africa. A checklist of Neotropical Eois is provided and some taxonomic changes are made. Aplogompha noctilaria (Schaus) is excluded from the genus, and Eois bermellada (Dognin) and Eois fragilis (Warren) are transferred to the genus. Further changes include Eois cellulata (Prout) stat. rev., Eois ambarilla (Dognin) stat. rev., and Eois telegraphica Prout stat. rev. By far, the majority of Eois species (82%) were described between 1891 and 1920; approximately half of all species by just two authors. Within the Neotropical region, the majority of species (55%) were described from the tropical Andes (Colombia, Ecuador, Peru, and Bolivia), followed by Central America and the Caribbean (28%), and the rest of South America (17%). Large regions such as the Amazon basin, eastern South America, but also northern Peru are heavily underrepresented. Regional diversity studies provide evidence that the wet tropical Andes are the diversity hotspot of Eois. From a forested elevational gradient (1,020Ð2,670 m above sea level) in southeastern Ecuador, 154 morphospecies are currently known, with only 12% of them described. Regional species richness in Central America is lower (Costa Rica, 66 observed morphospecies along a gradient from 40 to 2,730 m; 29% described). Total richness of the genus is estimated to be 1,000 species in the Neotropical region. If the low proportions of described species only partly recur in other groups of Neotropical geometrid moths, their number may exceed 19,000 species. A taxonomic revision of Eois will be a prerequisite for comparison of ecological data from different regions.
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Keywords: |
diversity |
Andes |
Larentiinae |
species richness estimate |
Bodner, F.; Strutzenberger, P.; Brehm, G. & Fiedler, K. (2012): Species Richness and Host Specificity among Caterpillar Ensembles on Shrubs in the Andes of Southern Ecuador. Neotropical Entomology n/a, n/a.
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DOI: 10.1007/s13744-012-0066-4
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Abstract:
Abstract:
Caterpillar ensembles were sampled on 16 species of shrubs from the family Asteraceae and the genus Piper (Piperaceae) in open and forest habitats in the Andean montane forest zone of southern Ecuador between August 2007 and May 2009. Trophic affiliations of caterpillars to the host plants were confirmed in feeding trials. Overall, species richness of herbivorous caterpillars was high (191 species across all plants), but varied strongly between ensembles associated with different plant species (2–96 lepidopteran species per shrub species). Ensembles on Piper species were characterized by low effective species numbers and high dominance of one or two species of the Geometridae genus Eois Hübner. Low species number and high dominance were also found on latex-bearing Erato polymnioides, whereas ensembles on two other Asteraceae species were far more diverse and less strongly shaped by a few dominant species. The observed diversity patterns fit well to the concept that anti-herbivore defenses of plants are the major factors regulating associated insect ensembles. Local abundance and geographic range of host plants appear to have less influence. Lepidopteran species feeding on Asteraceae were found to be more generalistic than those feeding on Piper species. We conclude that caterpillar ensembles on most, but not all, studied plant species are defined by a small number of dominant species, which usually are narrow host specialists. This pattern was more distinct on Piper shrubs in forest understory, whereas Asteraceae in disturbed habitats had more open caterpillar ensembles.
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Keywords: |
Lepidoptera |
tropical montane forest |
Asteraceae |
insect herbivores |
Piperaceae |
Castro, L.M.; Calvas, B.; Hildebrandt, P. & Knoke, T. (2012): Avoiding the loss of shade coffee plantations: how to derive conservation payments for risk-averse land-users. Agroforestry Systems online, online.
