The plants in which vascular tissues are absent and well developed aerenchyma is present, are
Xerophytes
Halophytes
Hydrophytes
Mesophytes
Climax communities
Terai forest is
The maximum biomass of living diatoms to be found in
$A$ : During succession, nutrient availability decreases while biomass level increases.
$R$ : $NCP$ (Net community productivity) remains same during succession.