Palm Swamp Research Articles

A Late Quaternary palynological record of a palm swamp in the Cerrado of central Brazil interpreted using modern analog data

The fossil pollen record from a Late Quaternary peat core collected in the São José palm swamp, in the northwest region of Minas Gerais state (Central Brazil), is interpreted using a dataset of modern pollen spectra as modern analogs. Principal component analysis and dissimilarity coefficients were used to compare fossil and modern samples, supporting the interpretation of past environmental dynamics. The results suggest that at ca. 15,700 and ca. 15,400calyearsBP, the buriti (Mauritia flexuosa) palm (that characterizes the palm swamps today) was absent and the climate was colder. Around 15,200calyearsBP, the increasing occurrence of buriti and the development of the Cerrado stricto sensu, a savanna woodland, indicate a warmer climate. At the end of the Late Pleistocene and during the Pleistocene-Holocene transition, the palm swamp central zone expanded and a dense Cerrado stricto sensu developed, suggesting a warm and humid climate. By the end of the Early Holocene, a much drier climate is suggested by the shrinkage of the palm swamp and a more open regional vegetation. Subsequently, and until ca. 4400calyearsBP, a wetter climate is indicated by the extended central zone of the São José palm swamp that reached a maximum expansion at ca. 6500calyearsBP. After 3500calyearsBP, the predominance of the Campo Sujo, a herbaceous-shrubby vegetation, indicates the return of relatively dry conditions. In the last two millennia, a decrease in the extent of the humid zone of the palm swamp suggests an intensification of drier conditions. Lower precipitation inferred at the end of the Holocene, and the predominantly humid conditions in the Middle Holocene, is different from the general pattern observed in southern and western Cerrado sites, but is in agreement with paleoclimate data from Northeastern Brazil.

Seasonal variability in methane and nitrous oxide fluxes from tropical peatlands in the western Amazon basin

Abstract. The Amazon plays a critical role in global atmospheric budgets of methane (CH4) and nitrous oxide (N2O). However, while we have a relatively good understanding of the continental-scale flux of these greenhouse gases (GHGs), one of the key gaps in knowledge is the specific contribution of peatland ecosystems to the regional budgets of these GHGs. Here we report CH4 and N2O fluxes from lowland tropical peatlands in the Pastaza–Marañón foreland basin (PMFB) in Peru, one of the largest peatland complexes in the Amazon basin. The goal of this research was to quantify the range and magnitude of CH4 and N2O fluxes from this region, assess seasonal trends in trace gas exchange, and determine the role of different environmental variables in driving GHG flux. Trace gas fluxes were determined from the most numerically dominant peatland vegetation types in the region: forested vegetation, forested (short pole) vegetation, Mauritia flexuosa-dominated palm swamp, and mixed palm swamp. Data were collected in both wet and dry seasons over the course of four field campaigns from 2012 to 2014. Diffusive CH4 emissions averaged 36.05 ± 3.09 mg CH4–C m−2 day−1 across the entire dataset, with diffusive CH4 flux varying significantly among vegetation types and between seasons. Net ebullition of CH4 averaged 973.3 ± 161.4 mg CH4–C m−2 day−1 and did not vary significantly among vegetation types or between seasons. Diffusive CH4 flux was greatest for mixed palm swamp (52.0 ± 16.0 mg CH4–C m−2 day−1), followed by M. flexuosa palm swamp (36.7 ± 3.9 mg CH4–C m−2 day−1), forested (short pole) vegetation (31.6 ± 6.6 mg CH4–C m−2 day−1), and forested vegetation (29.8 ± 10.0 mg CH4–C m−2 day−1). Diffusive CH4 flux also showed marked seasonality, with divergent seasonal patterns among ecosystems. Forested vegetation and mixed palm swamp showed significantly higher dry season (47.2 ± 5.4 mg CH4–C m−2 day−1 and 85.5 ± 26.4 mg CH4–C m−2 day−1, respectively) compared to wet season emissions (6.8 ± 1.0 mg CH4–C m−2 day−1 and 5.2 ± 2.7 mg CH4–C m−2 day−1, respectively). In contrast, forested (short pole) vegetation and M. flexuosa palm swamp showed the opposite trend, with dry season flux of 9.6 ± 2.6 and 25.5 ± 2.9 mg CH4–C m−2 day−1, respectively, versus wet season flux of 103.4 ± 13.6 and 53.4 ± 9.8 mg CH4–C m−2 day−1, respectively. These divergent seasonal trends may be linked to very high water tables (> 1 m) in forested vegetation and mixed palm swamp during the wet season, which may have constrained CH4 transport across the soil–atmosphere interface. Diffusive N2O flux was very low (0.70 ± 0.34 µg N2O–N m−2 day−1) and did not vary significantly among ecosystems or between seasons. We conclude that peatlands in the PMFB are large and regionally significant sources of atmospheric CH4 that need to be better accounted for in regional emissions inventories. In contrast, N2O flux was negligible, suggesting that this region does not make a significant contribution to regional atmospheric budgets of N2O. The divergent seasonal pattern in CH4 flux among vegetation types challenges our underlying assumptions of the controls on CH4 flux in tropical peatlands and emphasizes the need for more process-based measurements during periods of high water table.