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DOI: 10.1007/s10457-012-9554-0
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Abstract:
Abstract:
We usually have only limited knowledge about the economic consequences of land-use decisions, thus they are uncertain. We analyze the implications of this uncertainty on conservation payments (CP) to preserve wildlife-friendly shade coffee production in southwest Ecuador, when conversion to maize is the most profitable alternative. Our objective is twofold: First, we analyze the consequences of
applying Stochastic Dominance (SD) to derive CP, an approach making only minimal assumptions about the preferences of farmers. Second, we investigate the effects of land-use diversification to reduce CP by allowing for shade coffee on part of a landholding, and
maize production on what remains. CP derived by SD turned out to be at least twice the amount calculated by an alternative method which maximizes a concave utility function?US$ 166 to US$ 294 ha-1 year-1 instead of US$ 86 ha-1 year-1. Given this result, we
doubt that the assumptions underlying SD are reasonable for farmers, who are known to be riskaverse. Allowing for land-use diversification has a significant impact on CP. The optimal portfolio share of shade coffee is 27 % and for maize 73 % for
moderately risk-averse farmers?without any CP. A larger share of shade coffee is preferable for strongly risk-averse farmers?51 and 49 % maize. The amount of CP necessary to encourage the expansion of shade coffee to 75 %is US$ 40 ha-1 year-1 (for moderately
risk-averse) and US$ 19 ha-1 year-1 (for strongly risk-averse farmers). Stimulating diversification may thus help to significantly reduce CP necessary to preserve less profitable agroforestry options.
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Keywords: |
Biodiversity conservation |
Agroforestry |
conservation payments |
uncertainty |
diversification |
mean–variance |
stochastic dominance |
Silva, B.; Roos, K.; Voss, I.; König, N.; Rollenbeck, R.; Scheibe, R.; Beck, E. & Bendix, J. (2012): Simulating canopy photosynthesis for two competing species of an anthropogenic grassland community in the Andes of southern Ecuador. Ecological Modelling 239, 14-26.
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DOI: 10.1016/j.ecolmodel.2012.01.016
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Abstract:
Abstract:
Tropical mountain forest in the Andes of southeastern Ecuador is regularly destroyed to gain pasture land by cultivating the C4 grass Setaria sphacelata. After recurrent burning of the pastures, the grass is partly outcompeted by the C3 southern bracken (Pteridium arachnoideum). This competition represents the problematic of pasture degradation and increasing deforestation, due to the necessity of new pasture land. Because no information on the growth potential of both species in the Andes of Ecuador is available, a growth simulation model has been improved and properly parameterized with field observations. The measured speciesand site-specific physiological and edaphic parameters are presented in this paper, as well as the model validation with field observations of leaf CO2 assimilation. The validation showed deviations of simulated from observed leaf net assimilation lower than 5% of the observed values. The validated model was run with a fully realistic meteorological forcing of the year 2008 (10 min time step). The main result points to slightly higher growth potential of Setaria with 5879 g m-2 a-1, based on an annual CO2 net assimilation rate of 217 mol CO2m-2 a-1. The calculated growth potential of bracken was 5554 g m-2 a-1, based on the CO2 net assimilation of 197 mol CO2m-2 a-1. In addition, it was shown that decreasing incoming solar radiation and low temperature are favourable weather conditions for bracken in contrary to the pasture grass Setaria.
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Keywords: |
Ecuador |
Setaria sphacelata |
simulation |
photosynthesis |
parameters estimation |
realistic forcing |
southern bracken |
Breuer, L. (2012): Simulating ecosystem functioning of tropical mountainous cloud forests in southern Ecuador. Ecological Modelling 239, 1-2.
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DOI: 10.1016/j.ecolmodel.2012.05.027
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Abstract:
Abstract:
Tropical mountainous cloud forests belong to the most diverse ecosystems on earth. If you ask scientists which features characterize these ecosystems, then the answers are as diverse as is the flora and fauna within them: persistent cloud cover, reduced solar radiation due to cloud cover, distinctly structured vegetation forms, suppressed evapotranspiration as a consequence of high relative humidity, stripping of clouds by tree canopies and resulting large amount of throughfall, reduced canopy heights, high rainfall rates, gnarled tree trunks at increasing altitudes, substantial epiphyte biomass, moss-covered stems, organic rich and typically wet soils, and – last but not least – extremely high biodiversity with a paramount endemism (Bruijnzeel et al., 2011).
Vorpahl, P.; Elsenbeer, H.; Märker, M. & Schröder, B. (2012): How can statistical models help to determine driving factors of landslides?. Ecological Modelling 239, 27-39.
