Winter temperature structures mangrove species distributions and assemblage composition in China

Abstract

Aim The identification of environmental variables associated with geographical range limits can shed light on the ecological and physiological constraints imposed by abiotic stresses. Mangrove forest is a coastal ecosystem restricted to the tropics and subtropics. However, the factors that influence fine‐scale assemblage composition of mangroves remain an open question. This study aimed to identify range‐limiting climate factor(s) associated with species composition that are likely to have influenced the evolution of mangroves. Location China. Time period 1950s–2013. Major taxa studied True mangrove species. Methods We collected species presence–absence data across 70 sites spread between 18 and 27°N in China to analyse the latitudinal diversity gradient in relationship to 25 climate variables. To examine the change in community composition along the diversity gradient, we analysed two components of beta diversity: turnover‐resultant dissimilarity and nestedness‐resultant dissimilarity. We used non‐metric multidimensional scaling to identify crucial climate factors associated with variation in mangrove assemblage composition. We also applied variance partitioning among taxonomic ranks to detect taxonomic signal in climatic tolerance of mangroves. Results First, total species richness decreases with increasing latitude. Second, variation in mangrove assemblage composition is significantly correlated with winter temperature, exhibiting a nested subset structure in species composition and a gradual decrease in the number of thermophilic species with increasing latitude. Finally, mangrove species show a genus‐level signal in tolerance of winter temperature, whereas most other climate factors vary primarily among species within genera. Main conclusions Winter temperature appears to constrain the current distributions of mangrove species, and tolerance of low air temperature is evolutionarily conservative at the genus level. These ecological and phylogenetic patterns collectively suggest that physiological constraints related to cold tolerance structure the nested pattern with respect to the latitude of mangrove assemblages at a regional scale.

Differentiation of Cold Tolerance in an Artificial Population of a Mangrove Species, Kandelia obovata, Is Associated With Geographic Origins

“…Low temperature has been regarded as one of the primary factors affecting the latitudinal range limits of mangrove species (Lugo and Patterson-Zucca, 1977;Duke et al, 1998;Stuart et al, 2007;Ross et al, 2009;Tomlinson, 2016;Osland et al, 2017;Wu et al, 2018). Yang and Lin (1998) showed an increase of cold resistance within K. obovata along latitude.…”

“…Mangroves are temperature-sensitive plants, and thus low temperature may exert strong selective forces on natural populations. Temperature is likely a critical factor in determining mangrove community assemblage and species diversity (Yang and Lin, 1998;Wang et al, 2011;Ruan et al, 2013;Wu et al, 2018).…”

Spatially non-continuous relationships between biological invasion and fragmentation of mangrove forests

“…Conversely, the expansion of mangrove forests in subtropical and temperate regions is limited by its climate conditions, which in turn facilitate the invasion of freeze-tolerant salt marshes (Osland et al, 2017). Another possible explanation of this latitudinal pattern may be that the species richness of mangrove communities may decrease as the latitude rises, weakening the biotic resistance to invaders (Beaury et al, 2020;Guo et al, 2020;Wu et al, 2018).…”

Seasonal atmospheric and oceanographic factors influencing poleward mangrove expansion in the southeastern American coast

“…Low air temperature is considered an important limiting factor for mangrove expansion into higher latitudes at a global scale (Chapman, 1975;Woodroffe and Grindrod, 1991;Quisthoudt et al, 2012;Osland et al, 2017b;Wu et al, 2018). This is explained since the temperature can directly and/or indirectly affect the physiological and phenological processes of the plants (Chuine and Beaubien, 2001;Larcher, 2003).…”

“…Predictions of mangrove range expansion can be improved since refined temperature thresholds for mangrove species frost damage, mortality, or recovery are somewhat better known nowadays (Quisthoudt et al, 2012;Cook-Patton et al, 2015;Osland et al, 2017b;Cavanaugh et al, 2018;Ximenes et al, 2018;Wu et al, 2018;Cavanaugh et al, 2019;Osland et al, 2020a,b;Devaney et al, 2020;Bardou et al, 2021;Chapman et al, 2021;Snyder et al, 2021). Moreover, Santos Borges et al (2019) showed that the germination rate of L. racemosa propagules is below 50% at air temperatures of 10 • C and 15 • C. Reduction in seedling stem elongation rate, altered leaf gas exchange rates, and increased mortality were associated with chilling events at 10 • C especially under high salinity and low humidity conditions (Devaney et al, 2020).…”