Question

Ecosystems in human-dominated landscapes are generally _____ and _____, and support more species with _____ - selected reproductive strategies, and are typical of _____ succession. Group of answer choices

Answer 1

Complete question:

Ecosystems in human-dominated landscapes are generally _____ and _____, and support more species with _____ - selected reproductive strategies, and are typical of _____ succession.

Group of answer choices

1. fragmented, pristine, k, early
2. fragmented, disturbed, k, early
3. fragmented, disturbed, r, early
4. unfragmented, disturbed, r, early
5. unfragmented, pristine, r, early

Answer:

The correct answer is number 3. fragmented, disturbed, r, early.

Ecosystems in human-dominated landscapes are generally fragmented and disturbed, and support more species with r - selected reproductive strategies, and are typical of early succession.

Explanation:

Species have different strategies to survive in different environments, reproduce, disperse, and compete. These strategies are r strategies and k strategies.

• "r" species have a high growth rate per capita, low competition capabilities. This is why they can colonize new environments. But they can not compete with new-established species. "r" species are often displaced by "k" species. These species are mostly small-sized organisms with short life cycles. They reach sexual maturity early and have numerous descendants spending no time or energy in parental care.

• "k" species have a low growth rate per capita, but they are big competitors with the capacity of displacing other species and monopolizing the available resources. These are big-sized species that live for a long time, reaching sexual maturity in advanced stages of their lives. They do not have numerous progenies, but they spend time in parenting.  

r and k strategies are closely related to reproductive strategies, habitat selection, and dispersion ability.

As human-dominated landscapes are generally fragmented and disturbed, new areas are constantly available for r species to colonize them. This is an early stage of succession when these r species arrive in the open perturbated space and colonize it. These r species start a modification in the habitat that makes it suitable for the posterior establishment of later K species. As conditions get better, competition becomes more frequently between species. The first species are eventually eliminated by competition, but new species keep appearing and competing for resources.