Documenting Biogeographical Patterns of African Timber Species Using Herbarium Records: A Conservation Perspective Based on Native Trees from Angola

Abstract

In many tropical regions the development of informed conservation strategies is hindered by a dearth of biodiversity information. Biological collections can help to overcome this problem, by providing baseline information to guide research and conservation efforts. This study focuses on the timber trees of Angola, combining herbarium (2670 records) and bibliographic data to identify the main timber species, document biogeographic patterns and identify conservation priorities. The study recognized 18 key species, most of which are threatened or near-threatened globally, or lack formal conservation assessments. Biogeographical analysis reveals three groups of species associated with the enclave of Cabinda and northwest Angola, which occur primarily in Guineo-Congolian rainforests, and evergreen forests and woodlands. The fourth group is widespread across the country, and is mostly associated with dry forests. There is little correspondence between the spatial pattern of species groups and the ecoregions adopted by WWF, suggesting that these may not provide an adequate basis for conservation planning for Angolan timber trees. Eight of the species evaluated should be given high conservation priority since they are of global conservation concern, they have very restricted distributions in Angola, their historical collection localities are largely outside protected areas and they may be under increasing logging pressure. High conservation priority was also attributed to another three species that have a large proportion of their global range concentrated in Angola and that occur in dry forests where deforestation rates are high. Our results suggest that timber tree species in Angola may be under increasing risk, thus calling for efforts to promote their conservation and sustainable exploitation. The study also highlights the importance of studying historic herbarium collections in poorly explored regions of the tropics, though new field surveys remain a priority to update historical information.

The unrealized potential of herbaria for global change biology

“…Nonetheless, herbarium data can help identify species in decline and regions that may provide refuges (Farnsworth and Ogurcak , Romeiras et al. ), as well as capture the interactions between climate change and habitat conversion, notably to demonstrate how human land use limits the extent to which species can track their climatic niches (Feeley and Silman ).…”

“…For example, Romeiras et al. () used occurrence records from herbarium specimens to determine timber species that were of high conservation priority in Angola based on their range sizes and the extent of their ranges that overlapped with protected areas in the region. We suggest there may be many opportunities along these lines for conservation of plants of economic and/or cultural importance, including both timber species and wild crop relatives, which are often well‐represented in herbaria, with many specimens collected prior to intensification of global change.…”

Dynamic Patterns of Trees Species in Miombo Forest and Management Perspectives for Sustainable Production—Case Study in Huambo Province, Angola

“…The global ecoregions map of the World Wildlife Fund recognizes 15 biogeographic units in Angola. In the Central Plateau, miombo forests are the most widespread biogeographic unit [70,71]; our study focused on Huambo province within the Central Plateau ( Figure 1). The dominant soils are ferralsols at higher elevations and alluvial fluvisols at lower elevations.…”

“…Species selection was based on the abundance of the applicable species in the forests sampled, dominance of old trees of the same species, and past assessments of those species in the region [49,71]. Cores were extracted at a height of 1.3 m on the trees, and we extracted 50 cores of the selected tree species.…”

Edible insects of Northern Angola

“…The reasons for this are, on the one hand, logging that concentrates on Milicia excelsa or species of Entandrophragma, which have been historically exploited and therefore are under increasing pressure (Romeiras et al 2014) and, on the other hand, uncontrolled fires caused by the increasing agricultural activities of local people (Göhre et al 2016).…”