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DOI: 10.1016/j.ecolmodel.2011.12.007
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Abstract:
Abstract:
Landslides are a hazard for humans and artificial structures. From an ecological point of view, they represent an important ecosystem disturbance, especially in tropical montane forests. Here, shallow translational landslides are a frequent natural phenomenon and one local determinant of high levels of biodiversity. In this paper, we apply weighted ensembles of advanced phenomenological models from statistics and machine learning to analyze the driving factors of natural landslides in a tropical montane forest in South Ecuador. We exclusively interpret terrain attributes, derived from a digital elevation model, as proxies to several driving factors of landslides and use them as predictors in our models which are trained on a set of five historical landslide inventories. We check the model generality by transferring them in time and use three common performance criteria (i.e. AUC, explained deviance and slope of model calibration curve) to, on the one hand, compare several state-of-the-art model approaches and on the other hand, to create weighted model ensembles. Our results suggest that it is important to consider more than one single performance criterion.
Approaching our main question, we compare responses of weighted model ensembles that were trained on distinct functional units of landslides (i.e. initiation, transport and deposition zones). This way, we are able to show that it is quite possible to deduce driving factors of landslides, if the consistency between the training data and the processes is maintained. Opening the ?black box? of statistical models by interpreting univariate model response curves and relative importance of single predictors regarding their plausibility, we provide a means to verify this consistency.
With the exception of classification tree analysis, all techniques performed comparably well in our case study while being outperformed by weighted model ensembles. Univariate response curves of models trained on distinct functional units of landslides exposed different shapes following our expectations. Our results indicate the occurrence of landslides to be mainly controlled by factors related to the general position along a slope (i.e. ridge, open slope or valley) while landslide initiation seems to be favored by small scale convexities on otherwise plain open slopes.
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Keywords: |
landslide |
random forest |
tropical montane forest |
statistical modeling |
model comparison |
artificial neuronal network |
classification trees |
boosted regression trees |
generalized linear models |
multivariate adaptive regression splines |
maximum entropy method |
weighted model ensembles |
Dislich, C. & Huth, A. (2012): Modelling the impact of shallow landslides on forest structure in tropical montane forests. Ecological Modelling 239, 40-53.
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DOI: 10.1016/j.ecolmodel.2012.04.016
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Abstract:
Abstract:
Shallow landslides are an important type of natural ecosystem disturbance in tropical montane forests. Due to landslides, vegetation and often also the upper soil layer are removed, and space for primary succession under altered environmental conditions is created. Little is known about how these altered conditions affect important aspects of forest recovery such as the establishment of new tree biomass and species composition. To address these questions we utilize a process-based forest simulation model and develop potential forest regrowth scenarios. We investigate how changes in different trees species characteristics influence forest recovery on landslide sites. The applied regrowth scenarios are: undisturbed regrowth (all tree species characteristics remain like in the undisturbed forest), reduced tree growth (induced by nutrient limitation), reduced tree establishment (due to thicket-forming vegetation and dispersal limitation) and increased tree mortality (due to post-landslide erosion and increased susceptibility). We then apply these scenarios to an evergreen tropical montane forest in southern Ecuador where landslides constitute a major source of natural disturbance. Our most important findings are
(a)
On the local scale of a single landslide tree biomass recovers within the first 80 years after landslides for most scenarios, but it takes at least 200 years for the post-landslide forest to reach a structure (in terms of stem size distribution) similar to a mature forest. On this scale forest productivity is reduced for most regrowth scenarios. Changes in different tree species characteristics produce distinct spatio-temporal patterns of tree biomass distribution in the first decades of recovery within the landslide disturbed area. These patterns can potentially be used for identifying the dominant processes that drive forest recovery on landslide disturbed sites.
(b)
On the larger scale of the landscape overall tree biomass is reduced by 9?15% due to landslide disturbances. Overall forest productivity is only slightly reduced (<6%), but landslides increase landscape heterogeneity and produce hotspots of biomass loss and ?blind spots? of forest productivity. Thus landslides have a strong impact on the distribution of biomass in tropical montane forests.
