Tropical Forests of the Lowlands

2007 ◽  
Author(s):  
Peter A. Furley
Keyword(s):  
Tropical Forests ◽  
Amazon Basin ◽  
Drainage Basin ◽  
Deciduous Forest ◽  
Evergreen Forest ◽  
Lowland Forest ◽  
Atmospheric Circulation Patterns ◽  
Alexander Von Humboldt ◽  
Dry Deciduous Forest ◽  
The Tropics

Most of South America lies within the tropics, and lowland tropical ecosystems make up the majority of its landscapes. Although there is great concern for the Amazon ecosystem, the largest of the world’s tropical forests, there are many other fascinating and in some cases more endangered types of lowland forest. Such forests may be defined as lying below 1,000 m above sea level, although it is difficult to set arbitrary limits (Hartshorn, 2001). The two main lowland moist evergreen forests are the Hylea (a term coined by Alexander von Humboldt to denote rain forests of the Amazon Basin) and the much smaller Chocó forest on the Pacific coast between Panama and Ecuador. Two related yet distinctive types of forest are the Mata Atlântica or Atlantic moist evergreen forest and the Mata Decidua or dry deciduous forest, including the caatinga woodland, which is both deciduous and xerophytic (Rizzini et al., 1988). The latter two formations are among the most threatened of all South American forests. Lowland forests vary from dense and multilayered to open and single-layered, from evergreen to deciduous, and from flooded or semi-aquatic to near-arid. Tree heights range from 30 to 40 m with emergent trees reaching over 50 m, to forests where the tallest trees barely attain 20 m (Harcourt and Sayer, 1996; Solorzano, 2001). However, because of its extent and importance, Amazonia will form the principal focus of this chapter. Amazonia covers a vast area (>6 × 106 km2) and contains some 60% of the world’s remaining tropical forest. The Amazon and Orinoco basins influence not only regional climates and air masses, but also atmospheric circulation patterns both north and south of the Equator. The sheer size and diversity of Amazonia exhausts a normal repertoire of grandiose adjectives. The Amazon may or may not be the longest river in the world but it is by far the greatest in terms of discharge, sending around one fifth of the world’s fresh water carried by rivers to the oceans(see chapter 5; Eden, 1990; Sioli, 1984). The drainage basin is twice as large as any other of the world’s catchments.

Wood Specific Gravity in Species from Two Tropical Forests in Mexico

IAWA Journal ◽  
1987 ◽  
Vol 8 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Josefina Barajas-Morales
Keyword(s):  
Specific Gravity ◽  
Tropical Forests ◽  
Tropical Rainforest ◽  
Deciduous Forest ◽  
Woody Species ◽  
T Test ◽  
Tropical Deciduous Forest ◽  
Wood Specific Gravity ◽  
Dry Deciduous Forest

The specific gravity of 220 woody species, half of them from a tropical rainforest, half from a tropical deciduous forest was measured. The two groups were compared using a Student t-test. The results show highly significant differences in specific gravity between the species from the two areas: woods from the dry deciduous forest tend to be much heavier than those from the rainforest.

The Atmospheric Component of Biogeochemical Cycles in the Amazon Basin

2001 ◽  
Author(s):  
Paulo Artaxo
Keyword(s):  
Land Use ◽  
Tropical Forests ◽  
Amazon Basin ◽  
Aerosol Particles ◽  
Trace Gases ◽  
Biogeochemical Cycles ◽  
Dry Season ◽  
Earth System ◽  
The Earth ◽  
The Tropics

