Publications
Found 850 publication(s)
- of type
Happ, J. (2019): The influence of phosphorus and nitrogen addition on leaf properties of herbaceous plants in tropical montane rainforests in southern Ecuador University of Goettingen, bachelor thesis
-
log in to download
-
link
-
view metadata
-
Abstract:
Abstract:
The tropical Andes are one of the most biodiverse hotspots on earth. Though the nutrient-limited systems are affected by anthropogenic nutrient inputs due to industry and agriculture. The NuMEx (Nutrient Manipulation Experiment) project, which was set up in 2008 and is located in southern Ecuador and aims to find out about the consequences of nutrient pollution to herbivore and plant interaction. Therefore experimental plots at three different levels of elevation were fertilised with nitrogen and phosphorus. In this study, fresh leaf samples were collected in May 2018. Plant parameters like leaf area, specific leaf area, leaf toughness and nitrogen content were analysed. Herbivory was examined trough leaf area loss measurements. Changes in these parameters along an elevation gradient from 1000 to 3000 m were analysed. Moreover, the study focussed on the influence of the nutrient addition to the sensible tropical system.
A significant influence of the elevation on most of the leaf morphology parameters was shown. Specific leaf area and leaf nitrogen content showed a significant decrease along the elevation gradient, while the leaves became tougher. The mean leaf area and the leaf area loss gained no significant results; however, the leaf area tended to be smaller within rising elevation. The leaf area loss was highest at 3000 m of elevation. All elevation outcomes, except for the leaf area loss, could be explained by the harsher climatic conditions at higher elevation levels and the relationship between nitrogen content and the leaf traits.
Nutrient addition results on the leaf traits were less clear. Almost no significant influences could be measured. The leaf characteristics showed mostly a clear trend though, except for the leaf area. The leaf area partially increased (mostly under mixed nitrogen and phosphorus addition) and partially decreased (nitrogen treatment) due to the nutrient addition. Specific leaf area, leaf nitrogen content and leaf area loss mostly increased due to the nutrient addition, especially nitrogen and the mixed nitrogen and phosphorus sample contributed to the increase. Leaf toughness whereas decreased. The highest decrease was caused at the plots treated with the nitrogen and phosphorus mix. The results make clear that a high leaf nitrogen content correlates with soft leaves and a high specific leaf area. An analysis of the leaf area loss and the leaf nitrogen content yielded that also these traits are correlated.
-
Keywords: |
NUMEX |
San Francisco |
Bombuscaro |
Cajanuma |
herbivory |
leaf properties |
Wilcke, W.; Velescu, A.; Leimer, S. & Valarezo, C. (2020): Water and Nutrient Budgets of Organic Layers and Mineral Topsoils Under Tropical Montane Forest in Ecuador in Response to 15 Years of Environmental Change. In: Levia, D., Carlyle-Moses, D., Iida, S., Michalzik, B., Nanko, K., Tischer, A. (eds.): Forest-Water Interactions (Ecological Studies 240), Springer, Cham, 565-586.
-
log in to download
-
link
-
view metadata
-
DOI: 10.1007/978-3-030-26086-6_23
-
Abstract:
Abstract:
We quantified the changes in macronutrient storages of the soil in a remote Andean tropical montane rain forest on the rim of the Amazon basin from 1998 to 2013. In the studied 15 years, the N, P, and S fluxes in throughfall+stemflow increased significantly, while those of Ca decreased and of Mg and K remained unchanged. The main reasons for increasing nutrient inputs were Amazonian forest fires. Ca inputs decreased because of a particularly strong Sahara dust deposition event in 1999/2000. On average of the 15 budgeted years, P and K accumulated in the organic layer at a rate doubling their current storages in 197 and 27 years, respectively. The other macronutrients were on average leached from the organic layer, depleting it in 38 (Mg) to 281 years (N). Nutrient leaching was likely favored by enhanced mineralization driven by climate warming. In the upper 30 cm of the mineral soil, all macronutrients accumulated at rates doubling their storages in 57 (Ca) to 601 years (P). Our results demonstrate that the current environmental change increased the nutrient supply of the studied ecosystem. Increased nutrient supply might shift the ecosystem to a new state and change the chemistry of headwater streams.