This study demonstrates that dynamic forest models are useful tools for complementing field based studies on landslides; they allow for testing alternative hypotheses on different sources of heterogeneity across spatial scales and investigating the influence of landslides on long-term forest dynamics.
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Keywords: |
FORMIND |
landslide |
nitrogen |
tropical montane forest |
forest model |
forest dynamics |
soil organic matter |
Hamer, U.; Potthast, K.; Burneo Valdivieso, J.I. & Makeschin, F. (2012): Nutrient stocks and phosphorus fractions in mountain soils of Southern Ecuador after conversion of forest to pasture. Biogeochemistry in press, 1-16.
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DOI: 10.1007/s10533-012-9742-z
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Abstract:
Abstract:
Understanding pasture degradation processes is the key for sustainable land management in the tropical mountain rainforest region of the South Ecuadorian Andes. We estimated the stocks of total carbon and nutrients, microbial biomass and different
P fractions along a gradient of land-uses that is typical of the eastern escarpment of the Cordillera Real i.e., old-growth evergreen lower montane forest, active pastures (17 and 50 years-old), abandoned pastures 10 and 20 years old with bracken fern or successional
vegetation. Conversion of forest to pasture by slashand- burn increased the stocks of SOC, TN, P and S in mineral topsoil of active pasture sites. Microbial growth in pasture soils was enhanced by improved availability of nutrients, C:N ratio, and increased soil pH. Up to 39 %of the total P in mineral soil was stored in the microbial biomass indicating its importance as a dynamic, easily available P reservoir at all sites. At a 17 years-old pasture the stock of NH4F extractable organic P, which is considered to be mineralisable in the short-term, was twice as high as in all other soils. The importance of the NaOH extractable organic Ppool increased with pasture age. Pasture degradation was accelerated by a decline of this P stock, which is essential for the long-term P supply. Stocks of microbial biomass, total N and S had returned to forest levels 10 years after pasture abandonment; soil pH and total P 20 years after growth of successional bush vegetation. Only the C:N ratio increased above forest level indicating an ongoing loss of N after 20 years. Soil nutrient depletion and microbial biomass decline enforced the degradation of pastures on the investigated Cambisol sites.
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Keywords: |
land-use change |
sulphur |
soil organic matter |
soil microbial biomass |
tropical soils |
phosphorus availability |
Ließ, M.; Glaser, B. & Huwe, B. (2012): Making use of the World Reference Base diagnostic horizons for the systematic description of the soil continuum - Application to the tropical mountain soil-landscape of southern Ecuador. CATENA 97, 20 -30.
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DOI: 10.1016/j.catena.2012.05.002
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Abstract:
Abstract:
The World Reference Base for Soil Resources (WRB) (FAO, IUSS Working Group WRB, 2007) at present does not acknowledge the spatial soil continuum, but provides a sound basis to do so. Using methods from statistical learning theory to develop digital soil maps is much more efficient and precise while regionalising soil diagnostic properties instead of complex entities such as the soil units assigned by the WRB. Particularly in
providing spatial soil information displayed in digital soil maps, any aggregation of this spatial soil information to soil units means a loss of information.
The soil landscape can be systematically described in its spatial continuum simply by the vertical order and extent of the WRB diagnostic horizons. The diagnostic horizons are related in their thickness to a standard depth and listed from top to bottom in order of appearance.
Typical diagnostic horizon thickness and occurrence probability were predicted from terrain parameters by classification and regression trees (CART), throughout the research area in southern Ecuador. The two disadvantages of CART, abrupt prediction class boundaries and dependence on the dataset, were addressed by hundredfold model runs on different data subsets, leading to a range of possible predictions. Prediction uncertainty was included in the digital soil maps by calculating these predictions' means and standard deviations as well as by horizon occurrence probability prediction. Model performance was evaluated by means of hundredfold external cross validation.
Terrain parameters were found to have a strong influence on diagnostic topsoil properties. However, no influence on the vertical profile differentiation was observed. Hence predicting horizon thickness and subsoil diagnostic properties was difficult. The systematic description of the soil continuum of this particular soillandscape resulted in histic and stagnic soil parts dominating the first 100 cm of the soil column for most of the area.
