Andropogon pusillus

The main threat to this species is from grazing and trampling by domestic livestock, which are present at all of the collection localities except for Mount Cameroon (Onana and Cheek 2011). As this species is an annual plant, any disruption to the culms during the reproductive phase may inhibit the production of seeds for the next generation (Onana and Cheek 2011). Mount Bamboutos has no official protection and the entire mountain now shows evidence of human occupation, with much of the natural vegetation now replaced by crop fields, eucalyptus plantations and pasture (Tchassem et al. 2019, Ngoufo 1992). This uncontrolled land clearance, the rapid and intensive occupation of the area by humans, and the lack of management have caused degradation of the mountain (Ngoufo 1992). Degraded sites are abundant at high altitudes, and above 1,800 m asl, where this species occurs, Fulani livestock grazing is prominent, with herders set fire to grasslands between January and March to promote the regrowth of grasses (Ngoufo 1992, Tchassem et al. 2019). Having previously only used the mountain for livestock grazing, humans occupied the high slopes of Mount Bamboutos in the 1970s and this process was rapid and destructive (Tchassem et al. 2019, Ngoufo 1992). The dense populations on and around the mountain now depend on it for their livelihood, and as such, agricultural activities are increasing, often using a slash and burn approach (Tchassem et al. 2019, Green Vision 2017, Ngoufo 1992). Between 2014 and 2016, the creation of new farms was frequently observed, and they now occur up to an altitude of 2450 m asl (Tchassem et al. 2019). The Fulani people in the area only practice subsistence farming, however in the Mbouda community, there has been a recent shift to the growing of cash crops such as eucalyptus, maize, legumes and potatoes (Tchassem et al. 2019, Ngoufo 1992). This shift to cash crops has been facilitated by the humus-rich fertile soils of the high slopes of the mountain, and the difference in climate at higher altitudes (Ngoufo 1992). Alongside the increase in farming on Mount Bamboutos, there has been an increase in the use of agrochemicals, predominantly as pesticides against weeds (Tchassem et al. 2019). Additionally, a mining concession covers the mountain (Global Forest Watch 2020), and the land of Mount Bamboutos, with its steep slopes and a high altitude, is ecologically fragile (Ngoufo 1992). Overgrazing, uncontrolled forest clearing, and the construction of farming furrows, is causing erosion on the mountain slopes (Ngoufo 1992). This is leading to landscape instability, resulting in landslides (Ngoufo 1992, Green Vision 2017). Similarly, the plateau grasslands of both Tchabal Mbabo and Chappal Waddi (or Gangirwal) are heavily grazed by Fulani cattle and are subjected to annual burning (Fotso et al. 2001, Chapman 2004, Chapman et al. 2004).  Both of these grasslands now also suffer from overgrazing and erosion (Fotso et al. 2001, Chapman et al. 2004). This species also occurs on Mount Cameroon, an active volcano which erupts every 20 years (Fotso et al. 2001). However, it is unknown whether volcanic eruptions have any impact on this species and it has been found growing on old lava flow (Thomas K #9438). It is uncertain whether this species occurs within the Mount Cameroon National Park, which was designated in 2010 (Cronin et al. 2014). However, even if the species is extant within the national park, much of its boundary is not marked and a management plan has not yet been implemented (Cronin et al. 2014). Therefore, there area is still regularly exploited by local communities (Cronin et al. 2014). One of the collection localities on Mount Cameroon is near to Buea, and this species may face pressures from the town's human population (Google Earth 2020). Agriculture is important in the Mount Cameroon area, where it accounts for about 80% of household incomes in most towns in the area (The Ministry of Forestry and Wildlife 2014). This species is known to occur on the Eastern side of Mount Cameroon, where both forests and grasslands have been severely degraded by repeated anthropogenic bush fires (Fotso et al. 2001). Illegal logging also occurs on Mount Cameroon, mostly to supply the local towns (including Buea) with timber, and this may threaten this species which has been found on the edge of forests (Awono et al. 2014, The Ministry of Forestry and Wildlife 2014). These pressures are increasing as the human population grows (The Ministry of Forestry and Wildlife 2014). The fertile volcanic soils of Mount Cameroon attract farmers – both subsistence and agro-industrial – to the area, and this has resulted in further clearance habitat (Awono et al. 2014, Onana and Cheek 2011, Fotso et al. 2001). The higher elevation areas of Mount Cameroon remain relatively intact and there is little human activity above 2000 m asl (Cronin et al. 2014). As this species is thought to occur between 1800 and 2500 m, it may have somewhat escaped human impacts at its higher elevation localities. However, if the species does occur below 2,000 m asl on Mount Cameroon, it is likely to have been affected by anthropogenic activities. Further encroachment may pose a future threat, however this may be limited due to the relatively inaccessible terrain and low potential exploitation value of higher elevations (Cronin et al. 2014).