-
Keywords: |
nitrogen |
phosphorus |
environmental change |
macronutrients |
nutrient storage |
base metals |
sulfur |
Knoke, T.; Paul, C.; Rammig, A.; Gosling, E.; Hildebrandt, P.; Härtl, F.; Peters, T.; Richter, M.; Diertl, K.; Castro, L.M.; Calvas, B.; Ochoa Moreno, S.; Valle-Carrión, L.A.; Hamer, U.; Tischer, A.; Potthast, K.; Windhorst, D.; Homeier, J.; Wilcke, W.; Velescu, A.; Gerique, A.; Pohle, P.; Adams, J.; Breuer, L.; Mosandl, R.; Beck, E.; Weber, M.; Stimm, B.; Silva, B.; Verburg, P.H. & Bendix, J. (2020): Accounting for multiple ecosystem services in a simulation of land-use decisions: Does it reduce tropical deforestation?. Global Change Biology 26( ), 1-22.
-
link
-
view metadata
-
DOI: 10.1111/gcb.15003
-
Abstract:
Abstract:
Abstract Conversion of tropical forests is among the primary causes of global environmental change. The loss of their important environmental services has prompted calls to integrate ecosystem services (ES) in addition to socio-economic objectives in decision-making. To test the effect of accounting for both ES and socio-economic objectives in land-use decisions, we develop a new dynamic approach to model deforestation scenarios for tropical mountain forests. We integrate multi-objective optimization of land allocation with an innovative approach to consider uncertainty spaces for each objective. These uncertainty spaces account for potential variability among decision-makers, who may have different expectations about the future. When optimizing only socio-economic objectives, the model continues the past trend in deforestation (1975–2015) in the projected land-use allocation (2015–2070). Based on indicators for biomass production, carbon storage, climate and water regulation, and soil quality, we show that considering multiple ES in addition to the socio-economic objectives has heterogeneous effects on land-use allocation. It saves some natural forest if the natural forest share is below 38%, and can stop deforestation once the natural forest share drops below 10%. For landscapes with high shares of forest (38%–80% in our study), accounting for multiple ES under high uncertainty of their indicators may, however, accelerate deforestation. For such multifunctional landscapes, two main effects prevail: (a) accelerated expansion of diversified non-natural areas to elevate the levels of the indicators and (b) increased landscape diversification to maintain multiple ES, reducing the proportion of natural forest. Only when accounting for vascular plant species richness as an explicit objective in the optimization, deforestation was consistently reduced. Aiming for multifunctional landscapes may therefore conflict with the aim of reducing deforestation, which we can quantify here for the first time. Our findings are relevant for identifying types of landscapes where this conflict may arise and to better align respective policies.
-
Keywords: |
Ecuador |
biodiversity |
ecosystem services |
landscape restoration |
land allocation |
robust optimization |
Beck, E.; Paladines, P.; Paladines, R.; Matt, F.; Farwig, N. & Bendix, J. (2019): Alexander von Humboldt would have loved it: Estación Científica San Francisco.. Ecotropica 21, 201 99.
Dugger, P.; Blendinger, P.; Boehning-Gaese, K.; Chama, L.; Correia, M.; Dehling, D.; Emer, C.; Farwig, N.; Fricke, E.; Galetti, M.; Garcia, D.; Grass, I.; Heleno, R.; Jacomassa, F.; Morales, S.; Moran, C.; Munoz, M.; Neuschulz, E.; Nowak, L.; Piratelli, A.; Pizo, M.; Quitian, M.; Rogers, H.; Ruggera, R.; Saveedra, F.; Sanchez, M.; Sanchez, R.; Santillan, V.; schabo, D.; Ribeiro da Silva, F.; Timoteo, S.; Traveset, A.; Vollstaedt, M. & Schleuning, M. (2019): Seed‐dispersal networks are more specialized in the Neotropics than in the Afrotropics. Global Ecology and Biogeography 28(2), 248-261.
