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
- fragmented, pristine, k, early
- fragmented, disturbed, k, early
- fragmented, disturbed, r, early
- unfragmented, disturbed, r, early
- 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.
Step-by-step 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.