Tree Species Diversity and Composition of Miombo Woodlands in South-Central Angola: A Chronosequence of Forest Recovery after Shifting Cultivation

Abstract

The study was carried out in the Cusseque area of the Municipality of Chitembo in south-central Angola. Our objectives were to assess the floristic diversity, the species composition, and stand structure of Miombo woodlands during regeneration after shifting cultivation. A total of 40 plots of 1000 m 2 were surveyed and analyzed, corresponding to mature forests/woodlands and three fallow types of different age. The analyses were based on plot inventories of all trees with DBH ≥ 5 cm. A total of 51 woody species, 38 genera, and 19 families were recorded. The dominant family was Fabaceae, with subfamily Caesalpinioideae being very abundant. Shannon Diversity and Evenness were highest in mature forests and young fallows, while the mature forest stands showed the highest species richness. A Principal Coordinates Analysis (PCoA) showed many species shared between the intermediate fallow types, but only few species were shared with young fallows. Mature forests formed a clearly distinct group. This study shows potential pathways of forest recovery in terms of faster regeneration after agricultural abandonment and, thus, the results presented here can be used in future conservation and management plans in order to reduce the pressure on mature forests.

Using Annual Landsat Time Series for the Detection of Dry Forest Degradation Processes in South-Central Angola

“…These forests mainly occur on soils with a medium nutrient content and are largely disturbed, forming woodlands of different densities and various species composition [33,36]. While woodland regeneration after slash-and-burn agriculture is fast in terms of species richness, species composition might not recover at all [37].…”

“…It is assumed that deforestation and forest degradation rates are unprecedentedly high, especially close to cities and infrastructures due to easy access and market opportunities [12]. While deforestation for agriculture has already been quantified [15], more subtle forest dynamics, like degradation processes in the study area, remain unstudied [37].…”

Vegetation survey of the woodlands of Huíla Province

“…The highest value of Shannon diversity found in this community supports the view that these woodlands may represent regrowth of typical miombo woodlands, as areas heavily impacted by agriculture are reported to hold tree species with high light demand and fast growth, like many Combretum species (Jew et al, 2016). These species recruit and establish easily following disturbance and in this way additional species are added to the otherwise typical miombo species Gonçalves et al, 2017). The presence of standing trees of the hardwood species Pericopsis angolensis was also documented in early succession of the south-central Angolan miombo woodlands (Gonçalves et al, 2017).…”

“…These species recruit and establish easily following disturbance and in this way additional species are added to the otherwise typical miombo species Gonçalves et al, 2017). The presence of standing trees of the hardwood species Pericopsis angolensis was also documented in early succession of the south-central Angolan miombo woodlands (Gonçalves et al, 2017). A threshold of H' = 2 has been mentioned as the minimum value above which an ecosystem can be regarded as medium to high diversity .…”

“…Recently, a few initiatives have started to document the fl oristic diversity of the region, though attention has been paid mostly to areas of particular botanical interest, such as the Angolan escarpment Gonçalves & Goyder, 2016;Gonçalves et al, in prep.). Studies addressing fl oristic diversity and woody species recovery following disturbance of the miombo woodlands in south-central Angola have also been conducted (Gonçalves et al, 2017;. However, much remains to be done in terms of vegetation assessment to characterise the main vegetation types and species associations of Huíla Province.…”