Santillan, V.; Quitian, M.; Tinoco, B.A.; Zarate, E.; Schleuning, M.; Boehning-Gaese, K. & Neuschulz, E. (2019): Direct and indirect effects of elevation, climate and vegetation structure on bird communities on a tropical mountain. Acta Oecologica 102, 103500.
-
link
-
view metadata
-
DOI: 10.1016/j.actao.2019.103500
-
Abstract:
Abstract:
Climate and vegetation structure are important predictors of biodiversity along mountain slopes. The drivers of elevational biodiversity gradients are not yet fully resolved. For instance, there is little understanding of how direct and indirect effects of elevation shape species communities along mountain slopes. In this study, we identify the main drivers of bird diversity along an elevational gradient spanning 2000 m in the Ecuadorian Andes. We simultaneously tested the direct and indirect effects of elevation, temperature, precipitation and vegetation structure on overall bird diversity and on frugivorous and insectivorous birds, using structural equation models (SEMs). We found that elevation was mostly indirectly associated with bird diversity, mediated via abiotic (i.e., temperature, precipitation) and biotic (i.e., vegetation structure) factors. We found consistent positive effects of temperature and vegetation structure and negative effects of precipitation on overall bird diversity and on frugivorous and insectivorous birds. In addition, elevation was directly, positively associated with insectivore richness and abundance, but not with that of frugivores. Our results show that climatic factors and vegetation structure jointly shape the richness of bird communities on tropical mountains. However, other factors, such as biotic interactions or different evolutionary histories of lowland and highland communities, may additionally contribute to elevational patterns in bird diversity. Thus, species communities across tropical mountain slopes are shaped by a multitude of abiotic and biotic factors that need to be studied simultaneously for a mechanistic understanding of patterns in biodiversity.
-
Keywords: |
avian diversity patterns |
Schleuning, M.; Neuschulz, E.; Albrecht, J.; Bender, I.M.; Bowler, D.; Dehling, D.; Fritz, S.; Hof, C.; Mueller, T.; Nowak, L.; Sorensen, M.; Boehning-Gaese, K. & Kissling, W. (2020): Trait-Based Assessments of Climate-Change Impacts on Interacting Species. Trends in Ecology and Evolution xxx-xxx, xxx-xxx.
-
link
-
view metadata
-
DOI: 10.1016/j.tree.2019.12.010
-
Abstract:
Abstract:
Plant–animal interactions are fundamentally important in ecosystems, but have often been ignored by studies of climate-change impacts on biodiversity. Here, we present a trait-based framework for predicting the responses of interacting plants and animals to climate change. We distinguish three pathways along which climate change can impact interacting species in ecological communities: (i) spatial and temporal mismatches in the occurrence and abundance of species, (ii) the formation of novel interactions and secondary extinctions, and (iii) alterations of the dispersal ability of plants. These pathways are mediated by three kinds of functional traits: response traits, matching traits, and dispersal traits. We propose that incorporating these traits into predictive models will improve assessments of the responses of interacting species to climate change.
-
Keywords: |
plants |
functional traits |
global change |
animals |
ecological networks |
dispersal |
DFG FOR2730 - RESPECT (2020): Tabebuia Bulletin, Issue 7. Laboratory for Climatology and Remote Sensing (LCRS), University of Marburg, Marburg, Germany.
Seidel, J.; Trachte, K.; Orellana-Alvear, J.; Figueroa, R.; Celleri, R.; Bendix, J.; Fernandez, C. & Huggel, C. (2019): Precipitation Characteristics at Two Locations in the Tropical Andes by Means of Vertically Pointing Micro-Rain Radar Observations. Remote Sensing 11(24), 2985.
Bogner, F.; Bendix, J. & Beck, E. 2019: El Bosque Tropical de Montaña - Hotspot de Biodiversidad. (Naturaleza y Cultura Internacional, (Loja, Ecuador).
