Search results for "rainforest"
showing 10 items of 85 documents
A global perspective on the climate‐driven growth synchrony of neighbouring trees
2020
2 .pdf files: File 1. Author's article final version, Post-Print (19 Pags.- 4 Figs.- 2 Tabls.). File 2. Supplementary Materials (3 Figs.- 2 Tabls.- 1 Model Equation).
Neolithic Human Societies and Woodlands in the North-Western Mediterranean Region: Wood and Charcoal Analysis
2017
An overview of woodland history in the north-western Mediterranean region, based on charcoal analysis (Anthracology) from Mesolithic and Neolithic sites, is proposed for the Mediterranean areas of France, Spain and Portugal. The taxonomic identification of charcoal fragments and the diachronic variations of taxa frequencies provide, for each settlement, an accurate image of the local vegetal cover. During the end of the last glaciation, beginning of the Holocene, vegetation dynamics reflects the evolution of climatic and geographic conditions. Any potential ecological impact by hunter-fisher-gatherer communities (Mesolithic) remains invisible; the same comment applies to the farming-herding…
Seed dispersal by ants: are seed preferences influenced by foraging strategies or historical constraints?
2003
Summary The objective of this study was to quantify preferences of ants for seeds of different plant species and to test if these preferences were caused by foraging strategies or by historical constraints. We compared seed removal rates of ten different ant-dispersed plant species found in temperate forests, along forest edges and in grassland. We found significant differences in seed removal rates among the ten species. To test if these differences were caused by foraging strategies we examined the relationship between seed and elaiosome size and seed removal rate. We found that seeds with larger elaiosomes had significantly higher removal rates. To test the historical constraint hypothes…
Vindication of Ulota pygmaeothecia (Orthotrichaceae, Bryophyta)
2017
Ulota pygmaeothecia (Müll.Hal.) Kindb. and Ulota luteola (Hook.f. & Wilson) Wijk & Margad. are two epiphytic mosses from the evergreen Magellanic rainforests of southern South America. Both mosses have been considered as distinct species since their original description, with their specific status retained following the comprehensive review by Nicolajs Malta of South American Ulota (1927). Recently the synonymization of U. pygmaeothecia and U. luteola was proposed (Wang & Jia 2016), based mainly on the similarities stated in the protologues and the study of the available type specimens of U. pygmaeothecia and U. fulvella, as the type materials of U. luteola were lost in the mail…
El futuro del derecho como lucha contra la idolatría tecnológica
2019
The main challenge that Law will have to face in the near future is the defense of human being against the uncontrolled power of technology in different spheres: ecology versus the becoming of a new geological age: the Anthropocene; the finances, versus speculation and taxes fraud; biolaw, versus the transhumanist challenge; the rights to privacy and no manipulation versus GAF( Google, Amazon, Facebook). El reto principal al que debera hacer frente el derecho en el futuro es la defensa del ser humano frente al poder incontrolado de la tecnologia en diferentes campos: la ecologia, frente a la aparicion de una nueva era geologica: el Antropoceno; las finanzas, frente a la especulacion y el fr…
Assessing the role of megafauna in tropical forest ecosystems and biogeochemical cycles - the potential of vegetation models
2018
21 pages; International audience; Megafauna (terrestrial vertebrate herbivores > 5 kg) can have disproportionate direct and indirect effects on forest structure, function, and biogeochemical cycles. We reviewed the literature investigating these effects on tropical forest dynamics and biogeochemical cycles in relation to ecology, paleoecology, and vegetation modelling. We highlight the limitations of field‐based studies in evaluating the long‐term consequences of loss of megafauna. These limitations are due to inherent space‐time restrictions of field‐studies and a research focus on seed dispersal services provided by large animals. We further present evidence of a research gap concerning t…
An annotated checklist of freshwater Copepoda (Crustacea, Hexanauplia) from continental Ecuador and the Galapagos Archipelago.
2019
An annotated checklist of the free-living freshwater Copepoda recorded in different regions in Ecuador (including the Amazon, the Andes, the coastal region, and the Galapagos Islands) is here provided. We revised all published records, critically evaluated the validity of each taxon and provided short taxonomic and biogeographical remarks for each one. A total of 27 taxa have been reported, including species and records at the generic level only. The species and taxa identified only up to the generic level belong to five families and 14 genera. The Cyclopoida is the most diverse group with 16 records belonging to species (or identified to the generic level only) and eight genera, followed b…
The role of ENSO flavours and TNA on recent droughts over Amazon forests and the Northeast Brazil region
2019
Amazon tropical forests and the semiarid Northeast Brazil (NEB) region have registered very severe droughts during the last two decades, with a frequency that may have exceeded natural climate variability. Severe droughts impact the physiological response of Amazon forests, decreasing the availability to absorb atmospheric CO2, as well as biodiversity and increasing risk of fires. Droughts on this region also affect population by isolating them due to anomalous low river levels. Impacts of droughts over NEB region are related to water and energy security and subsistence agriculture. Most drought episodes over Amazonia and NEB are associated with El Nino (EN) events, anomalous warming over t…
Natural Forest Management in Neotropical Mountain Rain Forests — An Ecological Experiment
2008
In tropical forests, the first step in the destruction cycle is usually the over-exploitation of high value timber, leading not only to extinction of the extracted species (Silva Matos and Bovi 2002) but also to the conversion of the forests into pastures in many cases (Wunder 1996b). In many highlands of Ecuador the productivity of the pastures is depleted due to the invasion of bracken fern (see Chapter 28 in this volume), which finally leads again to the conversion of primary forests by local farmers (Paulsch et al. 2001; Hartig and Beck 2003). This process usually is accompanied by loss of biodiversity (Brooks et al. 200 I), increased erosion, changes of hydrology (Bruijnzel 2004), and …
Seasonal and Inter-annual Variation of Evapotranspiration in Amazonia Based on Precipitation, River Discharge and Gravity Anomaly Data
2019
We analyzed seasonal and spatial variations of evapotranspiration (ET) for five Amazon sub-basins and their response to the 2015/16 El Nino episode using a recently developed water-budget approach. ET varied typically between similar to 7 and 10 cm/month with exception of the Xingu basin for which it varied between 10 and 15 cm/month. Outstanding features of ET seasonality are (i) generally weak seasonality, (ii) two ET peaks for the two very wet catchments Solimoes and Negro, with one occurring during the wet season and one during the drier season, and (iii) a steady increase of ET during the second half of the dry season for the three drier catchments (Madeira, Tapajos, Xingu). Peak ET oc…