Forest degradation and forest loss threaten the survival of many species and reduce the ability of forests to provide vital services. Clearing for agriculture in Angola is an important driver of forest degradation and deforestation. Charcoal production for urban consumption as a driver of forest degradation has had alarming impacts on natural forests, as well as on the social and economic livelihood of the rural population. The charcoal impact on forest cover change is in the same order of magnitude as deforestation caused by agricultural expansion. However, there is a need to monitor the linkage between charcoal production and forest degradation. The aim of this paper is to investigate the sequence of the charcoal value chain as a systematic key to identify policies to reduce forest degradation in the province of Bié. It is a detailed study of the charcoal value chain that does not stop on the production and the consumption side. The primary data of this study came from 330 respondents obtained through different methods (semi-structured questionnaire survey and market observation conducted in June to September 2013–2014). A logistic regression (logit) model in IBM SPSS Statistics 24 (IBM Corp, Armonk, NY, USA) was used to analyze the factors influencing the decision of the households to use charcoal for domestic purposes. The finding indicates that 21 to 27 thousand hectares were degraded due to charcoal production. By describing the chain of charcoal, it was possible to access the driving factors for charcoal production and to obtain the first-time overview flow of charcoal from producers to consumers in Bié province. The demand for charcoal in this province is more likely to remain strong if government policies do not aim to employ alternative sources of domestic energy.
Hyperaccumulators are rare ability of plants to accumulate excessive concentration of elements on roots and shoot tissues without any evidence of physiological stress. However, less research has been conducted in different environmental habitats. Hence, this study was conducted in Mount Magdiwata and Peatland Forest of La Paz, Philippines. The objectives of this research were to identify hyperaccumulator plants as well as analyze soil and plant elemental accumulations. Sampling stations were designated in stratified habitats. Collected soil and plant specimens were analyzed in the laboratory and data were interpreted using SPSS software. Cratoxylum sumatranum (Jack ) Blume, Syngramma alismifolia ( C. Presl ) J.Sm., Mitragyna speciosa Korth, Pneumatopteris laevis ( Mett ) Holtta and Pneumatopteris glabra ( Cope ) Holtt were species that shown hyperaccumulation criterion and had significant accumulation capacity in respective habitats. Manganese had accumulation capacity in the leaves of Mitragyna speciosa Korth above the thresholds level for heavy metal concentrations at 22393 mg/kg−1. Soil element Mg has higher accumulation in the leaves at 5257 mg/kg−1and Fe at 4298 mg/kg−1 both major soil elements had shown significant results. The accumulation capability of this identified species were prospective sources of hyperaccumulator plants onwards to phytoremediation technology to cleanse environmental toxicity.
En Guatemala, la producción del cultivo de papa se ve afectada por los nematodos Globodera rostochiensis y Globodera pallida. La capacidad de ambas especies para formar quistes complica su control y provoca el aumento de sus poblaciones. En Guatemala se reporta la presencia de ambas especies de nematodos por identificación morfológica, sin embargo, no se ha realizado una confirmación molecular. Este es el primer estudio para validar la presencia de ambas especies de nematodos por PCR múltiple y la determinación de la diversidad y estructura genética de las poblaciones utilizando marcadores moleculares. Se realizaron muestreos en cuatro departamentos productores de papa del país. La identificación por PCR se realizó con el cebador común ITS5 y los cebadores PITSr3 específico para G. rostochiensis y PITSp4 para G. pallida. La caracterización molecular se realizó con el marcador AFLP. Se confirmó la presencia de las dos especies de nematodos en los cuatro departamentos. Los índices de diversidad Shannon y heterocigosidad esperada revelaron mayor diversidad genética en G. rostochiensis (H = 0.311, He = 0.301) que en G. pallida (H = 0.035, He = 0.223). Los métodos NJ, DAPC y PCA exhibieron una débil estructura entre las poblaciones de ambas especies de nematodos. Los resultados sugieren un patrón de dispersión desde Quetzaltenango hacia el resto del país, atribuido a la comercialización de semilla contaminada con nematodos. Se sugiere promover programas de socialización sobre los beneficios del uso de semilla certificada, además de constantes monitoreos moleculares para un diagnóstico certero de ambas especies de nematodos.
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