Tropical forests, with their high biological activity, have the potential to emit large amounts of trace gases and aerosol particles to the atmosphere. The accelerated development and land clearing that is occurring in large areas of the Amazon basin suggest that anthropogenic effects on natural biogeochemical cycles are already occurring (Gash et al. 1996). The atmosphere plays a key role in this process. The tropics are the part of the globe with the most rapidly growing population, the most dramatic industrial expansion and the most rapid and pervasive change in land use and land cover. Also the tropics contain the largest standing stocks of terrestrial vegetation and have the highest rates of photosynthesis and respiration. It is likely that changes in tropical land use will have a profound impact on the global atmosphere (Andreae 1998, Andreae and Crutzen 1997). A significant fraction of nutrients are transported or dislocated through the atmosphere in the form of trace gases, aerosol particles, and rainwater (Keller et al. 1991). Also the global effects of carbon dioxide, methane, nitrous oxide, and other trace gases have in the forest ecosystems a key partner. The large emissions of isoprene, terpenes, and many other volatile organic compounds could impact carbon cycling and the production of secondary aerosol particles over the Amazon region. Vegetation is a natural source of many types of aerosol particles that play an important role in the radiation budget over large areas (Artaxo et al. 1998). There are 5 major reservoirs in the Earth system: atmosphere, biosphere (vegetation, animals), soils, hydrosphere (oceans, lakes, rivers, groundwater), and the lithosphere (Earth crust). Elemental cycles of carbon, oxygen, nitrogen, sulfur, phosphorus, and other elements interact with the different reservoirs of the Earth system. The carbon cycle has important aspects in tropical forests due to the large amount of carbon stored in the tropical forests and the high rate of tropical deforestation (Jacob 1999). In Amazonia there are two very different atmospheric conditions: the wet season (mostly from November to June) and the dry season (July-October) (see Marengo and Nobre, this volume). Biomass burning emissions dominate completely the atmospheric concentrations over large areas of the Amazon basin during the dry season (Artaxo et al. 1988).

scholarly journals A comparison between time-constrained counts and line transects as methods to estimate butterfly diversity in tropical habitats

2021 ◽  
Author(s):  
Suman Attiwilli ◽  
Nitin Ravikanthachari ◽  
Krushnamegh Kunte
Keyword(s):  
Species Richness ◽  
Deciduous Forest ◽  
Biodiversity Loss ◽  
Evergreen Forest ◽  
Population Declines ◽  
Butterfly Diversity ◽  
Dry Deciduous Forest ◽  
Feasible Alternative ◽  
Line Transects ◽  
Species Richness And Abundance

Long-term monitoring programmes have revealed catastrophic population declines that are contributing to biodiversity loss. These discoveries and the underlying programmes have been possible because of standardised methods of counting butterflies. Butterflies have been monitored using modified line transects, known in butterfly monitoring schemes as Pollard walks. However, line transects are not feasible in many tropical and mountainous habitats. To tackle this problem, we devised time-constrained (30-min) counts and compared butterfly diversity as estimated through this method with that estimated through line transects (500 m, 10 min) in three tropical habitats in India (evergreen forest, dry deciduous forest and an urban woodland). We tested the efficacy of the two methods to sample species richness and abundance, as well as numbers of rare, endemic and specialist butterflies. We observed greater species richness, and more species of habitat specialists and endemics per sample in time-constrained counts when compared with line transects in evergreen forest, but not in the other two habitats. Thus, time-constrained counts were more efficient at detecting species than line transects in the species-rich evergreen habitat. Apart from this difference, the two sampling methods captured similar levels of species richness and other measures of diversity. Time-constrained counts may thus be viewed as a feasible alternative to line transects to carry out butterfly surveys in tropical and mountainous landscapes. This method is particularly suited for biodiversity assessments and mapping involving citizen science initiatives, which has considerable potential in populous and tech-ready countries such as India.

