Search results for "rainforest"
showing 10 items of 85 documents
A Lexicon-based Approach for Sentiment Classification of Amazon Books Reviews in Italian Language
2016
We present a system aimed at the automatic classification of the sentiment orientation expressed into book reviews written in Italian language. The system we have developed is found on a lexicon-based approach and uses NLP techniques in order to take into account the linguistic relation between terms in the analyzed texts. The classification of a review is based on the average sentiment strenght of its sentences, while the classification of each sentence is obtained through a parsing process inspecting, for each term, a window of previous items to detect particular combinations of elements giving inversions or variations of polarity. The score of a single word depends on all the associated …
Nutrient Additions Affecting Matter Turnover in Forest and Pasture Ecosystems
2013
Nutrient inputs into ecosystems of the tropical mountain rainforest region are projected to further increase in the next decades. To investigate whether important ecosystem services such as nutrient cycling and matter turnover in native forests and pasture ecosystems show different patterns of response, two nutrient addition experiments have been established: NUMEX in the forest and FERPAST at the pasture. Both ecosystems already responded 1.5 years after the start of nutrient application (N, P, NP, Ca). Interestingly, most nutrients remained in the respective systems. While the pasture grass was co-limited by N and P, most tree species responded to P addition. Soil microbial biomass in the…
Black and brown carbon over central Amazonia: long-term aerosol measurements at the ATTO site
2018
The Amazon rainforest is a sensitive ecosystem experiencing the combined pressures of progressing deforestation and climate change. Its atmospheric conditions oscillate between biogenic and biomass burning (BB) dominated states. The Amazon further represents one of the few remaining continental places where the atmosphere approaches pristine conditions during occasional wet season episodes. The Amazon Tall Tower Observatory (ATTO) has been established in central Amazonia to investigate the complex interactions between the rainforest ecosystem and the atmosphere. Physical and chemical aerosol properties have been analyzed continuously since 2012. This paper provides an in-depth analysis of t…
Influx of African biomass burning aerosol during the Amazonian dry season through layered transatlantic transport of black carbon-rich smoke
2020
Black carbon (BC) aerosols influence the Earth's atmosphere and climate, but their microphysical properties, spatiotemporal distribution, and long-range transport are not well constrained. This study presents airborne observations of the transatlantic transport of BC-rich African biomass burning (BB) smoke into the Amazon Basin using a Single Particle Soot Photometer (SP2) as well as several complementary techniques. We base our results on observations of aerosols and trace gases off the Brazilian coast onboard the HALO (High Altitude and LOng range) research aircraft during the ACRIDICON-CHUVA campaign in September 2014. During flight AC19 over land and ocean at the northeastern coastline …
Comparison of Different Techniques for the Measurement of Precipitation in Tropical Montane Rain Forest Regions
2007
Abstract Characteristics of different precipitation measurements in a tropical mountain valley in southern Ecuador are compared in this study to determine potential errors. The instruments are used for different ecological purposes like erosion studies, through fall measurements, investigation of atmospheric chemistry, and modeling of area rainfall distribution. Five recording devices (two precipitation radars, an electro-optical present weather sensor, and two tipping buckets) and three totaling gauges were operated in parallel at a designated site. Data were taken between 1998 and 2003 with different temporal resolution and different operational periods. The general agreement between the …
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…
Ecotourism in Bolivia : an ethnographical study of ecotourism impacts in Madidi National Park
2016
Master thesis development management - University of Agder 2016 The concepts of ecotourism are widely defined but it is often used as a marketing instrument in order to promote tourism businesses related to nature. Ecotourism experience a fast growth in world tourism industry and many developing countries are trying to use ecotourism as a tool to achieve sustainable development. Ecotourism provides many beneficiaries to local environments, economies and socio-cultural lives. However, ecotourism may as well have harmful effects on those involved. Still, ecotourism conserves and protects local areas and its people. Madidi National Park in Bolivia has been estimated to be one of the world’s mo…
Amazonian biomass burning-derived acid and nutrient deposition in the north Andean montane forest of Ecuador
2008
[1] We explored the influence of biomass burning in Amazonia and northeastern Latin America on N, C, P, S, K, Ca, Mg, Al, Mn, and Zn cycles of an Andean montane forest in south Ecuador exposed to the Amazon basin between May 1998 and April 2003. We assessed the response of the element budget of three microcatchments (8–13 ha) to the variations in atmospheric deposition between the intensive burning season and outside the burning season in Amazonia. There were significantly elevated H, N, and Mn depositions during biomass burning. Elevated H deposition during biomass burning caused elevated base metal loss from the canopy and the organic horizon and deteriorated already low base metal supply…
Spatial throughfall heterogeneity in a montane rain forest in Ecuador: Extent, temporal stability and drivers
2009
Summary The drivers of spatial throughfall heterogeneity are still not fully understood. At an undisturbed forest site in the Ecuadorian Andes with ca. 2600 mm of annual rainfall we determined the accuracy of throughfall measurements by comparing Hellmann-type funnel gauges with troughs. At the same undisturbed and a managed, selectively-logged forest site we determined spatial variability of throughfall, temporal stability of spatial variability and the controls of spatial throughfall variability using a 4-year dataset in weekly resolution. There were no systematic differences between the collected volumes of funnel gauges and troughs. Based on the statistical distribution of annual throug…
Specialization and interaction strength in a tropical plant–frugivore network differ among forest strata
2011
The degree of interdependence and potential for shared coevolutionary history of frugivorous animals and fleshy-fruited plants are contentious topics. Recently, network analyses revealed that mutualistic relationships between fleshy-fruited plants and frugivores are mostly built upon generalized associations. However, little is known about the determinants of network structure, especially from tropical forests where plants' dependence on animal seed dispersal is particularly high. Here, we present an in-depth analysis of specialization and interaction strength in a plant-frugivore network from a Kenyan rain forest. We recorded fruit removal from 33 plant species in different forest strata (…