Carex spp).
Finally, the most suitable habitats had higher land productivity
heterogeneity (Fig. 5E and 5H) which was expected as species richness
and abundance often increases with habitat diversity (Chasko and Gates
1982; Wen et al. 2015). Although human disturbance can sometimes
increase diversity in such wetland systems, here the habitat suitability
decreases with human disturbance (Fig. 5F), reflecting the negative
impacts of human presence (Lei et al. 2019b).
Conservation challenges
The results of this study highlight a major challenge from future
climate change on the A. erythropus . First, many climate change
models predict increasing spring temperatures and earlier snow melting
(IPCC 2014), which will lead to flooding, submergence, permafrost
erosion and loss and change in low-lying coastal wetlands (Prowseet al . 2006). As the predicted summering habitats were
concentrated in the lowland coastal zone of the Laptev and East Siberian
Seas, the projected sea level rise (IPCC 2014; Wrona et al . 2016)
and increasing river flows (Karlsson et al . 2012; Wrona et
al . 2016) could cause extensive habitat loss. The response curves of
habitat suitability to topographic variables suggest that the relatively
hilly and rugged landscape would restrict extension of suitable habitat
landward and such “habitat squeeze” (Leo et al . 2019) would be
highly detrimental to A. erythropus . Second, the models suggested
that there was an “optimal window” in terms of mean summer temperature
and precipitation, which could be interpreted as the realized climatic
niche of A. erythropus (Merow et al . 2016). Rising
temperatures under future climate change scenarios means that the
temperature niche could shift northerly, which is sea. Third, studies
have shown that encroachment of shrubs following projected climate
change (e.g. Salix ovalifolia and Dushecia fruticosa ) into
the wet meadows (Carlson et al . 2018), would likely decrease
quantity and quality of available food resources.
Finally, there is the threat from increasing anthropogenic disturbance;A. erythropus avoids locations near active mines (although can
colonize such areas after mining is finished) (Egorov and Okhlopkov
2007; Solovieva and Vartanyan 2011). Currently, human population levels
in the predicted summering range is among the lowest in the world, and
the coastal areas of this region are some of the least explored.
However, the coast of the Russian Arctic is likely to undergo rapid
development as there are reserves of oil, gas, metals and other natural
resources which could be exported, with additional infrastructure,
through the North-East Passage to European and Asian ports (Martiniet al . 2019), more information on these potential developments
can be found athttp://ecoline-eac.com/proekty/peschanka/deposit.html ), and these
developments present perhaps the most difficult challenges to the future
of eastern sub-population of A. erythropus .