Assessment of geostatistical features for object-based image classification of contrasted landscape vegetation cover

Accurate mapping and monitoring of savanna and semiarid woodland biomes are needed to support the selection of areas of conservation, to provide sustainable land use, and to improve the understanding of vegetation. The potential of geostatistical features, derived from medium spatial resolution satellite imagery, to characterize contrasted landscape vegetation cover and improve object-based image classification is studied. The study site in Brazil includes cerrado sensu stricto, deciduous forest, and palm swamp vegetation cover. Sentinel 2 and Landsat 8 images were acquired and divided into objects, for each of which a semivariogram was calculated using near-infrared (NIR) and normalized difference vegetation index (NDVI) to extract the set of geostatistical features. The features selected by principal component analysis were used as input data to train a random forest algorithm. Tests were conducted, combining spectral and geostatistical features. Change detection evaluation was performed using a confusion matrix and its accuracies. The semivariogram curves were efficient to characterize spatial heterogeneity, with similar results using NIR and NDVI from Sentinel 2 and Landsat 8. Accuracy was significantly greater when combining geostatistical features with spectral data, suggesting that this method can improve image classification results.

Characterizing degradation of palm swamp peatlands from space and on the ground: An exploratory study in the Peruvian Amazon

Peru has the fourth largest area of peatlands in the Tropics. Its most representative land cover on peat is a Mauritia flexuosa dominated palm swamp (thereafter called dense PS), which has been under human pressure over decades due to the high demand for the M. flexuosa fruit often collected by cutting down the entire palm. Degradation of these carbon dense forests can substantially affect emissions of greenhouse gases and contribute to climate change. The first objective of this research was to assess the impact of dense PS degradation on forest structure and biomass carbon stocks. The second one was to explore the potential of mapping the distribution of dense PS with different degradation levels using remote sensing data and methods. Biomass stocks were measured in 0.25ha plots established in areas of dense PS with low (n=2 plots), medium (n=2) and high degradation (n=4). We combined field and remote sensing data from the satellites Landsat TM and ALOS/PALSAR to discriminate between areas typifying dense PS with low, medium and high degradation and terra firme, restinga and mixed PS (not M. flexuosa dominated) forests. For this we used a Random Forest machine learning classification algorithm. Results suggest a shift in forest composition from palm to woody tree dominated forest following degradation. We also found that human intervention in dense PS translates into significant reductions in tree carbon stocks with initial (above and below-ground) biomass stocks (135.4±4.8MgCha−1) decreased by 11 and 17% following medium and high degradation. The remote sensing analysis indicates a high separability between dense PS with low degradation from all other categories. Dense PS with medium and high degradation were highly separable from most categories except for restinga forests and mixed PS. Results also showed that data from both active and passive remote sensing sensors are important for the mapping of dense PS degradation. Overall land cover classification accuracy was high (91%). Results from this pilot analysis are encouraging to further explore the use of remote sensing data and methods for monitoring dense PS degradation at broader scales in the Peruvian Amazon. Providing precise estimates on the spatial extent of dense PS degradation and on biomass and peat derived emissions is required for assessing national emissions from forest degradation in Peru and is essential for supporting initiatives aiming at reducing degradation activities.

