Spatial Impacts of Stream and Wetland Restoration on Riparian Soil Properties in the North Carolina Piedmont

Hydric soil development of riparian wetlands is primarily influenced by the hydrologic connection between the floodplains and the stream channel. Often, the goal of riparian restoration is to revitalize this connectivity through a restructuring of the stream channel and the floodplain; however, the effects of this restructuring on the physical and spatial characteristics of soil properties are rarely considered. The objective of this study was to quantify the impacts of restoration efforts on the spatial characteristics of soil properties by means of a pre‐ and post‐restoration comparison. We determined that the spatial patterns of soil organic matter (SOM) and exchangeable phosphorus (P_ex) appeared less variable in the years following restoration than in the years before restoration. Mean SOM significantly decreased after restoration, whereas mean P_ex significantly increased. The spatial characteristics and mean concentrations of NO₂–NO₃ did not differ much between sampling dates. The loss of this spatial patterning in SOM and P_ex and the decrease in SOM pools may represent negative impacts of restoration on important ecosystem characteristics. This study demonstrates that soil properties and spatial patterns can be negatively affected by restoration activities potentially hindering ecosystem development and function.     

Allelic frequencies and statistical data obtained from 12 codis STR loci in an admixed population of the Brazilian Amazon

The allelic frequencies of 12 short tandem repeat loci were obtained from a sample of 307 unrelated individuals living in Macapá, a city in the northern Amazon region, Brazil. These loci are the most commonly used in forensics and paternity testing. Based on the allele frequency obtained for the population of Macapá, we estimated an interethnic admixture for the three parental groups (European, Native American and African) of, respectively, 46%, 35% and 19%. Comparing these allele frequencies with those of other Brazilian populations and of the Iberian Peninsula population, no significant distances were observed. The interpopulation genetic distances (F(ST) coefficients) to the present database ranged from F(ST) = 0.0016 between Macapá and Belém to F(ST) = 0.0036 between Macapá and the Iberian Peninsula.     

Termite (Insecta: Isoptera) Species Composition in a Primary Rain Forest and Agroforests in Central Amazonia

Termites play important roles in organic matter decomposition, nutrient cycling, and soil structure in tropical rain forests. When forests are replaced by agriculture, termite species richness, abundance, and function often decline. We compared the termite assemblage of a primary forest site with that of a low plant diversity, palm-based agroforest (five plant species) and a high plant diversity, home-garden agroforest (10 plant species) using a rapid biodiversity assessment protocol. In comparing the primary forest termite species composition to previously published studies, we found soil feeders and the Apicotermitinae to be more dominant than previously reported in Amazonia. Thirty percent of the species belonged to the Apicotermitinae, and an unusually high percentage (57%) of species were soil feeders. Unexpectedly, the palm-based agroforest, despite its lower plant diversity, was closer to primary forest in termite species composition, rate of species accumulation, and proportions of species in taxonomic and functional classes than was the home-garden agroforest. This suggests that particular plant attributes may better determine the termite assemblage than plant diversity alone in these agroecosystems. Unlike other agroecosystems reported in the literature, Apicotermitinae and soil feeders were proportionally more abundant in these agroforests than in primary forest. The ability of agroforests to support populations of soil feeders has a potentially positive effect on soil fertility in these agroecosystems; insomuch as feeding guild is a proxy for function, these closed-canopy agroforests may be able to sustain the same termite-mediated functions as primary forest.     

Palms,Pastures, and Swidden Fields: The Grounded Political Ecology of “Agro-Extractive/Shifting-cultivator Peasants” in Maranhão,Brazil

This article examines transformations associated with changes in resource use and land cover dynamics in the community of São Manoel, Maranhão state, in the eastern Brazilian Amazon. The shifting cultivator peasants in São Manoel integrate swidden fields for annual cropping, the extraction of babassu palm products, and pastures for cattle ranching. Since the early twentieth century, predominant vegetative cover patterns have been altered from species-rich mature forests to secondary succession with babassu dominant to pasture or swidden fields containing palm stands of various densities. A grounded political ecology of resource use in the area suggests that management strategies and the resulting land cover dynamics integrate site-specific decisions of peasant producers. I discuss the trajectory of production strategies in São Manoel since the establishment of the community in the 1920s, and identify the multiple dimensions affecting resource use and environmental outcomes, with an emphasis on the period following land struggles and the recovery of peasant tenure rights in the mid-1980s. The analysis indicates that socionatural trajectories that optimize resource use and address the socioeconomic needs of the community include the maintenance of palm/pastures associations.     

Cofán Indians’ Monitoring of Freshwater Turtles in Zábalo,Ecuador

The Cofán Indians of Aguarico and Zábalo Rivers in Ecuador in 1990 began a turtle recuperation effort by raising turtle hatchlings (Podocnemis expansa and P. unifilis) in small pools. To evaluate the effectiveness of this program, the Cofán developed and tested three methods to document changes in the populations of turtles. The first method consisted of interviews with people from neighbouring communities about their perceptions of changes in turtle abundance. The second method was a direct count of turtles observed along the rivers from canoe. The third method was an indirect count, involving turtle nest censusing along community beaches. Two of the methods yielded numerical, statistically positive turtle population trends. The turtle program has influenced the community's perception of turtle conservation issues so that, instead of hunting the adults and eggs, they now protect them. The training in record-keeping permits them to make a transparent history of the equitability of access to the turtle egg resource. The Cofán monitoring experience strengthened their successful petition to the Ecuadorian government for the rights to manage their territorial lands within the Cuyabeno Wildlife Reserve, and to receive protected area status and management rights to other ancestral lands. The experience gained by the Zábalo monitors is now serving as a model for the design and implementation of the park monitoring system of the newly-established Cofán Park Ranger Corps, which will be patrolling three Ecuadorian Ecological Reserves which overlap Cofán inhabited areas.     

