Without further context I would assume the answer here is: Hydroxyl groups.
Answer:
Unwanted/unplanned growth weeds will cover the whole area.
Explanation:
Because the area was previously forested hillside, it has all the environmental conditions (nutrients, rainfall, etc.) to support the vegetation. Hence, Although the soil layer is thin, natural weathering process would increase the depth of soil layer over the years. Later on, biogeochemical cycles on top layer will result into successful nutrients release to support vegetation. Hence, in a few years, there will be growth of weeds (unplanned vegegation).
The pressure would increase. This can be explained by the ideal gas law where for an ideal gas its pressure, volume and temperature is a function of each other ans is expressed by an equation: PV = nRT. We first need to assume that this gas given is ideal. When the temperature and the number of moles is set to a constant value while the volume decreases, we can see that from the equation pressure and volume are indirectly proportional to each other, therefore as the volume decreases, the pressure inside increases.
Answer:
the answer is genetic drifts.