Quichimbo Miguitama, P.G.; Jiménez, L.S.; Veintimilla, D.; Potthast, K.; Tischer, A.; Günter, S.; Mosandl, R. & Hamer, U. (2019): Nutrient dynamics in an Andean forest region: a case study of exotic and native species plantations in southern Ecuador. New Forests -, 1 - 22.
Haug, I.; Setaro, S. & Suarez, J.P. (2019): Species composition of arbuscular mycorrhizal communities changes with elevation in the Andes of South Ecuador. PLOS ONE 14(8), 1-19.
-
log in to download
-
link
-
view metadata
-
DOI: 10.1371/journal.pone.0221091
-
Abstract:
Abstract:
Arbuscular mycorrhizal fungi (AMF) are the most prominent mycobionts of plants in the tropics, yet little is known about their diversity, species compositions and factors driving AMF distribution patterns. To investigate whether elevation and associated vegetation type affect species composition, we sampled 646 mycorrhizal samples in locations between 1000 and 4000 m above sea level (masl) in the South of Ecuador. We estimated diversity, distribution and species compositions of AMF by cloning and Sanger sequencing the 18S rDNA (the section between AML1 and AML2) and subsequent derivation of fungal OTUs based on 99% sequence similarity. In addition, we analyzed the phylogenetic structure of the sites by computing the mean pairwise distance (MPD) and the mean nearest taxon difference (MNTD) for each elevation level. It revealed that AMF species compositions at 1000 and 2000 masl differ from 3000 and 4000 masl. Lower elevations (1000 and 2000 masl) were dominated by members of Glomeraceae, whereas Acaulosporaceae were more abundant in higher elevations (3000 and 4000 masl). Ordination of OTUs with respect to study sites revealed a correlation to elevation with a continuous turnover of species from lower to higher elevations. Most of the abundant OTUs are not endemic to South Ecuador. We also found a high proportion of rare OTUs at all elevations: 79–85% of OTUs occurred in less than 5% of the samples. Phylogenetic community analysis indicated clustering and evenness for most elevation levels indicating that both, stochastic processes and habitat filtering are driving factors of AMF community compositions.
-
Keywords: |
species |
arbuscular mycorrhiza |
Andes |
Arbuscular mycorrhizal fungi |
Orellana-Alvear, J.; Celleri, R.; Rollenbeck, R. & Bendix, J. (2019): Optimization of X-Band Radar Rainfall Retrieval in the Southern Andes of Ecuador Using a Random Forest Model. Remote Sensing 11(14), 1632.
-
download
-
link
-
view metadata
-
DOI: 10.3390/rs11141632
-
Abstract:
Abstract:
Despite many eorts of the radar community, quantitative precipitation estimation (QPE)
from weather radar data remains a challenging topic. The high resolution of X-band radar imagery
in space and time comes with an intricate correction process of reflectivity. The steep and high
mountain topography of the Andes enhances its complexity. This study aims to optimize the rainfall
derivation of the highest X-band radar in the world (4450 m a.s.l.) by using a random forest (RF)
model and single Plan Position Indicator (PPI) scans. The performance of the RFmodel was evaluated
in comparison with the traditional step-wise approach by using both, the Marshall-Palmer and a
site-specific Z–R relationship. Since rain gauge networks are frequently unevenly distributed and
hardly available at real time in mountain regions, bias adjustment was neglected. Results showed an
improvement in the step-wise approach by using the site-specific (instead of the Marshall-Palmer)
Z–R relationship. However, both models highly underestimate the rainfall rate (correlation coecient
< 0.69; slope up to 12). Contrary, the RF model greatly outperformed the step-wise approach in
all testing locations and on dierent rainfall events (correlation coecient up to 0.83; slope = 1.04).
The results are promising and unveil a dierent approach to overcome the high attenuation issues
inherent to X-band radars.
-
Keywords: |
South Ecuador |
random forest |
radar |
calibration |
Cajas National Park |
Wilcke, W.; Velescu, A.; Leimer, S.; Bigalke, M.; Boy, J. & Valarezo, C. (2019): Temporal Trends of Phosphorus Cycling in a Tropical Montane Forest in Ecuador During 14 Years. Journal of Geophysical Research: Biogeosciences 124, 1370-1386.