Mitochondrial sequence variation in the Guahibo Amerindian population from Venezuela

New data were obtained on mitochondrial DNA (mtDNA) from Guahibo from Venezuela, a group so far not studied using molecular data. A population sample (n = 59) was analyzed for mtDNA variation in two control-region hypervariable segments (HV1 and HV2) by sequencing. The presence or absence of a 9-bp polymorphism in the COII/tRNA(Lys) region was studied by direct amplification and electrophoretic identification. Thirty-eight variable sites were detected in regions HV1 and HV2, defining 26 mtDNA lineages; 23.7% of these were present in a single individual. The 9-bp deletion was found in 3.39% of individuals. Nucleotide and haplotype diversities were relatively high compared with other New World populations. The identified sequence haplotypes were classified into four major haplogroups (A-D) according to previous studies, with high frequencies for A (47.46%) and C (49.15%), low frequency for B (3.39%), and an absence of D.     

Colour forms of Amazonian cichlid fish represent reproductively isolated species

Laboratory mate choice experiments have confirmed species status for cichlid fish in the African Great Lakes that differ in colour and little else. Colour differences between allopatric populations of the South American cichlid genus Apistogramma are known for many species, yet the status of such populations has not been previously tested. Analysis of the genetic relationships and mate choice characteristics of populations previously described as Apistogramma caetei from eastern Amazonia indicates genetic differentiation into at least three allopatric lineages, which also show strong prezygotic isolation through female mate choice, confirming them as Biological species. If future studies confirm that this result is indicative of a general trend, the species richness of the South American cichlid fishes may presently be seriously underestimated.     

Leaving the Oil Under the Amazon: Ecuador's Yasuní-ITT Initiative

Oil and gas concessions now cover vast swaths of the western Amazon, including protected areas and indigenous territories. The Yasuní-ITT Initiative, Ecuador's innovative proposal to leave nearly a billion barrels of oil locked beneath Yasuní National Park, is the first major effort to reverse this trend. We provide a concise overview of the initiative, including an in-depth look at its widely lauded goals of protecting biodiversity, respecting indigenous peoples' territory, and combating climate change. We also discuss the proposal's lingering caveats, such as technical questions regarding the generation of financial resources to replace the forgone oil revenue. We conclude that the Yasuní-ITT Initiative is a potentially precedent-setting advance towards avoiding damaging oil and gas development in sensitive areas.     

Mammalian Densities in a Neotropical Wetland Subject to Extreme Climatic Events

Effective management and conservation of an ecosystem requires information on species assemblages as well as reliable estimates of population sizes to plan, implement and evaluate management strategies. The Brazilian Pantanal is one of the world's largest freshwater wetlands and considered a priority landscape for wildlife conservation. It is subject to pluri-annual extreme dry and wet periods, which cause extreme flood and drought events, which strongly affect wildlife. Using the line-transect method, this study examined the distribution of densities and metabolic biomass of medium- to large-sized nonvolant mammals in forest, cerrado and floodplain landscapes, in an area with low anthropogenic influence, in the central area of the Brazilian Pantanal during a prolonged drought. Comparisons with a previous survey conducted during years of average rainfall in part of the study area suggest that population fluctuations of certain species are closely associated with water due to the drought. Results from this study showed that mammal assemblages varied between landscapes. Forested landscapes have the highest densities of mammals and are the most important in terms of relative energy consumption. In addition, at the time of the study, frugivores were found to have higher energy consumption than browser/grazers across the three landscapes; most fruits are produced in forested areas stressing their importance. By converting forested landscapes into grasslands, the intensification of ranching practices seriously threatens biodiversity and ecological processes in the region.     

Seasonal changes in chlorophyll distributions in Amazon floodplain lakes derived from MODIS images

To assess seasonal changes in phytoplanktonic chlorophyll distributions in Amazon floodplain lakes, a linear mixing model was applied to Moderate Resolution Imaging Spectroradiometer (MODIS) reflectance data acquired at four river stages: rising (April), high (June), decreasing (September), and low (November). The study area is located in a floodplain reach from Parintins (Amazonas) to near Almeirim (Pará). A three-end-member mixing model designed to uncouple three fractions [high suspended inorganic matter (ip), low inorganic suspended matter (w), and high chlorophyll a (Chl)] was tested in Lake Curuaí (1.5°S 55.43°W) based on field sampling done almost concurrently with satellite overpasses. During high water, phytoplankton patches are confined to lakes closer to terra firme under the influence of clear water inflow, whereas during the low and decreasing water stages, the patches are more evenly distributed over the floodplain.