Ecosystem services include processes that increase the quality of the abiotic environment. which of the following processes would fall under this category? i) keystone predators have a marked effect on species diversity. ii) green plants produce the oxygen we breathe. iii) the presence of land plants builds soil. iv) the presence of diverse wetlands in flood control. a) only ii and ivb) only i and iiic) only i, ii, and ivd) only ii, iii, and iv

D) only II, III, and IV

Explanation:

Green plants perform the process of photosynthesis. During photosynthesis, splitting of water molecules in the presence of sunlight produces molecular oxygen as a by-product. Plants release oxygen in the air which in turn is used by all the living beings for breathing.

Plants are one of the biotic factors that are involved in the formation of soil. Plants add litter to the ground which in turn is decomposed by the microbes. This adds humus and enriches the soil with organic nutrients. O and A horizons of soil have a higher amount of organic matter.  

Wetland is the region where the transition between land and aquatic ecosystems occur. During excess rainfall, extra water is stored in wetlands. This prevents flooding. This water is sent back to the water bodies later.