Dragonfly (Odonata) community structure in the Eastern Highlands Biodiversity Hotspot of Zimbabwe: potential threats of land use changes on freshwater invertebrates

Abstract

We examined the diversity and potential drivers of dragonfly distribution in a biodiversity hotspot of Southern Africa (Eastern Highlands, Zimbabwe) by surveying 30 sites (13 lentic and 17 lotic habitats) located within this region. Additionally, we identified the anthropogenic factors that may threaten Odonata diversity and abundance. Our results revealed that 27 odonate species are associated with dams and ponds, one species is associated with streams and four species are associated with swamp forests. Considering odonate diversity between protected and unprotected areas, we found significantly higher diversity of odonates in streams in protected areas compared to non-protected areas. Broadly, we found anthropogenic activities (e.g. commercial exotic tree plantations, mining activities, vegetation clearing) possibly affect Odonata diversity (by decreasing abundance and diversity) compared to those within protected and undisturbed habitats. Our results reveal that several human activities like human encroachment into riverine habitats potentially threaten the existence of freshwater species in this biodiversity hotspot and biodiversity hotspots elsewhere.

Environmental variables affect the diversity of adult damselflies (Odonata: Zygoptera) in western Amazonia

“…Thermal conformers may be affected profoundly by modifications in the riparian forest, and are thus considered to be habitat specialists, which supports their role as bioindicators of environmental impact (Oliveira Júnior et al, 2015;Calvão et al, 2016). In most cases, zygopteran species richness and abundance are reduced, and in extreme cases, local extinctions may occur (Oliveira Júnior et al, 2015;Brasil et al, 2018;Mafuwe & Moyo, 2020). Even when the riparian forest is not affected directly by the anthropogenic impact, the conditions of the surrounding matrix may also be important for the dispersal of the insects beyond the riparian zone (Calvão et al, 2016), which creates a habitat gradient that the species need to traverse (Dolný et al, 2014).…”

Use of maximum entropy (Maxent) niche modelling to predict the occurrence of threatened freshwater species in a biodiversity hotspot of Zimbabwe

“…C. elegans is known as a highly localised species known only from montane streams which are over 1200 m above sea level in Zimbabwe, Mozambique, South Africa and Malawi (Dijkstra & Clausnitzer, 2014;Samways, 2008). to have altitudes that peak to around 2100 m above sea level, with comparatively low temperatures and high rainfall (Mafuwe & Moyo, 2020;Timberlake, 1994). These environmental factors are known to be highly preferred by these montane freshwater species, A. inyange, C. elegans and S. rhodesianus (Darwall et al, 2009;Dijkstra & Clausnitzer, 2014;Mafuwe & Moyo, 2020;Samways, 2008).…”

“…(Dijkstra & Clausnitzer, 2014;Kipping et al, 2009;Mafuwe, 2019). Mafuwe and Moyo (2020) and 2016). Because the Chimanimani-Nyanga corridor has seen an increase in human activities such as agriculture, illegal mining and introduction of invasive species, leading to land degradation, water pollution and other negative environmental consequences (Chibvuma, 2015;Mafuwe & Moyo, 2020), we sought to model the potential geographical distribution of three threatened freshwater species (A. inyangae, C. elegans and S. rhodesianus) in the Eastern Highlands of Zimbabwe, using the maximum entropy (MaxEnt) niche modelling approach (sensu Phillips et al, 2006).…”

“…Our study focussed on a Southern African biodiversity hotspot in the Eastern Highlands of Zimbabwe, which harbours several freshwater species of conservation interests (e.g. birds, invertebrates, amphibians), including some rare and threatened species whose numbers and distribution are little known (Dalu et al, 2016; Darwall et al, 2009; Mafuwe & Moyo, 2020). Among these are the Inyngani river frog ( Amietia inyangae ), Elegant malachite ( Chlorolestes elegans ) and the Chimanimani stream frog ( Strongylopus rhodesianus ) that are on the IUCN Red List of Threatened Species.…”

“…Historical records between 1905 and 2013 show that the three species occur around Inyanga, Stapleford and Chimanimani highland areas for example in, Juliasdale, Mount Nyangani, Chimanimani National Park, John Meikle Research Station, Selborne Estate, Banti Forest Reserve, Ngorima Reserve East, along Haroni River and in Vumba National Park (Dijkstra & Clausnitzer, 2014; Kipping et al, 2009; Mafuwe, 2019). Mafuwe and Moyo (2020) also recorded C. elegans along Bridal Veil Falls in Chimanimani and along Nyangombe pool and river in Inyanga, over a two‐year sampling period (2015 and 2016). Because the Chimanimani‐Nyanga corridor has seen an increase in human activities such as agriculture, illegal mining and introduction of invasive species, leading to land degradation, water pollution and other negative environmental consequences (Chibvuma, 2015; Mafuwe & Moyo, 2020), we sought to model the potential geographical distribution of three threatened freshwater species ( A. inyangae , C. elegans and S. rhodesianus ) in the Eastern Highlands of Zimbabwe, using the maximum entropy (MaxEnt) niche modelling approach ( sensu Phillips et al, 2006).…”