Publicaciones
Se encontró/encontraron 509 Publicaciones(s).
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Barczyk, M.; Acosta Rojas, D.C.; Espinosa, C.I.; Schleuning, M. & Neuschulz, E.L. (2024): Seedling recruitment of small-seeded and large-seeded species in forests and pastures in southern Ecuador. Basic and Applied Ecology 75, 44-52.
Acosta Rojas, D.C.; Barczyk, M.; Espinosa, C.I.; Tinoco, B.A.; Neuschulz, E.L. & Schleuning, M. (2024): Systematic reduction in seed rain of large-seeded and endozoochorous species in pastures compared to forests along a tropical elevational gradient. Applied Vegetation Science 27, e12780.
Cordova, M.; Orellana-Alvear, J.; Bendix, J.; Rollenbeck, R. & Celleri, R. (2024): Large-scale dynamics of extreme precipitation in the tropical Andes: combining weather radar observations and reanalysis data. Meteorology and Atmospheric Physics 136(4), 27.
Álvarez-Estrella, J.; Muñoz, P.; Bendix, J.; Contreras, P. & Celleri, R. (2024): Enhancing Peak Runoff Forecasting through Feature Engineering Applied to X-Band Radar Data. Water 16(7), 968.
Guillen Otero, T.; Kessler, M. & Homeier, J. (2024): Fern mycorrhizae do not respond to fertilization in a tropical montane forest. Plant-Environment Interactions 5(2), e10139.
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DOI: 10.1002/pei3.10139
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Resumen:
Resumen:
Ferns are known to have a lower incidence of mycorrhization than angiosperms. It
has been suggested that this results from carbon being more limiting to fern growth
than nutrient availability, but this assertion has not been tested yet. In the present
study, we took advantage of a fertilization experiment with nitrogen and phosphorus
on cloud forest plots of the Ecuadorean Andes for 15 years. A previous analysis
revealed changes in the abundances of fern species in the fertilized plots compared
to the control plots and hypothesized that this might be related to the responses of
the mycorrhizal relationships to nutrient availability. We revisited the plots to assess
the root-associated
fungal communities of two epiphytic and two terrestrial fern
species that showed shifts in abundance. We sampled and analyzed the roots of 125
individuals following a metabarcoding approach. We recovered 1382 fungal ASVs, with
a dominance of members of Tremellales (Basidiomycota) and Heliotales (Ascomycota).
The fungal diversity was highly partitioned with little overlap between individuals. We
found marked differences between terrestrial and epiphytic species, with the latter
fundamentally missing arbuscular mycorrhizal fungi (AMF). We found no effect of
fertilization on the diversity or relative abundance of the fungal assemblages. Still, we
observed a direct impact of phosphorus fertilization on its concentration in the fern
leaves. We conclude that fern–fungi relationships in the study site are not restricted
by nutrient availability and suggest the existence of little specificity on the fungal
partners relative to the host fern species.
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Keywords: |
Ecuador |
nitrogen |
phosphorus |
fertilization |
Arbuscular mycorrhizal fungi |
Schoen, J.; Tiede, Y.; Becker, M.; Donoso, D.A.; Homeier, J.; Limberger, O.; Bendix, J.; Farwig, N. & Brandl, R. (2023): Effects of leaf traits of tropical trees on the abundance and body mass of herbivorous arthropod communities. PLOS ONE -(-), 1 - 21.
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DOI: 10.1371/journal.pone.0288276
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Resumen:
Resumen:
In tropical forests, herbivorous arthropods remove between 7% up to 48% of leaf area,
which has forced plants to evolve defense strategies. These strategies influence the palat-
ability of leaves. Palatability, which reflects a syndrome of leaf traits, in turn influences both
the abundance and the mean body mass not only of particular arthropod taxa but also of the
total communities. In this study, we tested two hypotheses: (H1) The abundance of two
important chewer guilds (‘leaf chewers’ and ‘rostrum chewers’), dominant components of
arthropod communities, is positively related to the palatability of host trees. (H2) Lower pal-
atability leads to an increased mean body mass of chewers (Jarman-Bell principle). Arthro-
pods were collected by fogging the canopies of 90 tropical trees representing 31 species in
three plots at 1000 m and three at 2000 m a.s.l. Palatability was assessed by measuring
several ‘leaf traits’ of each host tree and by conducting a feeding trial with the generalist her-
bivore Gryllus assimilis (Orthoptera, Gryllidae). Leaf traits provided partial support for H1, as
abundance of leaf chewers but not of rostrum chewers was positively affected by the experi-
mentally estimated palatability. There was no support for H2 as neither leaf traits nor experi-
mentally estimated palatability affected the mean body mass of leaf chewers. The mean
body mass of rostrum chewers was positively related to palatability. Thus, leaf traits and
experimentally estimated palatability influenced the abundance and mean body mass of
chewing arthropods on the community level. However, the data were not consistent with the
Jarman-Bell principle. Overall, our results suggest that the palatability of leaves is not
among the dominant factors influencing abundance and mean body mass of the community of chewing arthropod herbivores. If other factors, such as the microclimate, predation or fur-
ther (a-)biotic interactions are more important has to be analyzed in refined studies.
