Figs 2‒5. Biogeographic boundaries and the Central Asian deserts. 2 in Can biogeography help bumblebee conservation?

Figs 2‒5. Biogeographic boundaries and the Central Asian deserts. 2. Principal faunal (biogeographic) regions world-wide derived directly from bumblebee data, include an Oriental Region (1, black), a Southeast Asian Region (2, light grey), a Palaearctic Region (3, dark grey), a North American Region, (4, mid grey), a Mesoamerican Region (5, light grey), an Andean Region (6, dark grey), and a Lowland South American Region (7, light grey). Principal faunal regions are identified from grid-cell bumblebee faunas (Fig. 1) using the TWINSPAN procedure that combines ordination with classification (Williams 1996, data updated). Background map as in Fig. 1. 3. One of the most marked transition zones between bumblebee faunas globally (in orange) corresponds to the arid zone of the Central Asian deserts (the centre of this arid belt is traced by the dotted black line). The map scores measure the differences in species composition among bumblebee faunas within neighbourhoods of grid cells (Fig. 1) using the β-3 spatial turnover index (Williams 1996; Williams et al. 2022b). Background map and colour scale as in Fig. 1. 4. Image of Asia based on satellite images shows wet (green) and arid (yellow) regions, with the Central Asian desert belt, its centre traced out with a dotted red line (cf. Fig. 3). Image (without line) from GoogleEarth. 5. Searching for bumblebees across the Central Asian arid belt of Inner Mongolia with Huang Jiaxing – in the northern wooded/grassland edge zones finding some old favourites from Europe, including Bombus distinguendus Morawitz, 1869, B. subterraneus (Linnaeus, 1758), B. consobrinus Dahlbom, 1832, B. muscorum (Linnaeus, 1758), B. humilis Illiger, 1806, B. pascuorum (Scopoli, 1763), B. lucorum (Linnaeus, 1761) and B. cryptarum (Fabricius, 1775), as well as some striking local species in the desert-edge zones (north and south), such as B. sibiricus (Fabricius, 1781) and the large B. amurensis Radoszkowski, 1862, but finding no bumblebees here nearer the middle (An et al. 2014; Williams et al. 2017a).