Deforestation and managerial scales in Côte d’Ivoire

ABSTRACT

We provide evidence that a factor contributing to the specific patterns of deforestation in Côte d’Ivoire is the set of spatial units of management used to structure wood extraction. Timber harvests were organized through a system of harvest perimeters, called “chantier,” for nearly a century. Chantiers were initiated as managerial instruments. However, their use as spatial tool for profit maximization led to positional anarchy. The lack of support for sustainable harvests from the legislation, the restoration system, and the tree-based policy governing the use of their content made the chantier the basis of a one-way resources extraction. Managerial scales facilitated clearing of forests. None served to regenerate forests. Using historical and official documents, satellite and cartographic data, we attempted to demonstrate how managerial scales aiming to organize logging have contributed to deforestation. We discuss the phases of fragmentation in the rainforest, the managerial scales, and the environmental context in which they were applied. We summarize the legislation that governed the managerial scales and how these scales organized space but the tree species-based policies and activities resulted in the forest’s dilapidation. The final section addresses the use of these scales in the creation of data for policy making.     

A comparison between visual estimates and image analysis measurements to determine septoria leaf blotch severity in winter wheat

Methods to estimate disease severity vary in accuracy, reliability, ease of use and cost. Severity of septoria leaf blotch (SLB, caused by Zymoseptoria tritici) was estimated by four raters and by image analysis (assumed actual values) on individual leaves of winter wheat in order to explore accuracy and reliability of estimates, and to ascertain whether there were any general characteristics of error. Specifically, the study determined: (i) the accuracy and reliability of visual assessments of SLB over the full range of severity from 0 to 100%; (ii) whether certain 10% ranges in actual disease severity between 0 and 100% were more prone to estimation error compared with others; and (iii) whether leaf position affected accuracy within those ranges. Lin's concordance correlation analysis of all severities (0–100%) demonstrated that all raters had estimates close to the actual values (agreement: ρ_c = 0·92–0·99). However, agreement between actual SLB severities and estimates by raters was less good when compared over short 10% subdivisions within the 0–100% range (ρ_c = ?0·12 to 0·99). Despite common rater imprecision at estimating low and high SLB severities, individual raters differed considerably in their accuracy over the short 10% subdivisions. There was no effect of leaf position on accuracy or precision of severity estimate on separate leaves (L1–L3). Pursuing efforts in understanding error in disease estimation should aid in improving the accuracy of assessments, making visual estimates of disease severity more useful for research and applied purposes.     

Enrichment of logging gaps with moabi (Baillonella toxisperma Pierre) in a Central African rain forest

Studies of regeneration in African rain forests suggest that without silvicultural treatments, natural succession in logging gaps may not result in the establishment of timber species. In this paper we present the results of an experimental enrichment planting with moabi (Baillonella toxisperma Pierre), a valuable and important timber species harvested in Central Africa. Although forest gaps are generally considered as favourable for the regeneration of this species, a survey conducted in a forest concession in south-eastern Cameroon provided an estimate of only 12.7 seedlings ha⁻¹, suggesting that the species was, in fact, poorly represented in logging gaps within the study area. To further investigate the dynamics of the moabi in logging gaps, 795 seeds were sown in 15 logging gaps and 410 nursery-raised seedlings were planted in 15 other gaps. A biannual monitoring program over a 30-month period showed a lower survival rate for seedlings from sowing (75.9%) compared to that of nursery-raised seedlings (95.3%). Planted seedlings reached an average of 229.3 cm tall whereas seedlings from sowing were 167.5 cm tall, with the observed difference roughly corresponding to the average height of the nursery-raised seedlings at the time they were introduced to the logging gaps. After 30 months, the diameters of planted seedlings (16.8 mm) were also greater than those of the directly sown individuals (12.5 mm). Forest gap characteristics significantly influenced the growth of the plants. Factors accounting for the differences were total solar radiation, the soil content of coarse sand, the topographic position of the gap, the vegetation cover and the density of Macaranga spp. Whilst total solar radiation had a positive influence on growth, the remaining factors had impacted growth negatively. A streamlined technique was tested by planting 7 seedlings in 250 gaps. Without additional site maintenance, 29.3% of the moabi seedlings emerged naturally from the competing vegetation after 24 months. With biannual maintenance some 89.4% of seedlings became successfully established. Clearance operations had no significant influence on the height of plants whilst plant diameter was greater in cleared gaps. The total cost of the enrichment technique was 5.5 EUR per gap without maintenance and 7.5 EUR per gap with a single maintenance measure. Whilst long-term monitoring is needed, this study suggests a high survival rate of moabi introduced in logging gaps, and a growth rate 10 times higher than previously reported under canopy cover. These findings, combined with the low costs of the enrichment technique, support the use of silvicultural measures in logging gaps to restore the forest.     

Sediment trace metal contamination in the Ivory Coast,West Africa

To help expand our global perspective on trace metal contamination, concentrations of Cu, Fe, Hg, Mn, Ni, Pb, and Zn were determined for sediments from the Ebrie Lagoon in the Ivory Coast, a developing West African nation. Excess loading of several metals, especially Hg, Pb, and Zn was found at several sites. The maximum concentration of Hg measured in sediments from the Ebrie Lagoon (2250 ng g^?1) is about 30 times greater than natural levels. Similarly, Pb and Zn concentrations for the Ivorian lagoonal sediments are as high as 250 and 560 μg g^?1, respectively, showing sizeable anthropogenic inputs. Trace metal sources to the Ebrie Lagoon include untreated sewage and industrial wastes.     