-
log in to download
-
link
-
view metadata
-
DOI: 10.1029/2018JG004942
-
Abstract:
Abstract:
Increased bioavailability of P can have a negative impact on plant biodiversity. In an approximately 9‐ha catchment under N + P‐limited megadiverse tropical montane forest in Ecuador, we budgeted all major P fluxes and determined whether the P fluxes changed from 1999 to 2013. Furthermore, we assessed which external drivers (rainfall, total P and acid deposition) caused this potential change. Mean (±SD) annual P deposition (bulk+dry) was 240 ± 270 mg/m2, with the SD reflecting the interannual variation. The annual P flux to the soil via throughfall+stemflow+litterfall was 1,400 ± 170 mg/m2 of which 18 ± 9.2% was leached to below the organic layer. The mineral soil retained 80 ± 12% of the P leached from the organic layer. The mean annual P weathering rate was 79 ± 63 mg/m2. The sum of P fluxes was approximately 5 times larger above than below the mineral soil surface, illustrating that P was tightly cycled in the biological part of the forest. The mean annual canopy budget was negative (−120 ± 280 mg/m2); that is, P was leached from the canopy. Throughfall was the largest source of dissolved P. The P catchment budget (total deposition‐streamflow) was positive (200 ± 270 mg/m2); that is, P was retained, mainly in the soil organic layer. From 1999 to 2013, P fluxes with throughfall, stemflow, and streamflow increased significantly. The strongest driver of the P budgets of the canopy and the catchment was total P deposition. Our results demonstrate that mainly biological processes retained deposited P in the vegetation and the organic layer enhancing the internal P cycle.
-
Keywords: |
litterfall |
temporal trends |
catchment budget |
weathering rates |
phosphorus fluxes |
González-Jaramillo, V.; Fries, A. & Bendix, J. (2019): AGB Estimation in a Tropical Mountain Forest (TMF) by Means of RGB and Multispectral Images Using an Unmanned Aerial Vehicle (UAV). Remote Sensing 11(12), 1-22.
-
download
-
link
-
view metadata
-
DOI: 10.3390/rs11121413
-
Abstract:
Abstract:
The present investigation evaluates the accuracy of estimating above-ground biomass (AGB)
by means of two dierent sensors installed onboard an unmanned aerial vehicle (UAV) platform
(DJI Inspire I) because the high costs of very high-resolution imagery provided by satellites or light
detection and ranging (LiDAR) sensors often impede AGB estimation and the determination of
other vegetation parameters. The sensors utilized included an RGB camera (ZENMUSE X3) and a
multispectral camera (Parrot Sequoia), whose images were used for AGB estimation in a natural
tropical mountain forest (TMF) in Southern Ecuador. The total area covered by the sensors included
80 ha at lower elevations characterized by a fast-changing topography and dierent vegetation covers.
From the total area, a core study site of 24 ha was selected for AGB calculation, applying two dierent
methods. The firstmethod used the RGB images and applied the structure formotion (SfM) process to
generate point clouds for a subsequent individual tree classification. Per the classification at tree level,
tree height (H) and diameter at breast height (DBH) could be determined, which are necessary input
parameters to calculate AGB (Mg ha 1) by means of a specific allometric equation for wet forests.
The second method used the multispectral images to calculate the normalized dierence vegetation
index (NDVI), which is the basis for AGB estimation applying an equation for tropical evergreen
forests. The obtained results were validated against a previous AGB estimation for the same area
using LiDAR data. The study found two major results: (i) The NDVI-based AGB estimates obtained
by multispectral drone imagery were less accurate due to the saturation eect in dense tropical forests,
(ii) the photogrammetric approach using RGB images provided reliable AGB estimates comparable
to expensive LiDAR surveys (R2: 0.85). However, the latter is only possible if an auxiliary digital
terrain model (DTM) in very high resolution is available because in dense natural forests the terrain
surface (DTM) is hardly detectable by passive sensors due to the canopy layer, which impedes
ground detection.