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Keywords: |
insect herbivores |
abundance |
morphological traits |
leaf functional traits |
Jarman-Bell principle |
leaf chewers |
rostrum chewers |
palatability |
Rollenbeck, R.; Orellana-Alvear, J.; Bendix, J.; Rodriguez, R.; Pucha-Cofrep, F.; Guallpa, M.; Fries, A. & Celleri, R. (2022): The Coastal El Niño Event of 2017 in Ecuador and Peru: A Weather Radar Analysis. Remote Sensing 14(4), 824.
Laughlin, D.; Siefert, A.; Fleri, J.; Tumber-Davila, S.; Hammond, W.; Sabatini, F.; Damasceno, G.; Aubin, I.; Field, R.; Hatim, M.; Jansen, S.; Lenoir, J.; Lens, F.; McCarthy, J.; Niinemets, Ü.; Phillips, O.; Attorre, F.; Bergeron, Y.; Bruun, H.; Byun, C.; Custerevska, R.; Dengler, J.; De Sanctis, M.; Dolezal, J.; Jimenez-Alfaro, B.; Herault, B.; Homeier, J.; Kattge, J.; Meir, P.; Mencuccini, M.; Noroozi, J.; Nowak, A.; Penuelas, J.; Schmidt, M.; Skvorc, Z.; Sultana, F.; Magana Ugarte, R. & Bruelheide, H. (2023): Rooting depth and xylem vulnerability are independent woody plant traits jointly selected by aridity, seasonality, and water table depth. New Phytologist XX(XX), X-Y.
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DOI: 10.1111/nph.19276
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Resumen:
Resumen:
Evolutionary radiations of woody taxa within arid environments were made possible by multiple trait innovations including deep roots and embolism-resistant xylem, but little is known about how these traits have coevolved across the phylogeny of woody plants or how they jointly influence the distribution of species.
We synthesized global trait and vegetation plot datasets to examine how rooting depth and xylem vulnerability across 188 woody plant species interact with aridity, precipitation seasonality, and water table depth to influence species occurrence probabilities across all biomes.
Xylem resistance to embolism and rooting depth are independent woody plant traits that do not exhibit an interspecific trade-off. Resistant xylem and deep roots increase occurrence probabilities in arid, seasonal climates over deep water tables. Resistant xylem and shallow roots increase occurrence probabilities in arid, nonseasonal climates over deep water tables. Vulnerable xylem and deep roots increase occurrence probabilities in arid, nonseasonal climates over shallow water tables. Lastly, vulnerable xylem and shallow roots increase occurrence probabilities in humid climates.
Each combination of trait values optimizes occurrence probabilities in unique environmental conditions. Responses of deeply rooted vegetation may be buffered if evaporative demand changes faster than water table depth under climate change.
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Keywords: |
cavitation |
drougt avoider |
drought resistant |
water availability |
Alvarez Figueroa, P.A.; Velescu, A.; Pierick, K.; Homeier, J. & Wilcke, W. (2023): Carbon stable isotope ratios of dissolved organic matter as a tool to identify its sources and transformations in a tropical montane forest in Ecuador. Environmental Science and Technology 57, 14983−14993.
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DOI: 10.1021/acs.est.3c01623
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Resumen:
Resumen:
Dissolved organic matter (DOM) contributes to forest C cycling. We assessed temporal variability, sources, and transformations of DOM during four years in a tropical montane forest with the help of stable C isotope ratios (δ13C values). We measured δ13C values of DOM in rainfall (RF), throughfall (TF), stemflow (SF), litter leachate (LL), soil solutions at the 0.15 and 0.30 m depths (SS15, SS30), and streamflow (ST)with TOC-IRMS. The δ13C values of DOM did not vary seasonally. We detected an event with a high δ13C value likely attributable to black carbon from local pasture fires. The mean δ13C values of DOM outside the event decreased in the order, RF (−26.0 ± 1.3‰) > TF (−28.7 ± 0.3‰) > SF (−29.2 ± 0.2‰) > LL (−29.6 ± 0.2‰) because of increasing leaching of C-isotopically light compounds. The higher δ13C values of DOM in SS15 (−27.8 ± 1.0‰), SS30 (−27.6 ± 1.1‰), and ST (−27.9 ± 1.1‰) than in the above-ground solutions suggested that roots and root exudates are major belowground DOM sources. Although in DOM the C/N ratios correlated with the δ13C values when all solutions were considered, this was not the case for SS15, SS30, and ST alone. Thus, the δ13C values of DOM provide an additional tool to assess the sources and turnover of DOM.
