AbstractDifferential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.
The concept of "High Conservation Value" which was initially used by the Forest Stewardship Council, now plays an increasingly important role in several areas, and most significantly in the design and implementation of development projects. Within the framework of certification of community forests in Cameroon, this concept has been implemented in close collaboration with interested communities. Based on the activities conducted, it is worth noting that the consideration of informal management methods appear to result in better protection of biodiversity. Several categories of High Conservation Values were identified in 2 community-managed forests (Coopérative des Paysans de la Lékié & Bimbia Bonadikombo Community Forests) in Cameroon. Rare or endangered ecosystems, more than 300 plant species and more than 20 wildlife species, including endemic, rare, threatened or endangered species were found. Traditional conservation methods based on culture, as well as some ancestral practices and beliefs help to achieve this protection. Decision-makers and academics should learn from this empirical knowledge for protection programmes and projects of biodiversity.
AbstractWetlands have recently become of high environmental interest. The restoration effects on habitats like fens are one of the main topics of recent restoration ecology, especially due to their interconnection with other ecosystems. We studied the manual mowing effect on abandoned fen using the response of three study taxa: diurnal butterflies, flower-visiting beetles and vascular plants. Our results showed that butterflies seems to be quickly-responding indicator taxon for evaluation and that restored management had a positive effect on both species richness and composition of this insect group. The results indicated that the manual mowing effect could be rapid. In comparison with the surrounding landscape, we found that: (i) the manually mowed site was most similar to strictly protected area, (ii) some species of high conservation value could reach higher abundance in restored than protected site, and (iii) manual mowing could bring a new type of habitat (i.e., spatial heterogeneity) compared to the other management types (abandonment, conservation and agri-environmental mowing). The main implication seems to be optimistic for practice: The manual mowing of long-term abandoned fen is leading to the creation of habitat with high conservation value in a relatively short time.
Variant responses of tree seedling to seasonal drought stress along an elevational transect in tropical montane forests