Reconstituição paleoambiental da Vereda Carrasco da Raposa, Parque Estadual da Serra do Cabral, MG, Brasil, por meio de estudos palinológico e isotópico

A análise palinológica e de isótopos estáveis (C e N) dos sedimentos da Vereda Carrasco da Raposa (VCR) permitiu a reconstituição paleoambiental dos últimos 21.000 anos AP na região do Parque Estadual da Serra do Cabral (PESC), MG, Brasil. Os resultados mostraram que durante a influência do Último Máximo Glacial, entre 21.150 e 18.850 anos cal. AP, as condições climáticas na Serra do Cabral eram mais frias e com menor umidade do que as atuais; entre 18.850 e 3.550 anos cal. AP o clima passou a ser mais quente e com maior umidade; a partir de 1.650 anos cal. AP houve o estabelecimento da vereda, em condições semelhantes e/ou comparáveis às atuais. Quanto às mudanças fitofisionômicas, foi observada uma sucessão da vegetação com predomínio de Formações Campestres do Cerrado associadas a traços de Formações Florestais na base, Campo Sujo Úmido e Campo Rupestre associados a elementos de mata típicos do Cerrado na porção mediana do perfil; em direção ao topo a partir de 1.650 anos cal. AP houve a instalação da vereda, com a ocorrência dos buritis (Mauritia flexuosa). Os dados isotópicos de C e N indicaram que entre 21.150 e 6.500 anos cal. AP havia uma provável mistura de plantas C3 e C4 como fonte da matéria orgânica sedimentar, mas com o predomínio de plantas C3, com valores de δ13C entre ~-24‰ e -21,5‰. Os valores de C/N (1,5 a 11,5) indicaram o predomínio de fitoplâncton e os valores de δ15N (3,5‰ a ~1,0‰) evidenciaram a mistura de algas e plantas terrestres. Em torno de 3.550 anos cal. AP até o presente a diminuição nos valores de C/N (1,5 a ~6) confirmou um ambiente alagado e com maior influência algal na composição da matéria orgânica sedimentar.

Ranas del género Pipa (Anura: Pipidae) de la Orinoquia colombiana: nuevos registros y comentarios sobre su taxonomía, distribución e historia natural

Two sympatric species of aquatic frogs (Pipa pipa and Pipa snethlageae) are reported for the first time for the Bita and Orinoco rivers in the moriche palm swamp streams of the floodplain, in the department of Vichada, Colombia. Updated maps are provided with the extension of the range of these two species, comments on their taxonomy and some aspects of their natural history are described.

FIRE MANAGEMENT IN VEREDAS (PALM SWAMPS): NEW PERSPECTIVES ON TRADITIONAL FARMING SYSTEMS IN JALAPÃO, BRAZIL

Abstract The veredas (palm swamps) of the cerrado biome are legally protected as Áreas de Preservação Permanente (Permanent Preservation Areas), and the use of fire in these wetlands is prohibited. We carried out a preliminary assessment of environmental impacts of the local use of agricultural fire in veredas through a collaborative research project in Jalapão (Tocantins, Brazil). We found that "roças de esgoto" (drained peat swamp swidden fields) form the basis of the agricultural system of this region. These fields ensure production throughout the year, provide more income than "roças de toco" (rainfed swidden fields), and may function as a repository of agrobiodiversity on a regional scale. This study suggests that the use of fire in veredas associated with roças de esgoto does not lead to significant deforestation, that is, to the disappearance of the forest physiognomy, but instead helps maintain tree cover during the fallow period, possibly accelerating natural succession.