Krashevska, V.; Maraun, M.; Rueß, L. & Scheu, S. (2010): Carbon and nutrient limitation of soil microorganisms and microbial grazers in a tropical montane rain forest. Oikos 119, 1020-1028.
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DOI: 10.1111/j.1600-0706.2009.18169.x
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Abstract:
Abstract:
We investigated the role of carbon, nitrogen and phosphorus as limiting factors of microorganisms and microbial grazers
(testate amoebae) in a montane tropical rain forest in southern Ecuador. Carbon (as glucose), nitrogen (as NH4NO3) and
phosphorus (as NaH2PO4) were added separately and in combination bimonthly to experimental plots for 20 months.
By adding glucose and nutrients we expected to increase the growth of microorganisms as the major food resource of
testate amoebae. Th e response of microorganisms to experimental treatments was determined by analysing microbial biomass
(SIR), fungal biomass and microbial community composition as measured by phospholipid fatty acids (PLFAs). We
hypothesized that the response of testate amoebae is closely linked to that of microorganisms. Carbon addition strongly
increased ergosterol concentration and, less pronounced, the amount of linoleic acid as fungal biomarker, suggesting that
saprotrophic fungi are limited by carbon. Microbial biomass and ergosterol concentrations reached a maximum in the
combined treatment with C, N and P indicating that both N and P also were in short supply. In contrast to saprotrophic
fungi and microorganisms in total, testate amoebae suff ered from the addition of C and reached maximum density by the
addition of N. Th e results indicate that saprotrophic fungi in tropical montane rain forests are mainly limited by carbon
whereas gram positive and negative bacteria benefi t from increased availability of P. Testate amoebae suff ered from increased
dominance of saprotrophic fungi in glucose treatments but benefi ted from increased supply of N. Th e results show that testate
amoebae of tropical montane rain forests are controlled by bottom?up forces relying on specifi c food resources rather
than the amount of bacterial biomass with saprotrophic fungi functioning as major antagonists. Compared to temperate
systems microbial food webs in tropical forests therefore may be much more complex than previously assumed with trophic
links being rather specifi c and antagonistic interactions overriding trophic interactions.
Krashevska, V.; Maraun, M. & Scheu, S. (2010): Micro- and Macroscale Changes in Density and Diversity of Testate Amoebae of Tropical Montane Rain Forests of Southern Ecuador. Acta Protozool. 49, 17-28.
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Abstract:
Abstract:
We investigated changes in diversity and density of testate amoebae in epiphytes of trees in tropical montane rain forests of
southern Ecuador. Local ? microscale [height on tree trunk of 0 (base of tree trunk), 1 and 2 m; TH I, TH II and TH III, respectively] and
regional ? macroscale (forests at 1000, 2000 and 3000 m) changes were investigated. At the macroscale diversity and density of testate
amoebae peaked at 2000 m. At the microscale diversity reached a maximum at TH I, whereas density reached a maximum at TH III. The
percentage of empty shells at the macroscale was at a maximum at 2000 m and at the microscale at TH I, whereas the percentage of live
cells was at a maximum at 3000 m and at TH III. The diversity of testate amoebae in epiphytes found in the present study was high (113
species). However, only two to nine species were dominant representing 54?85 percent of total living testate amoebae. The results suggest
significant variations in density and diversity of testate amoebae at both the micro- and macroscale. However, for testate amoebae density
the macroscale appears most important whereas changes in diversity are more pronounced at the microscale.
Krashevska, V.; Maraun, M. & Scheu, S. (2012): How does litter quality affect the community of soil protists (testate amoebae) of tropical montane rainforests?. FEMS Microbiol Ecol 80, 603-607.
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DOI: 10.1111/j.1574-6941.2012.01327.x
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Abstract:
Abstract:
Litter quality and diversity are major factors structuring decomposer communities.