-
Keywords: |
Ecuador |
mountain rainforest |
UAV |
Biomass |
Drone |
Guallpa, M.; Orellana-Alvear, J. & Bendix, J. (2019): Tropical Andes Radar Precipitation Estimates Need High Temporal and Moderate Spatial Resolution. Water 11(5), 1-22.
-
download
-
link
-
view metadata
-
DOI: 10.3390/w11051038
-
Abstract:
Abstract:
Weather radar networks are an excellent tool for quantitative precipitation estimation
(QPE), due to their high resolution in space and time, particularly in remote mountain areas such as
the Tropical Andes. Nevertheless, reduction of the temporal and spatial resolution might severely
reduce the quality of QPE. Thus, the main objective of this study was to analyze the impact of spatial
and temporal resolutions of radar data on the cumulative QPE. For this, data from the world’s highest
X-band weather radar (4450 m a.s.l.), located in the Andes of Ecuador (Paute River basin), and from
a rain gauge network were used. Dierent time resolutions (1, 5, 10, 15, 20, 30, and 60 min) and
spatial resolutions (0.5, 0.25, and 0.1 km) were evaluated. An optical flow method was validated
for 11 rainfall events (with dierent features) and applied to enhance the temporal resolution of
radar data to 1-min intervals. The results show that 1-min temporal resolution images are able to
capture rain event features in detail. The radar–rain gauge correlation decreases considerably when
the time resolution increases (r from 0.69 to 0.31, time resolution from 1 to 60 min). No significant
dierence was found in the rain total volume (3%) calculated with the three spatial resolution data.
A spatial resolution of 0.5 km on radar imagery is suitable to quantify rainfall in the AndesMountains.
This study improves knowledge on rainfall spatial distribution in the Ecuadorian Andes, and it will
be the basis for future hydrometeorological studies
-
Keywords: |
Cuenca |
radar |
rainfall |
Paute |
Graefe, S.; Fang, D. & Butz, P. (2019): Water residence times in trees of a neotropical dry forest. Trees 1, 1–7.
Butz, P.; Hölscher, D.; Cueva, E. & Graefe, S. (2018): Tree Water Use Patterns as Influenced by Phenology in a Dry Forest of Southern Ecuador. Frontiers in Plant Science 9, 945.
Raffelsbauer, V.; Spannl, S.; Peña , K.; Pucha Cofrep, D.A.; Steppe, K. & Bräuning, A. (2019): Tree Circumference Changes and Species-Specific Growth Recovery After Extreme Dry Events in a Montane Rainforest in Southern Ecuador. Frontiers in Plant Sciences 10, 342.
-
log in to download
-
link
-
view metadata
-
DOI: 10.3389/fpls.2019.00342
-
Abstract:
Abstract:
Under drought conditions, even tropical rainforests might turn from carbon sinks to sources, and tree species composition might be altered by increased mortality. We monitored stem diameter variations of 40 tree individuals with stem diameters above 10 cm belonging to eleven different tree genera and three tree life forms with high-resolution dendrometers from July 2007 to November 2010 and additionally March 2015 to December 2017 in a tropical mountain rainforest in South Ecuador, a biodiversity hotspot with more than 300 different tree species belonging to different functional types. Although our study area receives around 2200 mm of annual rainfall, dry spells occur regularly during so-called “Veranillo del Niño” (VdN) periods in October-November. In climate change scenarios, droughts are expected with higher frequency and intensity as today. We selected dry intervals with a minimum of four consecutive days to examine how different tree species respond to drought stress, raising the question if some species are better adapted to a possible higher frequency and increasing duration of dry periods. We analyzed the averaged species-specific stem shrinkage rates and recovery times during and after dry periods. The two deciduous broadleaved species Cedrela montana and Handroanthus chrysanthus showed the biggest stem shrinkage of up to 2 mm after 10 consecutive dry days. A comparison of daily circumference changes over 600 consecutive days revealed different drought responses between the families concerning the percentage of days with stem shrinkage/increment, ranging from 27.5 to 72.5% for Graffenrieda emarginata to 45–55% for Podocarpus oleifolius under same climate conditions. Moreover, we found great difference of recovery times after longer-lasting (i.e., eight to ten days) VdN drought events between the two evergreen broadleaved species Vismia cavanillesiana and Tapirira guianensis. While Vismia replenished to pre-VdN stem circumference after only 5 days, Tapirira needed 52 days on average to restore its circumference. Hence, a higher frequency of droughts might increase inter-species competition and species-specific mortality and might finally alter the species composition of the ecosystem.