Veredas da região sudeste: peculiaridades florísticas e estruturais e situação de conservação

The Mauritia flexuosa L. f. (Arecaceae) palm swamps (known as veredas in Brazil) are hygrophilous communities associated with hydromorphic soils in areas of headwaters, and feature special importance for water and biodiversity maintenance in the Cerrado biome. In northern Minas Gerais, the veredas have more complex structure and floristic composition in comparison with the veredas located in other parts of central Brazil, in the same biome. However, these areas are less studied and suffering various environmental impacts, which can uncharacterize them even before they are properly known. In the present work, a literature review was carried out, in which the age and the development of vegetation in the veredas of central Brazil and north of Minas Gerais were addressed. The conservation status and the importance of these areas for the biome were also discussed. Hence it was concluded that the veredas of the north of Minas Gerais are older than the veredas of central Brazil, suggesting that they are in a more advanced stage of ecological succession. However, many factors can influence the floristic composition and structure of these plant communities, requiring further studies involving ecological processes in veredas in order to elucidate those matters. Keywords: vegetational structure, ecological succession, palynological analysis.

A new species of Platycarpum (Rubiaceae, Henriquezieae) from Peruvian Amazon

The new species Platycarpum loretensis (Rubiaceae) is endemic to the Loreto Department, Peru, and restricted to white sand forests (varillal), palm swamps, and peatlands. It is similar to P. orinocense from which can be separated by the oblanceolate leaves with prominulous intersecondary veins (vs. elliptic to ovate, without intersecondary veins), corollas 1.9–3 cm long (vs. 1.2–2(–2.2) cm long), and fruits 4.7–5.5 × 3.6–4.9 cm (vs. 3–3.5 × 2.8–3.5 cm).

Palinologia da Vereda Juquinha/Cuba, Parque Estadual da Serra do Cabral, Minas Gerais, Brasil

Organic sediments rich in palynomorphs, as the ones studied in Juquinha/Cuba palm swamp, in Serra do Cabral, Minas Gerais State, can be an important proxy to reconstruct paleoenvironment evolution. This study presents the qualitative and quantitative pollen analysis of 35 stratigraphic levels from a core sample of 400 cm length corresponding to the last ~18.500 years cal. BP. Regarding to the climatic changes a colder and wetter climate was registered between ~18.500 and ~8.250 years cal. BP and a wetter climate with increase in temperatures from ~7.800 years cal. BP to the present days. Three diff erent intervals called JCI, JCII e JCIII were established based on palynological changes along the core: interval JCI, with colder and wetter climatic conditions, between ~18.500 and ~8.250 years cal. BP recording Podocarpus, Drimys brasiliensis, Eryngium, Hydrocotyle and Peperonia taxa; interval JCII, from ~7.100 to ~2.900 years cal. BP, with the increase in humidity, temperature and taxa diversity and the fi rst occurrence of Mauritia fl exuosa at ~4.200 years cal. BP, the palm swamp in these interval was surrounded by a mosaic of Cerrado (broad sense) and forests; interval JCIII, with higher humidity conditions such as JCII conditions but with palm swamp expansion and mosaic of Cerrado (broad sense) and forests decrease.

STRUCTURE OF NATURAL REGENERATION IN RELATION TO SOIL PROPERTIES AND DISTURBANCE IN TWO SWAMP FORESTS

ABSTRACT Veredas (palm swamps) is a type of vegetation associated with watercourses, characterized by the presence of Mauritia flexuosa palm trees. These systems are not well understood and suffer from high anthropogenic pressure. The aims of this study were to describe the natural regeneration of two swamp forests in vereda systems with different anthropogenic impacts and investigate if the variation in these plant communities are associated to edaphic conditions. The study was performed in preserved and impacted sites located in the Environmental Protection Area of the Pandeiros River in northern Minas Gerais. At each site, one hundred 25 m2 plots were established for surveying regenerating shrubs and trees (≥1 cm diameter at the base of the stem and < 3 cm diameter at breast height). Vegetation structure was evaluated by phytosociological parameters, similarity index, and size distribution of individuals. Regenerating strata was correlated with chemical and physical soil analyses. The vegetation at the preserved site was characterized by a higher number of individuals and a lower diversity but contained species that were typical of flooded areas. The results also showed differences in soil nutrient availability between sites that influenced the distribution of species at the two study sites.

