Competition and Coexistence 18 These methods have provided new formatIsbn:Softcover 9783642430046 These methods have provided new insights into human microvascular function in health and disease The book presents the view that the semantic contribution of tense is made in relation to structurally higher expressions (the `relative tense theory') and argues against the view that tenses are all indexicals Species diversity in local ecosystems has always been discussed in relation to the problem of competi tive exclusion and the apparent contradiction between the competitive exclu sion principle and the overwhelming richness of species found in nature succession