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Copyright of Naturaliste Canadien is the property of La Societe Provancher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Like the Sahelian countries, in Burkina Faso, the effects of climate change associated with anthropogenic actions threaten disappearance certain endemic plant species by accelerating the degradation of their ecosystems. The present research aims to analyze the impacts of climate change and anthropogenic actions on the stands of Carapa procera and its natural habitat in the rural district of Bérégadougou (Cascades region of Burkina Faso). Thus, a systemic approach (global and integrated analysis of the biophysical and societal components) was adopted. Survey data, forest inventory, climatic parameters, the national topographic data base and the land cover database were collected and analysed. The results indicate a negative evolution of bioclimatic factors between 1985 and 2014. In 29 years, the area of gallery forests (Carapa procera ecosystem) decreased by 34,23% in favour of Savannah (29,85%) and farms (4,38%). The study also revealed that climate change combined with biotic factors (anthropogenic and zoological actions) induced the modification and regression of Carapa procera stands and their natural habitat. [ABSTRACT FROM AUTHOR]

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Our forest information needs are growing with high requirements in terms of accuracy, spatial resolution and costs. Thus, forest inventories innovation is a constantly evolving field. In this study, we evaluated the contribution of digital height models (DHM) as auxiliary data to improve the accuracy of inventory estimates. Two study areas were selected. The first covers the Nièvre 'department', where a recent campaign of aerial images (winter 2011) was used to generate a DHM. The second covers the Vosges area of the Haut-Rhin 'department', and was described by a LiDAR acquisition (1360 km², in spring 2011) which allowed the production of a state of the art DHM. Other forest information layers such as the main ecological regions, the « sylvoécorégions » as well as maps of forest types produced by IGN were also used as auxiliary variables. The results showed that for two key forest parameters examined (i.e. forest area and volume), the relative efficiency was improved by a factor 1 to 8 using DHM and forest type maps. This efficiency can be interpreted as the factor by which the initial inventory sample should be multiplied to obtain the same precision than when using the relevant auxiliary variables. This efficiency, however, varies depending on the study area. For an area mainly composed of deciduous forests like the Nièvre 'département', winter images did not lead to a quality DHM, making it impossible to quantify the real contribution of photogrammetric DHM. However, in areas of pure conifer stands, the calculated efficiency in volume estimates ranged from 1.2 to 1.7, which is similar to the results obtained in the Vosges, where the LiDAR DHM allowed a gain of 1.8 in efficiency for volume estimates. In general, the auxiliary variables improve the accuracy of inventory estimates, provided they are correlated to the parameters of interest. DHM are thus certainly a possible source of accuracy improvement for forest inventories that must be carefully considered. [ABSTRACT FROM AUTHOR]

While the use of field plots and airborne LiDAR data for the estimation of forest parameters has been intensively investigated in the past ten years, the issue of the evaluation of their accuracy at the compartment level (surface of a few hectares) remains poorly documented. Based on a full-calliper inventory of 35 compartments representing 380 ha, the present study compares different strategies for the mapping of LiDAR predictions and their aggregation by compartment. Results show that the prediction error decreases between estimations at the plot and those at the compartment levels: from 15 to 6.4% for basal area, 26 to 7.7% for stem density and 6.5 to 3.4% for mean diameter. At the compartment level, a LiDAR-based inventory thus displays an accuracy similar to a full-calliper inventory, for basal area. For the mapping step, it is crucial to respect the size of field plots used for calibration, whereas for the aggregation step the handling of compartment borders remains tricky for all forest parameters. [ABSTRACT FROM AUTHOR]

Copyright of Fruits is the property of International Society for Horticultural Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)