However, little is known on the relationship between litter quality and
the community structure of soil protists in tropical forests. We analyzed the
diversity, density, and community structure of a major group of soil protists of
tropical montane rainforests, that is, testate amoebae. Litterbags containing
pure and mixed litter of two abundant tree species at the study sites (Graffenrieda
emarginata and Purdiaea nutans) differing in nitrogen concentrations were
exposed in the field for 12 months. The density and diversity of testate amoebae
were higher in the nitrogen-rich Graffenrieda litter suggesting that nitrogen
functions as an important driving factor for soil protist communities. No additive
effects of litter mixing were found, rather density of testate amoebae was
reduced in litter mixtures as compared to litterbags with Graffenrieda litter
only. However, adding of high-quality litter to low-quality litter markedly
improved habitat quality, as evaluated by the increase in diversity and density
of testate amoebae. The results suggest that local factors, such as litter quality,
function as major forces shaping the structure and density of decomposer
microfauna that likely feed back to decomposition processes.
Jantz, N. & Behling, H. (2011): A Holocene environmental record reflecting vegetation, climate, and fire variability at the Páramo of Quimsacocha, southwestern Ecuadorian Andes. Vegetation History and Archaeobotany 21, 169-185.
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DOI: 10.1007/s00334-011-0327-x
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Abstract:
Abstract:
We reconstructed the palaeoenvironmental conditions of the last ca. 8000 years in the Tres Lagunas region of the Quimsacocha volcanic basin (ca. 3800 m a.s.l.) in the southwestern Ecuadorian Andes. By means of a pollen and charcoal record, we analysed vegetation, fire, and climate history of this area, which is sensitive to climatic changes of both the Pacific as well as of the eastern Andes and Amazon region. Sediment deposits, pronounced increase of pollen and charcoal concentrations, and pollen taxa reflect warmer and drier conditions in the early to mid-Holocene (~8000 to 3900 cal B.P.). During the late Holocene (2250 to -57 cal B.P.), 5 warm and cold-phases occurred at Quimsacocha. The most prominent cold phase possibly corresponds to the globally recognized Little Ice-Age (LIA; ~600 to 100 cal B.P.). The cold phase signal at Quimsacocha was characterized by a higher abundance of Poaceae, Isoëtes and Gentianella, which favour cold and moist conditions. Frequent charcoal particles can be recorded since the early to mid-Holocene (~7600 B.P.). The high Andean tree species Polylepis underwent several phases of degradation and re-establishment in the basin, which can indicate the use of fire by pre-Columbian settlers to enhance the growth of preferred herb species. The Tres Lagunas record suggests that human populations have been influencing the environment around Quimsacocha since the last ca. 8,000 years.
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Keywords: |
Ecuador |
Holocene |
Paramo |
Palaeoecology |
climate change |
Andes |
Crespo, P.; Bücker, A.; Feyen, J.; Frede, H. & Breuer, L. (2012): Preliminary evaluation of the runoff processes in a remote montane cloud forest basin using Mixing Model Analysis and Mean Transit Time. Hydrological Processes -, -.
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DOI: 10.1002/hyp.8382
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Abstract:
Abstract:
In this study, the Mean Transit Time and Mixing Model Analysis methods are combined to unravel the runoff generation process of the San Francisco River basin (73.5 km2) situated on the Amazonian side of the Cordillera Real in the southernmost Andes of Ecuador. The montane basin is covered with cloud forest, sub-páramo, pasture and ferns. Nested sampling was applied for the collection of streamwater samples and discharge measurements in the main tributaries and outlet of the basin, and for the collection of soil and rock water samples. Weekly to biweekly water grab samples were taken at all stations in the period April 2007–November 2008. Hydrometric data, Mean Transit Time and Mixing Model Analysis allowed preliminary evaluation of the processes controlling the runoff in the San Francisco River basin. Results suggest that flow during dry conditions mainly consists of lateral flow through the C-horizon and cracks in the top weathered bedrock layer, and that all subcatchments have an important contribution of this deep water to runoff, no matter whether pristine or deforested. During normal to low precipitation intensities, when antecedent soil moisture conditions favour water infiltration, vertical flow paths to deeper soil horizons with subsequent lateral subsurface flow contribute most to streamflow. Under wet conditions in forested catchments, streamflow is controlled by near surface lateral flow through the organic horizon. Exceptionally, saturation excess overland flow occurs. By absence of the litter layer in pasture, streamflow under wet conditions originates from the A horizon, and overland flow. Copyright © 2011 John Wiley & Sons, Ltd.