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Keywords: |
C/N ratio |
13C natural abundance |
Dissolved organic carbon |
Moses, J.; Peters, M.K.; Tiede, Y.; Mottl, O.; Donoso, D.A.; Farwig, N.; Fayle, T.M.; Novotny, V.; Sanders, N.J. & Klimes, P. (2023): Nutrient use by tropical ant communities varies among three extensive elevational gradients: A cross-continental comparison. Global Ecology and Biogeography n/a(n/a), -.
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DOI: 10.1111/geb.13757
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Resumen:
Resumen:
Abstract Aim Many studies demonstrate that climate limits invertebrates along tropical elevational gradients, but we have only a rudimentary understanding of the role of nutrient limitation and climatic seasonality. Here we examined the relationships between ant community structure, nutrient use and season along three undisturbed elevational gradients, each from a different continent. Location Ecuador (South America), Papua New Guinea (PNG: Oceania), Tanzania (Africa). Time period 2011–2014. Major taxa studied Ants. Methods Along each of the three gradients, we placed six distinct nutrient types (amino acid, sucrose, sucrose + amino acid, lipid, NaCl, H2O). In total, we distributed 2370 baits at 38 sites from 203 m to 3972 m. We used generalized linear models to test for the effects of elevation and season on ant species richness and activity and relative nutrient use. We also tested if changes in ant trophic guilds corresponded to changes in the use of particular nutrients. Results Both species richness and activity decreased with elevation along each gradient. However, there were significant interaction effects among elevation, region and season, as ant activity in the dry season was higher in Ecuador and Tanzania but lower in PNG. Relative nutrient use varied among regions: ant preference for some nutrients changed with increasing elevation in Ecuador (decrease in lipid use) and Tanzania (decrease in amino acid and H2O use), while season affected nutrient use in PNG. There were common trends in trophic guilds along the three elevational gradients (e.g. proportional increase of predators), but these did not explain most of the nutrient use patterns. Main conclusion While the structure of ant communities changed similarly with elevation, both the seasonal and elevational effects on nutrient use by ants differed between continents. We argue that regional differences in climate and nutrient availability rather than ant functional composition shape nutrient use by ants.
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Keywords: |
nutrient use |
Formicidae |
elevational gradients |
feeding preference |
foraging |
functional group |
intercontinental differences |
invertebrates |
seasonal shifts |
tropical forests |
Barczyk, M.; Acosta Rojas, D.C.; Espinosa, C.I.; Schleuning, M. & Neuschulz, E.L. (2023): Biotic pressures and environmental heterogeneity shape beta- diversity of seedling communities in tropical montane forests. Ecography e06538, 1-11.
Acosta Rojas, D.C.; Barczyk, M.; Espinosa, C.I.; Farwig, N.; Homeier, J.; Tiede, Y.; Velescu, A.; Tinoco, B.A.; Wilcke, W.; Neuschulz, E.L. & Schleuning, M. (2023): Abiotic factors similarly shape the distribution of fruit, seed and leaf traits in tropical fleshy-fruited tree communities. Acta Oecologica 121, 103953.
Acosta Rojas, D.C.; Barczyk, M.; Espinosa, C.I.; Tinoco, B.A.; Neuschulz, E.L. & Schleuning, M. (2023): Climate and microhabitat shape the prevalence of endozoochory in the seed rain of tropical montane forests. Biotropica 55, 408-417.
Knoke, T.; Hanley, N.; Roman-Cuesta, R.M.; Groom, B.; Venmans, F. & Paul, C. (2023): Trends in tropical forest loss and the social value of emission reductions. Nature Sustainability online, 1-15.