-
Keywords: |
tree growth |
DFG FOR2730 - RESPECT (2019): Tabebuia Bulletin, Issue 6. Laboratory for Climatology and Remote Sensing (LCRS), University of Marburg, Marburg, Germany.
-
download
-
link
-
view metadata
-
DOI: 10.5678/lcrs/for2730.cit.1736
-
Abstract:
Abstract:
The first Tabebuia Bulletin of our new Research Unit RESPECT summarizes the installation of our new plot system including the measuring devices and first verification of the newly established methods. First research achievements include the following aspects: plant functional types (PFT), water and carbon fluxes, tree above- and belowground traits, soil development, photosynthetic gas exchange measurements, abiotic covariates, functional trait diversity and herbivory, and optimization of biomass gain on pastures. Our partner NCI reports advances in the establishment of newly protected areas and the Ecuador’s INABIO institution introduces itself. Videos of our previous research are available via our website and data warehouse, which now also offers new search features for publications as well as upload information.
-
Keywords: |
Ecuador |
Newsletter |
Tabebuia Bulletins |
Santillan, V.; Quitian, M.; Tinoco, B.A.; Zarate, E.; Schleuning, M.; Boehning-Gaese, K. & Neuschulz, E. (2018): Different responses of taxonomic and functional bird diversity to forest fragmentation across an elevational gradient. Oecologia x, x-x.
Santillan, V.; Quitian, M.; Tinoco, B.A.; Zarate, E.; Schleuning, M.; Boehning-Gaese, K. & Neuschulz, E. (2018): Temperature and precipitation, but not resource availability drive spatio-temporal variation in bird assemblages along a tropical elevational gradient. PlosOne x, x-x.
Quitian, M.; Santillan, V.; Espinosa, C.I.; Homeier, J.; Boehning-Gaese, K.; Schleuning, M. & Neuschulz, E. (2018): Direct and indirect effects of plant and frugivore diversity on structural and functional components of fruit removal. Oecologia x, x-x.
Quitian, M.; Santillan, V.; Bender, I.M.; Espinosa, C.I.; Homeier, J.; Boehning-Gaese, K.; Schleuning, M. & Neuschulz, E. (2018): Functional responses of avian frugivores to variation of fruit resources in natural and fragmented forests. Functional Ecology x, x-x.
Hanz, D.; Boehning-Gaese, K.; Ferger, S.; Fritz, S.; Neuschulz, E.; Quitian, M.; Santillan, V.; Töpfer, T. & Schleuning, M. (2018): Functional and phylogenetic diversity of bird assemblages are filtered by different environmental drivers. Journal of Biogepgraphy x, x-x.
Bender, I.M.; Kissling, W.; Blendinger, P.; Hensen, I.; Kühn, I.; Munoz, M.; Neuschulz, E.; Nowak, L.; Quitian, M.; Saavedra, F.; Santillan, V.; Töpfer, T.; Wiegand, T.; Dehling, D. & Schleuning, M. (2018): Morphological trait matching shapes plant-frugivore networks across the Andes. Ecography 41(11), 1910-1919.
Bruelheide, H.; Nadrowski, K.; Assmann, T.; Bauhus, J.; Both, S.; Buscot, F.; Chen, X.; Ding, B.; Durka, W. & Erfmeier, A. (2014): Designing forest biodiversity experiments: general considerations illustrated by a new large experiment in subtropical China. Methods in Ecology and Evolution 5(1), 74--89.