Multi-year eddy covariance measurements of net ecosystem exchange in tropical dry deciduous forest of India

2021 ◽  
Vol 301-302 ◽  
pp. 108351
Author(s):  
Suraj Reddy Rodda ◽  
Kiran Chand Thumaty ◽  
MSS Praveen ◽  
Chandra Shekhar Jha ◽  
Vinay Kumar Dadhwal
Keyword(s):  
Eddy Covariance ◽  
Deciduous Forest ◽  
Net Ecosystem Exchange ◽  
Dry Deciduous Forest ◽  
Eddy Covariance Measurements

A new species of Lophopogon (Poaceae) from Ananthapuramu of Andhra Pradesh, India

Phytotaxa ◽  
2021 ◽  
Vol 500 (3) ◽  
pp. 234-240
Author(s):  
KOTHAREDDY PRASAD ◽  
NAGARAJU SIDDABATHULA ◽  
ANGAJALA NARAYANA SWAMY ◽  
ARAVEETI MADHUSUDHANA REDDY ◽  
MUDADLA SANKARA RAO ◽  
...  
Keyword(s):  
New Species ◽  
Andhra Pradesh ◽  
Deciduous Forest ◽  
Taxonomic Key ◽  
Dry Deciduous Forest ◽  
A New Species

A new species of Lophopogon (Poaceae), L. prasannae is described from dry deciduous forest of Ananthapuramu district, Andhra Pradesh, India. This new species shows morphological similarities with L. tridentatus and L. kingii but differs in certain characters, which are discussed below. A detailed description, photographs and taxonomic key are provided for easy identification of the species.

scholarly journals Molecular edge effects in the Endangered golden-brown mouse lemur Microcebus ravelobensis

Oryx ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 716-726 ◽  
Author(s):  
U. Radespiel ◽  
J. Schulte ◽  
R. J. Burke ◽  
S. M. Lehman
Keyword(s):  
Edge Effects ◽  
Deciduous Forest ◽  
Mitochondrial Control Region ◽  
Mouse Lemur ◽  
Continuous Forest ◽  
Ecological Changes ◽  
Close Proximity ◽  
Geographical Distances ◽  
Dry Deciduous Forest ◽  
Underlying Mechanisms

AbstractHabitat fragmentation creates habitat edges, and ecological edge effects can cause major changes in the ecology and distribution of many taxa. However, these ecological changes may in turn influence animal movements and lead to molecular edge effects and edge-related genetic structure, matters that are largely unexplored. This study aims to infer molecular edge effects and to test three possible underlying mechanisms in the Endangered golden-brown mouse lemur Microcebus ravelobensis, a nocturnal species in the dry deciduous forest of the Ankarafantsika National Park in north-western Madagascar. Mouse lemurs were sampled in one edge and two interior habitats in close proximity to each other (500–1,400 m) in a continuous forest. A total of 41 mouse lemur samples were genotyped with seven nuclear microsatellites, and a fragment of the mitochondrial control region was sequenced for all samples. The overall genetic diversity (allelic richness, heterozygosity, haplotype richness, nucleotide diversity) was lower in the edge habitat compared to the two interior sites and all subpopulations showed signals of relatively low genetic exchange and significant genetic differentiation between them despite the short geographical distances, supporting the local preference model. These findings can be interpreted as preliminary signals of a molecular edge effect and suggest the potential for local adaptation. They are highly relevant for the conservation of fragmented populations, because a further subdivision of already small populations may increase their vulnerability to stochastic demographic changes and collapse.

scholarly journals Madrigueras de Liomys pictus en dos selvas tropicales del Pacífico mexicano.

2009 ◽  
Vol 13 (1) ◽  
pp. 63 ◽  
Author(s):  
Yolanda Domínguez-Castellanos ◽  
Beatriz Hernandez Meza ◽  
Angeles Mendoza D. ◽  
Gerardo Ceballos González
Keyword(s):  
Seed Production ◽  
Tropical Forests ◽  
Plant Species ◽  
Deciduous Forest ◽  
Vegetation Type ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Mexican Pacific ◽  
La Selva