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DOI: 10.1038/s41893-023-01175-9
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Resumen:
Resumen:
Reducing global forest losses is essential to mitigate climate change and
its associated social costs. Multiple market and non-market factors can
enhance or reduce forest loss. Here, to understand the role of non-market
factors (for example, policies, climate anomalies or conflicts), we can
compare observed trends to a reference (expected) scenario that excludes
non-market factors. We define an expected scenario by simulating
land-use decisions solely driven by market prices, productivities and
presumably plausible decision-making. The land-use allocation model
considers economic profits and uncertainties as incentives for forest
conversion. We compare reference forest losses in Brazil, the Democratic
Republic of Congo and Indonesia (2000–2019) with observed forest
losses and assign differences from non-market factors. Our results
suggest that non-market factors temporarily lead to lower-than-expected
forest losses summing to 11.1 million hectares, but also to phases with
higher-than-expected forest losses of 11.3 million hectares. Phases with
lower-than-expected forest losses occurred earlier than those with
higher-than-expected forest losses. The damages avoided by delaying
emissions that would otherwise have occurred represent a social value
of US$61.6 billion (as of the year 2000). This result shows the economic
importance of forest conservation efforts in the tropics, even if reduced
forest loss might be temporary and reverse over time.
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Keywords: |
land use change |
land use modeling |
social costs of carbon |
Cornejo, X.; Homeier, J. & Ulloa, C. (2023): Heisteria austroecuadorica (Erythropalaceae): A new species from southeastern Ecuador. Phytotaxa 599(3), 201-206.
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DOI: 10.11646/phytotaxa.599.3.7
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Resumen:
Resumen:
Heisteria austroecuadorica, a new species of Erythropalaceae from the conserved evergreen montane forest at the San Francisco reserve, in southeastern Ecuador, is here described and illustrated. It is characterized by the flowers with 10 stamens, and relatively large fruits, with the apex conspicuously depressed, and the calyx not covering the base of the fruits.
Heisteria austroecuadorica is assessed provisionally as Endangered.
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Keywords: |
San Francisco |
montane forest |
Wurz, A.; Bendix, J.; Homeier, J.; Matt, F.; Paladines, P.; Serrano, F. & Farwig, N. (2023): A hidden gem in the Tumbesian dry forest in southern Ecuador: Estacon Cientfica Laipuna. ECOTROPICA 25(1/2), -.
Raffelsbauer, V.; Pucha-Cofrep, F.; Strobl, S.; Knüsting, J.; Schorsch, M.; Trachte, K.; Scheibe, R.; Bräuning, A.; Windhorst, D.; Bendix, J.; Silva, B. & Beck, E. (2023): Trees with anisohydric behavior as main drivers of nocturnal evapotranspiration in a tropical mountain rainforest. PloS ONE 18(3), 1-1.
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DOI: 10.1371/journal.pone.0282397
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Resumen:
Resumen:
This study addresses transpiration in a tropical evergreen mountain forest in the Ecuadorian
Andes from the leaf to the stand level, with emphasis on nocturnal plant-water relations. The
stand level: Evapotranspiration (ET) measured over 12 months with the Eddy-Covariance
(ECov) technique proved as the major share (79%) of water received from precipitation. Irre-
spective of the humid climate, the vegetation transpired day and night. On average, 15.3%
of the total daily ET were due to nocturnal transpiration. Short spells of drought increased
daily ET, mainly by enhanced nighttime transpiration. Following leaf transpiration rather
than air temperature and atmospheric water vapor deficit, ET showed its maximum already
in the morning hours. The tree level: Due to the humid climate, the total water consumption
of trees was generally low. Nevertheless, xylem sap flux measurements separated the
investigated tree species into a group showing relatively high and another one with low sap
flux rates. The leaf level: Transpiration rates of Tapirira guianensis, a member of the high-
flux-rate group, were more than twice those of Ocotea aciphylla, a representative of the
group showing low sap flux rates. Representatives of the Tapirira group operated at a rela-
tively high leaf water potential but with a considerable diurnal amplitude, while the leaves of
the Ocotea group showed low water potential and small diurnal fluctuations. Overall, the
Tapirira group performed anisohydrically and the Ocotea group isohydrically. Grouping of
the tree species by their water relations complied with the extents of the diurnal stem circum-
ference fluctuations. Nighttime transpiration and hydrological type: In contrast to the isohy-
drically performing trees of the Ocotea group, the anisohydric trees showed considerable
water vapour pressure deficit (VPD)-dependent nocturnal transpiration. Therefore, we con-
clude that nighttime ET at the forest level is mainly sourced by the tree species with aniso-
hydric performance.
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Keywords: |
dendrometer |
Evapotranspiration |
Sap flux |
Eddy covariance |
Knoke, T.; Gosling, E. & Reith, E. (2022): Understanding and modelling the ambiguous impact of off-farm income on tropical deforestation. Journal of Land Use Science 17, 1-20.