Seed germination of Microlicia fasciculata, an apomictic and aluminium accumulator species: Unexpected intraspecific variability in a restricted Neotropical savanna area

In the Ecological Station of Panga, Microlicia fasciculata (Melastomataceae) is restricted to areas with palm swamps, environments subjected to desiccation due to anthropogenic actions including global climate change. This can put the species at risk of local extinction. Studies related to seed germination of M. fasciculata are rare and could help in understanding its ability to survive in these environments. The present paper aims to (1) assess intraspecific variability of seed germination and (2) study the effect of aluminium on seed germination. Two experiments were conducted in completely randomized design. The first evaluated intraspecific variability based on the germination measurements. The second evaluated the effect of aluminium on seed germination (5, 20, 40, 80 and 160mgL−1 Al(OH)3 at pH 4.0 and one aluminium-free treatment at pH 7.0). The results showed high intraspecific variability for germinability (6–30%), coefficient of variation of germination time (5.2–29.6%) and uncertainty (0.92–2.59bits). Seed germination was slow (0.08≤v¯≤0.11day−1; v¯ for quick species is 1day−1 or some hours−1) and asynchronous (0.11≤Z≤0.38; perfect synchrony is equal to 1). These features guarantee the survival of the species in these unstable environments, especially in relation to the volume of water that accumulates in the rainy season and its decrease in the dry season or by anthropogenic action. Under the action of aluminium and pH 4.0 the germinability of seeds ranged from 5.5 to 9.5% for doses between 5 and 160mgL−1 of Al(OH)3, whereas in the aluminium-free treatment at pH 7.0 germinability reached 19%. Our hypothesis is that the presence of aluminium in the seeds, since the species is an accumulator (4000–6000mg Alkg−1 in leaves), is sufficient to trigger the germination process and the external addition was a limiting factor for the seeds.

The odonata community of a brazilian vereda: seasonal patterns, species diversity and rarity in a palm swamp environment

Studies concerning the occurrence of species and seasonality are of great importance for both the elucidation of species distribution and conservation of natural habitats. We performed a survey of Odonata species and studied their seasonality in an endemic endangered palm swamp (i.e. Veredas) environment of the Ecological Reserve of Clube de Caca e Pesca Itororo de Uberlândia, Southestern Brazil. Between July 2010 and June 2011, we recorded 31 species of five different families and 21 genera. The community was strongly seasonal, since 24 species occurred in the wet season, while ten occurred in both dry and wet season, and only two species occured only in the dry season. All Anisoptera species preferred lentic habitats, whereas seven of the 18 Zygopera species preferred lentic habitats and 11 species preferred lotic sites. The five Calopterygidae and Protoneuridae species preferred lotic habitats. The study site exhibits a great diversity of dragonflies and damselflies, which are important elements of the trophic chain in the Cerrado aquatic and neighboring land environments. This justifies the development of conservation actions in palm swamp areas, which are poorly known and threatened by the constant advance of urban, monoculture and pasture areas in Cerrado.