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Keywords: |
Ecuador |
mixing model analysis |
mean transit time |
tracer |
hydrological processes |
cloud forest |
Lotz, T.; Nieschulze, J.; Bendix, J.; Dobbermann, M. & König-Ries, B. (2012): Diverse or uniform? - Intercomparison of two major German project databases for interdisciplinary collaborative functional biodiversity research. Ecological Informatics 8, 10-19.
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DOI: 10.1016/j.ecoinf.2011.11.004
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Abstract:
Abstract:
Research on biodiversity, its relation to ecosystem functioning and services, and the assessment of the impacts of environmental change on biodiversity needs an interdisciplinary perspective. This implies a great diversity of data and data formats gathered mostly in short- to mid-term collaborative research projects. It has been common practice that projects develop specific data management and communication solutions. We compare solutions of two major German collaborative research programs in functional biodiversity research to derive functional commonalities. This in-depth analysis follows five categories of the data life cycle: (i) data acquisition, (ii) metadata management, (iii) database, (iv) exploration, analysis and visualization, and (v) data curation and preservation. The results show that even though both systems were developed completely independently, they reveal comparable overall features and a similar state of implementation. Major focus areas lie in the implementation of comparable metadata schemas and their importance for storage and access strategies for tabular data on the value level. Basic analysis tools and similar management functions are considered. Intensive communication with the users and the orientation of ongoing developments based on user requirements is also important. Both systems are different mostly in specific details which, however, do not influence the overall comparable performance. It should be also emphasized that the same functionality is achieved with completely different software. The choice of software is based on the evaluation of available technologies. Thereby it might be influenced by individual experiences of the developers, but is mainly determined by the data diversity, which forces the usage of flexible technologies to develop adaptable systems. It is concluded that overall features for project databases of collaborative research projects must be supplemented by sophisticated data description, storage, and analysis structures to serve the requirements of integrative functional biodiversity research.
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Keywords: |
metadatabase |
information management system |
collaborative research project |
data acquisition |
data exploration |
data curation |
Münchow, J.; Brenning, A. & Richter, M. (2012): Geomorphic process rates of landslides along a humidity gradient in the tropical Andes. Geomorphology 139-140, 271-284.
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Abstract:
Abstract:
Areas with high landslide activity and diversity were encountered in the tropical Andes of Southern Ecuador under contrasting, semi-arid to perhumid climatic conditions. The objective of this study was to determine and compare geomorphic process rates of shallow landslides along this remarkable humidity gradient and subject to different types of human-made and natural environmental changes. Geomorphic work, geomorphic power and landslide mobilization rate (LMR) were therefore calculated for shallow landslides in two study areas with two separate geological or land use-related subareas each. While landslide ages were known in the perhumid Reserva Biológica San Francisco (RBSF) area, only an approximation of the frequency of critical landslide-triggering rainfall events was available for the semi-arid Masamanaca area. Landslide volumes were estimated by volume–area scaling. Generalized additive models (GAMs) were used as landslide susceptibility models in order to analyze the relative importance of topography, and to downscale LMR values to a fine spatial resolution. LMR in the perhumid RBSF area ranged from ˜2 mm yr-1 in the natural part of this area with tropical mountain rainforests to ˜5 mmyr-1 in the human-influenced part. The semi-arid Masamanaca area, though subject to greater estimation uncertainties, displayed LMR on the order of ˜0.4 to 4 mm yr-1 for shallow landslides. The results provide a basis for the spatially differentiated assessment of landscape evolution and degradation in an area with a close relation between landslide activity, natural vegetation succession and human land use.
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Keywords: |
mass movements |
denudation rate |
geomorphic work |
generalized additive model |