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DOI: 10.1080/1747423X.2022.2146220
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Resumen:
Resumen:
Few land-allocation models consider the impact of off-farm income on
tropical deforestation. We provide a concept to integrate off-farm income
in a mechanistic multiple-objective land-allocation model, while distinguishing
between farms with and without re-allocation of on-farm labor
to obtain off-farm income. On farms with re-allocation of labor we found
that off-farm income reduced farmers’ financial dependency on deforestation-
related agricultural income leading to less tropical deforestation.
The influence of off-farm income covered two aspects: availability of
additional income and re-allocation of on-farm labor to off-farm activities.
The labor effect tended to reduce deforestation slightly more than the
income effect. On farms without re-allocation of on-farm labor we showed
how farmers can use off-farm income to purchase additional labor to
accelerate deforestation. Our study highlights the importance of considering
off-farm income in land-use models to better understand, model
and possibly curb tropical deforestation.
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Keywords: |
land use change |
Husmann, K.; von Groß, V.; Bödeker, K.; Fuchs, J.; Paul, C. & Knoke, T. (2022): optimLanduse: A package for multiobjective land-cover composition optimization under uncertainty. Methods in Ecology and Evolution Online, 1-10.
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DOI: 10.1111/2041-210X.14000
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Resumen:
Resumen:
1. How to simultaneously combat biodiversity loss and maintain ecosystem functioning
while improving human welfare remains an open question. Optimization
approaches have proven helpful in revealing the trade-offs
between multiple
functions and goals provided by land-cover
configurations. The R package optim-
Landuse provides tools for easy and systematic applications of the robust multiobjective
land-cover
composition optimization approach of Knoke et al. (2016).
2. The package includes tools to determine the land-cover
composition that best
balances the multiple functions a landscape can provide, and tools for understanding
and visualizing the reasoning behind these compromises. A tutorial
based on a published dataset guides users through the application and highlights
possible use-cases.
3. Illustrating the consequences of alternative ecosystem functions on the theoretically
optimal landscape composition provides easily interpretable information
for landscape modelling and decision-making.
4. The package opens the approach of Knoke et al. (2016) to the community of
landscape modellers and planners and provides opportunities for straightforward
systematic or batch applications.
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Keywords: |
models of land-use/land-cover change |
multicriteria assessment |
robust optimization |
Zuidema, P.A.; Babst, F.; Groenendijk, P.; Trouet, V.; Abiyu, A.; Acuana-Soto, R.; Adenesky-Filho, E.; Alfaro-Sanchez, R.; Aragao, J.R.V.; Assis-Pereira, G.; Bai, X.; Barbosa, A.C.; Battipaglia, G.; Beeckman, H.; Botosso, P.C.; Bradley, T.; Bräuning, A.; Brienen, R.; Buckley, B.M.; Camarero, J.J.; Carvalho, A.; Ceccantini, G.; Centeno-Erguera, L.R.; Cerano-Paredes, J.; Chavez-Duran, A.A.; Cintra, B.B.L.; Cleaveland, M.K.; Couralet, C.; Arrigo, R.D.; Valle, J.I.; Dünisch, O.; Enquist, B.J.; Esemann-Quadros, K.; Eshetu, Z.; Fan, Z.; Ferrero, M.E.; Fichtler, E.; Fontana, C.; Francisco, K.S.; Gebrekirstos, A.; Gloor, E.; Granato-Souza, D.; Haneca, K.; Harley, G.L.; Heinrich, I.; Helle, G.; Inga, J.G.; Islam, M.; Jiang, Y.; Kaib, M.; Khamisi, Z.H.; Koprowski, M.; Kruijt, B.; Layme, E.; Leemans, R.; Leffler, A.J.; Lisi, C.S.; Loader, N.J.; Locosselli, G.M.; Lopez, L.; Lopez-Hernandez, M.I.; Lousada, J.L.P.C.; Mendivelso, H.A.; Mokria, M.; Montoia, V.R.; Moors, E.; Nabais, C.; Ngoma, J.; de Junior, F.C.N.; Oliveira, J.M.; Olmedo, G.M.; Pagotto, M.A.; Panthi, S.; Perez-De-Lis, G.; Pucha-Cofrep, D.; Pumijumnong, N.; Rahman, M.; Ramírez Correa, J.A.; Requena-Rojas, E.J.; de Ribeiro, A.S.; Robertson, I.; Roig, F.A.; Rubio-Camacho, E.A.; Sass-Klaassen, U.; Schöngart, J.; Sheppard, P.R.; Slotta, F.; Speer, J.H.; Therrell, M.D.; Toirambe, B.; Tomazello-Filho, M.; Torbenson, M.C.A.; Touchan, R.; Venegas-Gonzalez, A.; Villalba, R.; Villanueva-Diaz, J.; Vinya, R.; Vlam, M.; Wils, T. & Zhou, Z. (2022): Tropical tree growth driven by dry-season climate variability. Nature Geoscience 15, pages 269–276.