Resumen: Se determinó la estructura y el contenido de las madrigueras de Liomys pictus por tipo de vegetación y temporada del año, en dos selvas tropicales del Pacífico Mexicano. Se encontraron 24 madrigueras: en la selva baja la mayoría son complejas, mientras que  en la selva mediana son lineales, por consiguiente y de acuerdo a la clasificación de las madrigueras, en selva baja se presentaron madrigueras múltiples y en selva mediana madrigueras simples. De acuerdo al contenido, las de selva baja tienen en promedio una mayor cantidad de materiales en comparación a las de selva mediana. Se catalogaron un total de 248 especies de plantas de estas 50 se comparten en ambos sitios, del total de las especies se llegaron a identificar sólo 77. Las familias más representativas fueron Leguminoseae, Euphorbiaceae y Convolvulaceae. La estructura de las madrigueras no esta determinada por la temporalidad, sin embargo el contenido esta determinado con la cantidad de material almacenado aunque la producción de semillas esta definido por el patrón de fructificación que esta dado a lo largo del año.Palabras clave: Madrigueras, estructura, contenido, Liomys pictus, Jalisco, México.Abstract: We determined the structure and contents of burrows of Liomys pictus by vegetation type and season in two tropical forests of the Mexican Pacific. 24 burrows were found in the tropical dry forest and most complex, in the semi deciduous forest is linear, and therefore according to the classification of the burrows in the tropical dry forest are more numerous and simple in the semi deciduous forest. According to the content, of the tropical dry forest have on average a greater amount of material compared to the semi deciduous forest. Were categorized a total of 248 plant species of these 50 sites are shared in both the total number of species is to determine 77. The most representative families were Leguminoseae, Euphorbiaceae and Convulvolaceae. The structure of the burrows is not affected by the timing, but the content is determined with the amount of stored material but seed production is defined by the pattern of fruit that is given throughout the year.Key words: Burrows, structure, food hoarding, Liomys pictus, Jalisco, Mexico.

scholarly journals EVALUATION OF THE PERFORMANCE OF SAR AND SAR-OPTICAL FUSED DATASET FOR CROP DISCRIMINATION

2019 ◽  
Vol XLII-3/W6 ◽  
pp. 563-571
Author(s):  
S. Mustak ◽  
G. Uday ◽  
B. Ramesh ◽  
B. Praveen
Keyword(s):  
Land Use ◽  
Deciduous Forest ◽  
Accuracy Assessment ◽  
Parameter Tuning ◽  
Northern Region ◽  
Evergreen Forest ◽  
Support Vector ◽  
Cropping Pattern ◽  
Land Use Classification ◽  
Crop Discrimination

<p><strong>Abstract.</strong> Crop discrimination and acreage play a vital role in interpreting the cropping pattern, statistics of the produce and market value of each product. Sultan Battery is an area where a large amount of irrigated and rainfed paddy crops are grown along with Rubber, Arecanut and Coconut. In addition, the northern region of Sultan Battery is covered with evergreen and deciduous forest. In this study, the main objective is to evaluate the performance of optical and Synthetic Aperture Radar (SAR)-optical hybrid fusion imageries for crop discrimination in Sultan Bathery Taluk of Wayanad district in Kerala. Seven land use classes such as paddy, rubber, coconut, deciduous forest, evergreen forest, water bodies and others land use (e.g., built-up, barren etc.) were selected based on literature review and local land use classification policy. Both Sentinel-2A (optical) and sentinel-1A (SAR) satellite imageries of 2017 for Kharif season were used for classification using three machine learning classifiers such as Support Vector Machine (SVM), Random Forest (RF) and Classification and Regression Trees (CART). Further, the performance of these techniques was also compared in order to select the best classifier. In addition, spectral indices and textural matrices (NDVI, GLCM) were extracted from the image and best features were selected using the sequential feature selection approach. Thus, 10-fold cross-validation was employed for parameter tuning of such classifiers to select best hyperparameters to improve the classification accuracy. Finally, best features, best hyperparameters were used for final classification and accuracy assessment. The results show that SVM outperforms the RF and CART and similarly, Optical+SAR datasets outperforms the optical and SAR satellite imageries. This study is very supportive for the earth observation scientists to support promising guideline to the agricultural scientist, policy-makers and local government for sustainable agriculture practice.</p>

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