 2.d.1 – All biological systems from cells and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy ( ).  2.e.3 – Timing and coordination of behavior are regulated by various mechanisms and are important in natural selection (54.1).  4.a.5 – Communities are composed of populations of organisms that interact in complex ways (54.1 & 54.2).

 4.a.6 – Interactions among living systems and with their environment result in the movement of matter and energy (54.2).  4.b.3 – Interactions between and within populations influence patterns of species distribution and abundance (54.1).  4.c.4 – The diversity of species within an ecosystem may influence the stability of the ecosystem (54.2).

 The study of the interactions between the species in an area

 Interaction between species  May be positive, negative, or neutral  Ex: 1. Coevolution 2. Predation 3. Mimicry 4. Competition 5. Symbiosis

 When two species have reciprocal evolution to each other  Ex: › Flowers and their pollinators

 Predator and prey relationships  Ex – Lynx and Hares

 Often results in interesting defenses or adaptations  Ex: › Plant defenses › Cryptic coloration › Aposematic coloration

 A passive defense where the prey is camouflaged against its environment

 The use of conspicuous colors in toxic or unpalatable organisms to warn off predators Poison Arrow frogs

 Defense mechanism where the mimic has a resemblance to another species, the model  Types: › Batesian › Mullerian

 Palatable species mimics an unpalatable model Hawk moth larva Snake

 Two unpalatable species resemble each other Cuckoo Bee Yellow Jacket

 When two species rely on the same limiting resource  Intraspecific competition usually more severe than Interspecific competition  Why?

 Predicts that two species with the same requirement can not co-exist in the same community  One species will survive and the second will go extinct

 The n-hyperspace of requirements for a species  How a species “fits into” an ecosystem  Species can not have niche overlap; the Competitive Exclusion Principle

1. Fundamental - what a species is theoretically capable of using 2. Realized - what a species can actually use

 A way that species avoid niche overlap by splitting up the available resources  Ex: Anolis lizards

A. distichus A. insolitus

 When two different species live together in direct contact  Types: 1. Parasitism 2. Commensalism 3. Mutualism

 Parasite harms the host  Parasites may be external or internal  Well adapted parasites don't kill the host

 One partner benefits while the other is unchanged  Ex. – Cattle and Egrets

 Both partners benefit from the interaction  Ex: Pollinators and flowers Acacia Tree and Ants

 A keystone species is a plant or animal that plays a unique and crucial role in the way an ecosystem functions. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether.  Prairie dogs are a keystone species in the Great Plains region of the U.S. and Canada Prairie dogs are a keystone species in the Great Plains region of the U.S. and Canada.

 A keystone as an arch's crown secures the other stones in place. Keystone species play the same role in many ecological communities by maintaining the structure and integrity of the community.

 often, but not always, a predator.  A keystone species' disappearance would start a domino effect. Other species in the habitat would also disappear and become extinct. In terrestrial environments, fire ants function as keystone predators by suppressing the numbers of individuals and species of arthropods that could be harmful to agriculture.

 Changes in species composition over time

 Sere: unstable stage usually replaced by another community  rock lichen moss grass shrub tree forest  Climax: stable stage, self-reproducing

1. Primary 2. Secondary

 Building a community from a lifeless area  Ex: volcanic islands glaciated areas road cuts

 Example of primary succession (p. 1209)Glacial retreat

 The first example of primary succession was worked out on the Indiana Dunes  Stages: › Open Beach › Beach Grasses › Conifers (Junipers and Pines) › Oaks › Beech-Maple forest (Climax)

 Where a community has been disturbed and the soil is mostly intact  Ex: › Cutting down a forest › Blow-outs on the Dunes

1. Autogenic Factors 2. Allogenic Factors

 Changes introduced by the organisms themselves  Ex: toxins acids

 Outside disturbances  Ex: Fire Floods

 If you understand the causes and controlling factors of succession, you can manipulate them

 Study of the past and present distributions of individual species and communities

1. Lack of dispersion 2. Failure to survive in new areas 3. Retraction from former range area

 Fossil Evidence  Pollen Studies  Transplant Experiments

 Special cases in Biogeography  Must be colonized from other areas

 Island size  Distance from mainland

 Small islands hold few species  Why?  Fewer niches available for species to occupy

 Closer islands have more species  Why?  Easier for colonization

 Islands tend to have high numbers of Endemic species  Why?  Adaptive Radiation and Evolution of new species

 Identify various types of interspecific interactions.  Identify the Competitive Exclusion Principle and the concept of the Ecological Niche.  Recognize species with a large impact.  Identify the differences between Primary and Secondary Succession and the causes of succession.  Recognize some biogeographical aspects of community diversity.