Pierick, K.; Leuschner, C.; Link, R.; Baez, S.; Velescu, A.; Wilcke, W. & Homeier, J. (2024): Above-and belowground strategies of tropical montane tree species are coordinated and driven by small-scale nitrogen availability. Functional Ecology X(X), X-Y.
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DOI: 10.1111/1365-2435.14554
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Resumen:
Resumen:
1. The question whether the strategies of above-and belowground plant organs
are coordinated as predicted by the plant economics spectrum theory is still
under debate. We aim to determine the leading dimensions of tree trait variation
for above-and belowground functional traits, and test whether they represent
spectra of adaptation along a soil fertility gradient in tropical Andean
forests.
2. We measured leaf, stem and fine root functional traits, and individual-level
soil nutrient availability for 433 trees from 52 species at three elevations between
1000 and 3000 m a.s.l.
3. We found close coordination between above– and belowground functional traits
related to the trade-off between resource acquisition and conservation, whereas
root diameter and specific root length formed an independent axis of covarying
traits. The position of a tree species along the acquisition–conservation axis of
the trait space was closely associated with local soil nitrogen, but not phosphorus,
availability.
4. Our results imply that above-and belowground plant functional traits determine
at which edaphic microhabitats coexisting tree species can grow, which is potentially
crucial for understanding community assembly in species-rich
tropical montane forests.
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Keywords: |
Ecuador |
tropical montane forest |
fine roots |
intraspecific variability |
functional traits |
Pierick, K.; Link, R.; Leuschner, C. & Homeier, J. (2022): Elevational trends of tree fine root traits in species-rich tropical Andean forests. Oikos x(x), x-x.
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DOI: 10.1111/oik.08975
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Resumen:
Resumen:
With increasing elevation, trees in tropical montane forests have to invest larger frac-tions of their resources into their fine roots in order to compensate for increasingly unfavorable soil conditions. It is unclear how elevation and related edaphic changes influence the variability in tree fine root traits and belowground functional diversity. We measured six fine root traits related to resource acquisition on absorptive fine roots of 288 trees from 145 species along an elevational gradient from 1000 m to 3000 m a.s.l. in tropical montane forests of the Ecuadorian Andes. We analyzed trait relation-ships with elevation and soil nutrient availability, and tested whether root functional diversity varied along these gradients. Fine roots at higher elevations and at more nutrient-poor sites were thicker, had higher tissue densities, and lower specific root length and nutrient concentrations than at lower elevations. These trends were diluted by the coexistence of tree species with a broad range of different root traits within communities particularly towards lower elevations, where root functional diversity was significantly higher. We conclude that nutrient limitation and potentially further adverse conditions at higher elevations are strong environmental filters that lead to trait convergence towards a conservative resource use strategy, whereas different trait syndromes are equally successful at lower elevations.
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Keywords: |
Ecuador |
tropical montane forest |
fine roots |
elevational gradient |
functional traits |
Báez, S.; Fadrique, B.; Feeley, K. & Homeier, J. (2022): Changes in tree functional composition across topographic gradients and through time in a tropical montane forest. PLOS ONE 17(4), e0263508.
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DOI: 10.1371/journal. pone.0263508
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Resumen:
Resumen:
Understanding variation in tree functional traits along topographic gradients and through time provides insights into the processes that will shape community composition and determine ecosystem functioning. In montane environments, complex topography is known to affect forest structure and composition, yet its role in determining trait composition, indices on community climatic tolerances, and responses to changing environmental conditions has not been fully explored. This study investigates how functional trait composition (characterized as community-weighted moments) and community climatic indices vary for the tree community as a whole and for its separate demographic components (i.e., dying, surviving, recruiting trees) over eight years in a topographically complex tropical Andean forest in southern Ecuador. We identified a strong influence of topography on functional composition and on species’ climatic optima, such that communities at lower topographic positions were dominated by acquisitive species adapted to both warmer and wetter conditions compared to communities at upper topographic positions which were dominated by conservative cold adapted species, possibly due to differences in soil conditions and hydrology. Forest functional and climatic composition remained stable through time; and we found limited evidence for trait-based responses to environmental change among demographic groups. Our findings confirm that fine-scale environmental conditions are a critical factor structuring plant communities in tropical forests, and suggest that slow environmental warming and community-based processes may promote short-term community functional stability. This study highlights the need to explore how diverse aspects of community trait composition vary in tropical montane forests, and to further investigate thresholds of forest response to environmental change.
