Salinity and temperature are both significant abiotic factors affecting biodiversity, with higher salinity leading to lower diversity in freshwater biomes and different temperatures influencing species distribution. Temperate and polar regions have less biodiversity compared to tropical regions.
Step-by-step explanation:
The question asks which variable affects diversity the most within certain environments. Based on the information provided from various contexts, it appears that both salinity and temperature are significant abiotic factors that influence the distribution and diversity of species in aquatic and terrestrial biomes. Higher salinity levels may not be tolerated well by freshwater species, leading to reduced biodiversity, and temperature variations can influence organismal biodiversity due to different metabolic and physiological requirements across species. In temperate and polar regions, there is less biodiversity compared to tropical regions, largely because of differences in temperature and moisture. Additionally, water content, specifically the availability of fresh water versus saline water, can also affect biodiversity, as seen in different aquatic environments like estuaries where salinity varies.