Need for shared internal mound conditions by fungus-growing Macrotermes does not predict their species distributions, in current or future climates

Abstract

The large, iconic nests constructed by social species are engineered to create internal conditions buffered from external climatic extremes, to allow reproduction and/or food production. Nest-inhabiting eusocial Macrotermitinae (Blattodea: Isoptera) are outstanding palaeo-tropical ecosystem engineers that evolved fungus-growing to break down plant matter ca 62 Mya; the termites feed on the fungus and plant matter. Fungus-growing ensures a constant food supply, but the fungi need temperature-buffered, high humidity conditions, created in architecturally complex, often tall, nest-structures (mounds). Given the need for constant and similar internal nest conditions by fungi farmed by different Macrotermes species, we assessed whether current distributions of six African Macrotermes correlate with similar variables, and whether this would reflect in expected species' distribution shifts with climate change. The primary variables explaining species’ distributions were not the same for the different species. Distributionally, three of the six species are predicted to see declines in highly suitable climate. For two species, range increases should be small (less than 9%), and for a single species, M. vitrialatus , ‘ very suitable’ climate could increase by 64%. Mismatches in vegetation requirements and anthropogenic habitat transformation may preclude range expansion, however, presaging disruption to ecosystem patterns and processes that will cascade through systems at both landscape and continental scales. This article is part of the theme issue ‘The evolutionary ecology of nests: a cross-taxon approach’.

A review of the global climate change impacts, adaptation strategies, and mitigation options in the socio-economic and environmental sectors

“…The number of persons who have been forced to relocate within their own country as a result of natural disasters is depicted in Figure 3. Increasing temperatures are anticipated to have an influence on the interior parts of the continent (Seymour et al, 2023). Many plant species are threatened with extinction as a result of changes in weather patterns brought on by a scarcity of natural resources (water), an upsurge in glacier melting, and increasing mercury (Mihiretu et al, 2021).…”

“…Commercial tourism's many origins make it a potent instrument for economic growth and social progress at the local, regional, national, and international levels (Scott, 2021). Like many other fields, the tourism sector is threatened by global warming because the weather is one of the primary reasons why certain areas are popular tourist destinations.…”

The evolutionary ecology of nests: a cross-taxon approach

“…Eusocial Macrotermitinae evolved fungus-growing as a means of providing food for the termites, yet increasing ambient temperatures with ongoing climate change may mean that fungus-growing is unviable. Seymour et al [66] show that the distribution of six African Macrotermes species is correlated with similar environmental variables; however, while three of the six species will likely lose substantial suitable habitat in a changing climate, two species will lose only a small amount of habitat and one species is predicted to gain habitat [66].…”

“…Seymour et al . [ 66 ] show that the distribution of six African Macrotermes species is correlated with similar environmental variables; however, while three of the six species will likely lose substantial suitable habitat in a changing climate, two species will lose only a small amount of habitat and one species is predicted to gain habitat [ 66 ].…”