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Keywords: |
Ecuador |
forest dynamics |
environmental change |
plant functional traits |
tropical montane forests (TMF) |
topography |
Knoke, T.; Gosling, E.; Reith, E.; Gerique, A.; Pohle, P.; Valle-Carrión, L.A.; Ochoa Moreno, S.; Castro, L.M.; Calvas, B.; Hildebrandt, P.; Döllerer, M.; Bastit, F. & Paul, C. (2022): Confronting sustainable intensification with uncertainty and extreme values on smallholder tropical farms. Sustainability Science 0, 1-18.
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DOI: 10.1007/s11625-022-01133-y
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Resumen:
Resumen:
Sustainable intensification of agricultural lands might reconcile the conservation of tropical forest with food production,but in-depth assessments considering uncertainty and extreme values are missing. Uncertainty prohibits mapping probabilities to potential future states or ranking these states in terms of their likelihood. This in turn hampers the assessment of possible decision outcomes. Here, we use simulations to investigate how uncertainty may influence the social acceptability of alternative land-use strategies to halt tropical deforestation (including sustainable intensification), based on indicators representing farmer satisfaction. The results show how extreme values (worst values) for indicators of farmer satisfaction
may undermine the adoption of sustainable intensification. We demonstrate that a pure forest conservation strategy leads to lower food production, but outperforms a sustainable intensification strategy that maintains food security. Pure forest conservation performed better, i.e., could secure higher farmer satisfaction, than sustainable intensification across a range of indicator groups. This suggests strong barriers to achieving sustainable intensification. Using agricultural subsidies breaks the dominance of pure forest conservation by enhancing the economic returns of sustainable intensification. We discuss the
importance of access to labor and farmers’ preferences for the use of already cleared lands, which achieved the worst values under sustainable intensification and conclude that any assessment of land-use strategies requires careful consideration of uncertainty and extreme values.
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Keywords: |
deforestation |
land use change |
sustainable land use |
agriculture |
land use modeling |
intensification |
Weigand, A.; Homeier, J.; Lehnert, M. & Kessler, M. (2022): Influence of increasing nutrient availability on fern and lycophyte diversity. American Fern Journal 112(1), 17-35.
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DOI: 10.1640/0002-8444-112.1.17
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Resumen:
Resumen:
Increased nutrient supply can have drastic effects on natural ecosystems, especially in
naturally nutrient-poor ones such as most tropical rainforests. Many studies have focused on the reaction of trees to fertilization, but little is known about herbaceous plants. Ferns are a particularly common group in tropical forests, spanning all vegetation types and zones. Here, we assess how seven years of moderate addition of nitrogen (N), phosphorus (P), and N+P along an elevational gradient (1000–3000 m) have impacted richness and composition of fern and lycophyte assemblages in tropical montane rain forests growing on naturally nutrient deficient soils in the Ecuadorian Andes. We found that fertilization does not affect overall species richness, but that there were strong differences in species abundances (~60% of species), both negative and positive, that were apparently related to the systematic affiliations and ecological properties of the affected species. These diverse responses of ferns to fertilization provide insight into the sensitivity and complexity of the relationships of nutrient availability and community composition in tropical forests.
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Keywords: |
NUMEX |
diversity |
Andes |
tropical montane forest |
elevational gradient |
experimental nutrient addition |
fern |
Ostertag, R.; Restrepo, C.; Dalling, J.W.; Martin, P.H.; Abiem, I.; Aiba, S.; Alvarez-Dávila, E.; Aragón, R.; Ataroff, M.; Chapman, H.; Cueva, A.; Fadrique, B.; Fernández, R.D.; González, G.; Gotsch, S.G.; Häger, A.; Homeier, J.; Iñiguez-Armijos, C.; Llambi, L.D.; Moore, G.W.; Næsborg, R.R.; Poma López, L.N.; Vieira Pompeu, P.; Powell, J.R.; Ramírez Correa, J.A.; Scharnagl, K.; Tobón, C. & Williams, C.B. (2021): Litter decomposition rates across tropical montane and lowland forests are controlled foremost by climate. Biotropica 54(2), 309-326.