Modern pollen spectra of the Cerrado vegetation in two national parks of Central Brazil, and implications for interpreting fossil pollen records

Twenty four surface samples were collected for palynological analysis from different environments in the Cerrado biome, which extends over a vast area in Central Brazil. These samples were used to investigate the relationship between vegetation and pollen spectra in the Cerrado and, thereby, contribute to a more precise interpretation of fossil pollen records from this region, particularly those collected on palm swamps. Pollen grains from the phytophysiognomy that surrounds the palm swamp generally occur in low percentages in surface samples, whereas local plants are very abundant in the pollen spectra. Although local taxa tend to predominate, two aspects of the landscape may be reconstructed from the pollen spectra using numerical methods: the local environment of the deposition site and the surrounding regional vegetation. Using PCA and dissimilarity coefficient analysis, a group of seventeen taxa and a group of fourteen arboreal taxa are proposed as those that provide improved results when investigating the local environment and regional vegetation, respectively. Because herbaceous taxa are very abundant in the palm swamps, an analysis of the content of arboreal taxa in the pollen spectra is more appropriate for reconstructing the openness of the regional vegetation.

Structure and biodiversity of zooplankton communities in freshwater habitats of a Vereda Wetland Region, Minas Gerais, Brazil

Abstract Aims: Vereda wetlands are among the most important aquatic habitats in Brazilian savannah (Cerrado) because of their association with river springs and its relevancy for biodiversity conservation. This study aimed to determine and compare the biodiversity of zooplankton in vereda lakes, differentiated by the presence or absence of aquatic macrophytes at an environmental reserve in Uberlândia, Minas Geais, Southeastern Brazil. Zooplanctonic abundance patterns and their relation with environmental parameters were also discussed and presented through multivariate statistics. Methods Twelve samples were taken at water surface, at 15-day intervals in 2006. It was observed a total richness of 75 species, including 12 genera, 29 species and one sub-species as new records for Minas Gerais State. Results Rotifers were the predominant group and Lecanidae was the most diverse family. Among cladocerans, Chydoridae showed the greatest richness and Bosminidae the highest abundance. Few adult copepods were sampled in this study, but nauplii were very frequent. Cyclopidae was the most common family among copepods and there was no record of Calanoida. Conclusions The difference in composition among the studied lakes was remarkable. The lake with macrophytes showed the greatest richness but the lowest density, and the opposite situation occurred in the other lake. This can be explained by the fact that aquatic macrophytes, as primary producers, exert a bottom-up effect on zooplankton community, sustaining a high local diversity in contrast with a low numeric abundance of these microorganisms. Therefore, this pattern may have been created by the surround heterogeneity and, at the same time, by the reduction of available minerals of the system caused by macrophyte matter fixation. Many studies on zooplankton need to be developed in palm swamp communities in order to better comprehend the biological diversity and the energy balance in different habitats for the conservation of aquatic ecosystems.

Contributions of local floodplain resources to livelihoods and household income in the Peruvian Amazon

This paper highlights the economic contributions of natural resources to rural livelihoods and represents one of the first comprehensive income quantifications assessing household- and landscape-level determinants of resource use in the Amazon. Income data (n=176) collected over one year quantified all subsistence and cash income generated by indigenous and non-indigenous residents in two locations within the Ampiyacu–Apayacu basin. Products harvested from unmanaged forests and agroforests contributed 42% of household income, while fishing contributed 14%, resulting in over 55% of household income derived from local resources. Poorer households are most reliant on forest products, particularly low value resources, while wealthier households benefit more from commercial harvest. Tobit regression analyses and general linearized models identified key determinants of (i) resource harvest engagement and (ii) absolute and relative incomes derived from natural resources. Basin location (East versus West), ethnic identification, distance to market/forest proximity, household wealth and access to non-farm/forest cash income sources were all significant. These determinants varied, however, depending on the specific resource harvested (e.g. palm heart versus timber). This relates to i) varying abundance of individual resources across the landscape, and ii) differences in harvest purpose (subsistence versus sale) and product type (low-value/low-return versus high-value/high return). Future policies and initiatives should promote the conservation and sustainable use of diverse environments which are critical to livelihoods (e.g., forests, palm swamps, agroforests, rivers and lakes).

