How marram grass or any other species colonisation changes the abiotic conditions

Soil moisture: stabilise the sand dunes by binding the sand particles together with its roots. This increases the soil moisture, as the sand is less likely to be blown away and water is better retained in the soil. Microclimate: They can also modify the microclimate of the sand dune ecosystem, creating a cooler and more humid environment that is better suited to the growth of other plants.