Final answer:
Deforestation on a small island primarily impacts ecological and climatic conditions, with consequences like temperature variability, rainfall pattern changes, and reduced biodiversity, potentially leading to an 'ecological meltdown' and affecting agricultural productivity.
Step-by-step explanation:
The primary impact of deforestation on a small island can be considerable, changing various ecological and climatic conditions. First, deforestation can lead to a dramatic loss of forest cover, which is frequently replaced by grasslands or agricultural land. This habitat alteration can have several consequences, including more extreme temperature variability, altered rainfall patterns, and reduced biodiversity. These changes can decrease agricultural productivity due to altered climate conditions like increased dryness or irregular rainfall, which in turn affects local economies and livelihoods. Specifically, deforestation impacts include alterations to the structure and composition of the forest environment, which affect wildlife and could lead to an 'ecological meltdown' where the removal of one species has cascading effects on others. On a small island, the effects could be intensified due to the limited scope for species migration and the high dependency of all biological and human systems on the local environment.