Campozano, L.; Trachte, K.; Celleri, R.; Samaniego, E.; Bendix, J.; Cristóbal, A. & Mejia, J.F. (2018): Climatology and Teleconnections of Mesoscale Convective Systems in an Andean Basin in Southern Ecuador: The Case of the Paute Basin. Advances in Meteorology 2018, 1-13.
-
log in to download
-
link
-
view metadata
-
DOI: 10.1155/2018/4259191
-
Abstract:
Abstract:
Mesoscale convective systems (MCSs) climatology, the thermodynamic and dynamical variables, and teleconnections influencing MCSs development are assessed for the Paute basin (PB) in the Ecuadorian Andes from 2000 to 2009. The seasonality of MCSs occurrence shows a bimodal pattern, with higher occurrence during March-April (MA) and October-November (ON), analogous to the regional rainfall seasonality. The diurnal cycle of MCSs shows a clear nocturnal occurrence, especially during the MA and ON periods. Interestingly, despite the higher occurrence of MCSs during the rainy seasons, the monthly size relative frequency remains fairly constant throughout the year. On the east of the PB, the persistent high convective available potential and low convective inhibition values from midday to nighttime are likely related to the nocturnal development of the MCSs. A significant positive correlation between the MCSs occurrence to the west of the PB and the Trans-Niño index was found, suggesting that ENSO is an important source of interannual variability of MCSs frequency with increasing development of MCSs during warm ENSO phases. On the east of the PB, the variability of MCSs is positively correlated to the tropical Atlantic sea surface temperature anomalies south of the equator, due to the variability of the Atlantic subtropical anticyclone, showing main departures from this relation when anomalous conditions occur in the tropical Pacific due to ENSO.
-
Keywords: |
Andes |
Meteorology |
Trachte, K. (2018): Atmospheric Moisture Pathways to the Highlands of the Tropical Andes: Analyzing the Effects of Spectral Nudging on Different Driving Fields for Regional Climate Modeling. Atmosphere 9(11), 1-24.
Carrillo Rojas, G.; Silva, B.; Rollenbeck, R.; Celleri, R. & Bendix, J. (2018): The breathing of the Andean highlands: Net ecosystem exchange and evapotranspiration over the páramo of southern Ecuador. Agricultural and Forest Meteorology 265, 30-47.
-
log in to download
-
link
-
view metadata
-
DOI: 10.1016/j.agrformet.2018.11.006
-
Abstract:
Abstract:
Atmospheric carbon (CO2) exchange, evapotranspiration (ET) processes, and their interactions with climatic drivers across tropical alpine grasslands are poorly understood. This lack of understanding is particularly evident for the páramo, the highest vegetated frontier in the northern Andes, the main source of water for inter-Andean cities, and a large carbon storage area. Studies of CO2 and ET fluxes via the standard Eddy Covariance (EC) technique have never been applied to this region, limiting the understanding of diurnal / nocturnal exchanges and budget estimations. In this paper, we report the first EC analysis conducted on the Andean páramo (3765?m a.s.l.); this analysis measured CO2, ET, and micrometeorological variables over two years (2016–2018) to understand their interactions with climatic / biophysical controls. The páramo was found to be a source of CO2 and exhibited a net positive exchange (mean = +99?±?30 gC m?2 per year). The light-responses of net CO2 exchange and the primary productivity were correlated and model-parameterized. Evapotranspiration was 635?±?9?mm per year (51% of the annual rainfall total), and we obtained crop coefficients for the dominant vegetation (Tussock grass) based on reference-ET models FAO56 and ASCE-ERWI (0.90 and 0.78, respectively). We also compared our results to those from other high-altitude (alpine) and high-latitude grasslands (tundra). Finally, we demonstrate that our measurement period is representative of the páramo’s longer-term climate dynamics. Our investigation contributes to the body of knowledge on the land surface-atmosphere processes of the tropical Andes and supports decision-making about ecosystem services management and the preservation of this vulnerable biome.
-
Keywords: |
Ecuador |
carbon |
Paramo |
Evapotranspiration |
Tropical Andes |
Eddy covariance |