Effects of past climate variability on fire and vegetation in the cerrãdo savanna of the Huanchaca Mesetta, NE Bolivia

Abstract. Cerrãdo savannas have the greatest fire activity of all major global land-cover types and play a significant role in the global carbon cycle. During the 21st century, temperatures are projected to increase by ~ 3 °C coupled with a precipitation decrease of ~ 20%. Although these conditions could potentially intensify drought stress, it is unknown how that might alter vegetation composition and fire regimes. To assess how Neotropical savannas responded to past climate changes, a 14 500-year, high-resolution, sedimentary record from Huanchaca Mesetta, a palm swamp located in the cerrãdo savanna in northeastern Bolivia, was analyzed with phytoliths, stable isotopes, and charcoal. A non-analogue, cold-adapted vegetation community dominated the Lateglacial–early Holocene period (14 500–9000 cal yr BP, which included trees and C3 Pooideae and C4 Panicoideae grasses. The Lateglacial vegetation was fire-sensitive and fire activity during this period was low, likely responding to fuel availability and limitation. Although similar vegetation characterized the early Holocene, the warming conditions associated with the onset of the Holocene led to an initial increase in fire activity. Huanchaca Mesetta became increasingly fire-dependent during the middle Holocene with the expansion of C4 fire-adapted grasses. However, as warm, dry conditions, characterized by increased length and severity of the dry season, continued, fuel availability decreased. The establishment of the modern palm swamp vegetation occurred at 5000 cal yr BP. Edaphic factors are the first-order control on vegetation on the rocky quartzite mesetta. Where soils are sufficiently thick, climate is the second-order control of vegetation on the mesetta. The presence of the modern palm swamp is attributed to two factors: (1) increased precipitation that increased water table levels and (2) decreased frequency and duration of surazos (cold wind incursions from Patagonia) leading to increased temperature minima. Natural (soil, climate, fire) drivers rather than anthropogenic drivers control the vegetation and fire activity at Huanchaca Mesetta. Thus the cerrãdo savanna ecosystem of the Huanchaca Plateau has exhibited ecosystem resilience to major climatic changes in both temperature and precipitation since the Lateglacial period.

Grado de cobertura del muestreo de escarabajos coprófagos (Coleoptera: Scarabaeidae: Scarabaeinae) en Colombia

Una de las principales limitantes para generar estrategias para la conservación, es la falta de información y la dificultad para identificar vacíos de conocimiento, que faciliten el entendimiento de un grupo taxonómico. En este trabajo desarrollamos el diagnóstico sobre el grado de cobertura del muestreo de escarabajos coprófagos en Colombia. Se recopiló la bibliografía, utilizando 12 bases de datos y se revisaron 16 940 especímenes depositados en 26 colecciones. Se encontraron 232 especies, en 386 localidades, con un porcentaje de cobertura del 10.62%. Se evidencia en los últimos años un incremento en el número de estudios, sin embargo solo 64 localidades tienen publicaciones. Se encontraron registros para todos los departamentos, siendo los mejor muestreados: Cundinamarca, Antioquia, Valle del Cauca y Boyaca. Los ecosistemas con mayor número de publicaciones son el bosque húmedo premontano Andino, el bosque húmedo montano Andino y el bosque húmedo del Pacífico. Sin embargo, existen muchos ecosistemas con muy pocos estudios como los manglares, zonas desérticas, savanas naturales, morichales, paramos, bosques inundables y sistemas agrícolas. La región biogeográfica con mayor número de localidades es la Andina, seguida del Chocó-Magdalenense y la Amazonía. A nivel general, persiste un alto nivel de submuestreo. Se evidencia la necesidad de ampliar la cobertura del muestreo a nivel nacional, enfocando los esfuerzos en aquellas áreas submuestreadas con importancia a nivel de conservación. Jorge Ari Noriega1, Edgar Camero R.2, Jorge Arias-Buriticá3, Luis Carlos Pardo4, José Mauricio Montes5, Aldemar A. Acevedo6, Andrea Esparza7, Betselene Murcia Ordóñez8, Hector Garcia9 & Cesil Solís10 1Laboratorio de Zoología y Ecología Acuática - LAZOEA, Universidad de Los Andes, Bogotá, Colombia; jnorieg@hotmail.com2Departamento de Biología, Universidad Nacional de Colombia, Bogotá, Colombia; eecameror@unal.edu.co3Universidad Nacional de Colombia, Bogotá, Colombia; joaariasbu@unal.edu.co4Instituto de Investigaciones Ambientales del Pacífico-IIAP-MMA, regional Valle, Palmira, Colombia; pardolc@hotmail.com5Universidad Nacional de Colombia, Medellín, Colombia; jmpamplonman@gmail.com6Grupo de Ecología y Biogeografía, Facultad de Ciencias Básicas, Universidad de Pamplona, Pamplona, Colombia; bioaldemar@gmail.com7Universidad Industrial de Santander, Bucaramanga, Colombia; aesparzaleon@gmail.com8Grupo BYDA, Universidad de la Amazonía, Florencia, Colombia; b.murcia@udla.edu.co9Herbario UTMC, Universidad del Magdalena, Santa Marta, Colombia; coleopterocoprofago@yahoo.es10Universidad del Atlántico, Fundación Hidrobiológica George Dahl, Barranquilla, Colombia; cesilsoli@yahoo.com