Molecular bacterial characterization and free amino acids composition in Ivorian traditional fermented fish produced by two methods

The aim of this study was to show and compare the as yet unknown microbiological and biochemical composition of ??adjuevan??, an Ivorian traditional salted fermented fish that is produced by two main processing methods and consumed for its flavor. Method 1 uses the full fish and method 2 uses fish fillets. The pH was around 6 and the major organic acids were acetic and butyric acids in all adjuevan samples. The free amino acid profile varied according to the fermentation method, although the major free amino acids were valine, leucine, alanine, aspartic acid and glutamic acid, ranging in concentration from 101.7 to 745.4?mg/100?g, for both methods. Adjuevan produced using method 1 had the best composition of free amino acids. Lactic acid bacteria counts were between 6.0?×?10⁴ and 2.6?×?10⁵?cfu/g for method 1 and 5.9?×?10³ and 2.1?×?10⁴?cfu/g for method 2. Yeasts were detected in all samples. Microbial ecology analysis using PCR-denaturing gradient gel electrophoresis (DGGE) revealed the presence of more bacterial species than previously reported in fermented fish. Bacterial species varied according to fermentation method. Species such as Staphylococcus xylosus, S. lentus, S. saprophyticus, and Bacillus megaterium were found only in samples produced by method 1, while those of Staphylococcus piscifermentans, Bacillus mycoides, and Corynebacterium xerosis were found only in samples produced by method 2. Using specific primers, we detected several lactic acid bacteria (LAB), such as Lactobacillus, Pedicoccus, Lactcoccus, Streptococcus, and Leuconostoc species; the composition these bacteria in adjuevan samples varied according to the preparation method, but were not found to be dominant. We conclude that the molecular PCR-DGGE method can be used to differentiate fermentation methods by LAB profile analysis. A mixture of strains of S. xylosus, S. saprophyticus, S. cohnii, and S. piscifermentans were predominant, and LAB such as L. fermentum, L. lactis, L. pseudomesenteroides, L. raffinolactis, L. lactis subsp cremoris could be potentially beneficial for the specific flavor of each type of adjuevan to be selected as possible starter cultures for the development of a starter culture to improve adjuevan nutritional quality.     

WHO 2006 child growth standards: implications for the prevalence of stunting and underweight-for-age in a birth cohort of Gabonese children in comparison to the Centers for Disease Control and Prevention 2000 growth charts and the National Center for Health Statistics 1978 growth references

OBJECTIVES: To assess the proportion of children being stunted and underweight-for-age at 3, 9 and 15 months in Lambaréné, Gabon, using the WHO child growth standards released in 2006 as compared with the Centers for Disease Control and Prevention (CDC) 2000 and the National Center for Health Statistics (NCHS) 1978 child growth charts/references. DESIGN AND SETTING: Prospective birth cohort in Lambaréné, Gabon. SUBJECTS: Two hundred and eighty-nine children from birth to 15 months of age. METHODS: Weight and length were recorded at 3, 9 and 15 months. Corresponding Z scores for stunting and underweight-for-age were calculated for the three different standards/references. Children with a height-for-age or weight-for-age below -2 SD of the corresponding reference median (Z score < or = -2) were classified as stunted or underweight-for-age, respectively. RESULTS: With the new WHO 2006 standards a higher proportion (4.0%) of 3-month-old infants were underweight compared with the CDC (1.0%) or the NCHS (0.7%) child growth charts/references. In contrast to the NCHS references or the CDC charts, this proportion did not increase from 3 to 9 months or from 9 to 15 months. The proportion of children being stunted was highest (above 20%) with the WHO 2006 standards at all three ages. Again, in contrast to the old standards, this proportion did not increase from 3 to 9 months or from 9 to 15 months. CONCLUSIONS: The present results show considerably different growth faltering patterns for Gabonese children depending on the growth charts used to assess the prevalence of stunting and underweight. Shifting to the new WHO child growth standards may have important implications for child health programmes.     

Genetic Diversity and Core Collection for Potato (<Emphasis Type="BoldItalic">Solanum tuberosum</Emphasis> L.) Cultivars from Cameroon as Revealed by SSR Markers

Twelve pairs of SSR markers were used to evaluate the genetic diversity of 138 accessions of potato cultivars from the Western Highlands region of Cameroon. The average Polymorphism information content (PIC) value (0.74) and number of alleles (7.08) indicated a high genetic diversity of the potato cultivars tested. Analysis of molecular variance revealed that most of the genetic variations are found within geographic region (≥ 91%), resulting in high gene flow (Nm > 4 individuals). Local varieties had significantly more alleles than exotic varieties. Genetic diversity estimates for accessions from low elevations were significantly lower than those from medium and high elevations. Cluster analysis showed three clusters; the model-based approach inferred two gene pools. Genotypes revealed a high level of admixture between gene pools within locations and elevations. A core collection identified in this study composed of 27 individuals representing 19.57% of the whole collection and captured 99.15% of the total alleles found.