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DOI: 10.1111/btp.13044
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Resumen:
Resumen:
The “hierarchy of factors” hypothesis states that decomposition rates are controlled primarily by climatic, followed by biological and soil variables. Tropical montane forests (TMF) are globally important ecosystems, yet there have been limited efforts to provide a biome-scale characterization of litter decomposition. We designed a common litter decomposition experiment replicated in 23 tropical montane sites across the Americas, Asia, and Africa and combined these results with a previous study of 23 sites in tropical lowland forests (TLF). Specifically, we investigated (1) spatial heterogeneity
in decomposition, (2) the relative importance of biological factors that affect leaf and wood decomposition in TMF, and (3) the role of climate in determining leaf litter decomposition rates within and across the TMF and TLF biomes. Litterbags of two mesh sizes containing Laurus nobilis leaves or birchwood popsicle sticks were spatially dispersed and incubated in TMF sites, for 3 and 7 months on the soil surface and at 10–15 cm depth. The within-site
replication demonstrated spatial variability in mass loss. Within TMF, litter type was the predominant biological factor influencing decomposition (leaves > wood), with mesh and burial effects playing a minor role.
When comparing across TMF and TLF, climate was the predominant control over decomposition,but the Yasso07 global model (based on mean annual temperature and precipitation) only modestly predicted decomposition rate. Differences in controlling factors between biomes suggest that TMF, with their high rates of carbon storage, must be explicitly considered when developing theory and models to elucidate carbon cycling rates in the tropics.
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Keywords: |
climate |
decomposition |
tropical montane forests (TMF) |
Muñoz, P.; Orellana-Alvear, J.; Bendix, J.; Feyen, J. & Celleri, R. (2021): Flood Early Warning Systems Using Machine Learning Techniques: The Case of the Tomebamba Catchment at the Southern Andes of Ecuador. Hydrology 8(4), -.
Wallis, C.; Tiede, Y.; Beck, E.; Boehning-Gaese, K.; Brandl, R.; Donoso, D.A.; Espinosa, C.; Fries, A.; Homeier, J.; Inclan, D.; Leuschner, C.; Maraun, M.; Mikolajewski, K.; Neuschulz, E.L.; Scheu, S.; Schleuning, M.; Suárez, J.P.; Tinoco, B.A.; Farwig, N. & Bendix, J. (2021): Biodiversity and ecosystem functions depend on environmental conditions and resources rather than the geodiversity of a tropical biodiversity hotspot. Scientific Reports 11(1), 24530.
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DOI: 10.1038/s41598-021-03488-1
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Resumen:
Resumen:
Biodiversity and ecosystem functions are highly threatened by global change. It has been proposed that geodiversity can be used as an easy-to-measure surrogate of biodiversity to guide conservation management. However, so far, there is mixed evidence to what extent geodiversity can predict biodiversity and ecosystem functions at the regional scale relevant for conservation planning. Here, we analyse how geodiversity computed as a compound index is suited to predict the diversity of four taxa and associated ecosystem functions in a tropical mountain hotspot of biodiversity and compare the results with the predictive power of environmental conditions and resources (climate, habitat, soil). We show that combinations of these environmental variables better explain species diversity and ecosystem functions than a geodiversity index and identified climate variables as more important predictors than habitat and soil variables, although the best predictors differ between taxa and functions. We conclude that a compound geodiversity index cannot be used as a single surrogate predictor for species diversity and ecosystem functions in tropical mountain rain forest ecosystems and is thus little suited to facilitate conservation management at the regional scale. Instead, both the selection and the combination of environmental variables are essential to guide conservation efforts to safeguard biodiversity and ecosystem functions.
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Keywords: |
Biodiversity |
geodiversity |
Fiedler, K. & Brehm, G. (2021): Aposematic Coloration of Moths Decreases Strongly along an Elevational Gradient in the Andes. Insects 12(10), -.
Cueva, A.; Manchego, C.; Bastidas, C. & Curto, M. (2021): Development and characterization of microsatellite markers for two subspecies of Handroanthus chrysanthus. Rodriguésia 72(e00722020), 6.
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DOI: 10.1590/2175-7860202172088
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Resumen:
Resumen:
An understanding of the genetic diversity and structure of plant species is essential in order to comprehend the degree of biodiversity loss and to develop successful restoration programs. Handroanthus is an important genus that presents one of the most valuable timbers of South America. Handroanthus chrysanthus is an important species distributed in Central and South America. Microsatellite markers are not previously developed for this species. Ten microsatellites for Handroanthus chrysanthus developed using high-throughput sequencing are presented here. The usefulness of these microsatellite loci for the genetic analysis of subspecies H. chrysanthus subsp. chrysanthus (distributed in coastal dry forests) and subspecies H. chrysanthus subsp. meridionalis (distributed in premontane moist forests) is analyzed. At least eight polymorphic microsatellites are useful for each subspecies, seven of which can be used in both subspecies.
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Keywords: |
Ecuador |
dry forest |
Handroanthus chrysanthus |
Guayacan |
microsatellites |
premontane forest |
subspecies |