VARIAÇÃO BIOMÉTRICA DE DIÁSPOROS DE BURITI (<i>Mauritia flexuosa</i> L.f. – ARECACEAE) EM VEREDAS EM DIFERENTES ESTÁGIOS DE CONSERVAÇÃO

http://dx.doi.org/10.5902/1980509816583As veredas são fitofisionomias do bioma Cerrado, onde, no estrato arbóreo, predomina a palmeira arbórea Mauritia flexuosa L.f. - buriti, espécie considerada recurso-chave para muitos animais, que a utilizam como moradia e fonte alimentar, e também pelo próprio homem, que usa suas folhas e frutos como matéria-prima e alimento. Apesar de ocorrerem em ambientes protegidos pela legislação ambiental, ações antrópicas nas veredas têm afetado as populações do buriti, por meio da diminuição do número de indivíduos ocasionada por desmatamento, assoreamento e drenagem dessas áreas. O objetivo desse trabalho foi avaliar a morfometria de frutos e sementes de buriti oriundos de seis veredas em diferentes estágios de conservação, situadas na Área de Proteção Ambiental do Rio Pandeiros (norte de Minas Gerais). Foram amostrados, no total, 1800 frutos e sementes, que foram mensurados em comprimento, largura, espessura e peso. Para detectar diferenças das medidas morfométricas dos frutos e das sementes entre as áreas de coleta foi feita a análise de variância. Foram observadas variações nas medidas morfométricas de frutos e sementes entre as áreas de estudo, sendo que 87,5% das maiores médias ocorreram em áreas com menores intervenções antrópicas. Esse fato, possivelmente, está relacionado aos impactos ocorridos nas veredas, além das variações genéticas que podem incidir sobre os indivíduos.

Vegetational Diversity and its Change Dynamics in Indian Sundarbans

Sunderban, the mangroves in the Ganga-Brahmaputra-Meghna delta shared between India and Bangladesh are the largest coastal wetland system, well known for their floral diversity. Vegetation survey and analysis was carried out at 42 forest sites randomly selected in Sundarban to record 30 species of mangrove plants belonging to 18 families. Change dynamics of mangrove forests was also studied taking Champion and Seth (1968) forest type classification as a baseline to record striking changes in forest composition. Significant changes were observed in vegetation composition at sites previously demarcated under a particular sub-type. Palm swamp with predominantly Phoenix paludosa have converted into mangrove scrub with mixed species composition. Some new species have emerged in pure mangrove forest (4B/TS2) which has acquired character of salt water mixed forest (Heretiera). These composition and structure changes of Sundarban forests may be attributed climatic change and anthropogenic pressure.