What role a pioneer species plays during the process of ecological succsession

They begin the process of modifying the environment so that the next organism can come in since they are one of the first organisms to arrive in an area.

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.