2 Niche is the species ’ occupation and its Habitat location of species (its address)
3Niche A species ’ functional role in its ecosystem; includes anything affecting species survival and reproduction 1.Range of tolerance for various physical and chemical conditions 2.Types of resources used 3.Interactions with living and nonliving components of ecosystems 4.Role played in flow of energy and matter cycling
4Niche Realized niche: more restricted set of conditions under which the species actually exists due to interactions with other species Fundamental niche: set of conditions under which a species might exist in the absence of interactions with other species
5 Types of Species Generalist –large niches –tolerate wide range of environmental variations –do better during changing environmental conditions Specialist –narrow niches – more likely to become endangered – do better under consistent environmental conditions
6 Depending upon the characteristics of the organism, organisms will follow a biotic potential or carrying capacity type reproductive strategy The r-strategists 1.High biotic potential – reproduce very fast 2.Are adapted to live in a variable climate 3.Produce many small, quickly maturing offspring = early reproductive maturity 4.“ Opportunistic ” organisms The K-strategists 1.Adaptations allow them to maintain population values around the carrying capacity 2.They live long lives 3.Reproduce late 4.Produce few, large, offspring r and k strategists
7 Types of Species Native speciesNative species normally live and thrive in a particular ecosystem Nonnative speciesNonnative species are introduced - can be called exotic or alien Indicator speciesIndicator species serve as early warnings of danger to ecosystem- birds & amphibians Keystone speciesKeystone species are considered of most importance in maintaining their ecosystem
8 Nonnative Species Nonnative plant species are invading the nation's parks at an alarming rate, displacing native vegetation and threatening the wildlife that depend on themNonnative plant species are invading the nation's parks at an alarming rate, displacing native vegetation and threatening the wildlife that depend on them At some, such as Sleeping Bear Dunes National Lakeshore in Michigan, as much as 23 percent of the ground is covered with alien species, and the rate of expansion is increasing dramatically.At some, such as Sleeping Bear Dunes National Lakeshore in Michigan, as much as 23 percent of the ground is covered with alien species, and the rate of expansion is increasing dramatically.
9 Indicator Species a species whose status provides information on the overall condition of the ecosystem and of other species in that ecosystem reflect the quality and changes in environmental conditions as well as aspects of community composition
10 Keystone Species A keystone is the stone at the top of an arch that supports the other stones and keeps the whole arch from falling – a species on which the persistence of a large number of other species in the ecosystem depends. If a keystone species is removed from a system –the species it supported will also disappear –other dependent species will also disappear Examples –top carnivores that keep prey in check –large herbivores that shape the habitat in which other species live –important plants that support particular insect species that are prey for birds –bats that disperse the seeds of plants
15Competition Any interaction between two or more species for a resource that causes a decrease in the population growth or distribution of one of the species 1.Resource competition 2.Preemptive competition
17Competition Any interaction between two or more species for a resource that causes a decrease in the population growth or distribution of one of the species 1.Resource competition 2.Preemptive competition 3.Competitive exclusion
19Competition Any interaction between two or more species for a resource that causes a decrease in the population growth or distribution of one of the species 1.Resource competition 2.Preemptive competition 3.Competition exploitation 4.Interference competition
32 Predator Adaptations Prey detection and recognition –sensory adaptations –distinguish prey from non-prey Prey capture –passive vs. active –individuals vs. cooperative Eating prey –teeth, claws etc.
56 Symbiosis: Mutualists, Commensalists and Parasites
57 Symbiosis and symbiotic relationship are two commonly misused terms Translation of symbiosis from the Greek literally means “ living together ” Both positive and negative interactions
58 Mutualism DEFINITION: An interaction between two individuals of different species that benefits both partners in this interaction
59 Mutualism Increase birth rates Decrease death rates Increase equilibrium population densities, Raise the carrying capacity
60 Pollination Animals visit flowers to collect nectar and incidentally carry pollen from one flower to another Animals get food and the plant get a pollination service
61 Yucca ’ s only pollinator is the yucca moth. Hence entirely dependent on it for dispersal. Yucca moth caterpillar ’ s only food is yucca seeds. Yucca moth lives in yucca and receives shelter from plant. Yucca and Yucca Moth
62 Lichen (Fungi-Algae) Symbiotic relationship of algae and fungae…results in very different growth formas with and without symbiont. What are the benefits to the fungus?
63 Nitrogen Fixation Darkest areas are nuclei, the mid- tone areas are millions of bacteria Gram -, ciliate
64 Commensalists Benefit from the host at almost no cost to the host Eyelash mite and humans Us and starlings or house sparrows Sharks and remora
65 Parasites and Parasitoids Parasites: draw resources from host without killing the host (at least in the short term). Parasitoids: draw resources from the host and kill them swiftly (though not necessarily consuming them).
66 Parasitic wasps Important parasites of larvae. In terms of biological control, how would this differ from predation? ovipositor
68 Ecological Succession Primary and Secondary Succession gradual & fairly predictable change in species composition with time some species colonize & become more abundant; other species decline or even disappear.
69 Ecological Succession Gradual changing environment in favor of new / different species / communities
74 Disturbance Event that disrupts an ecosystem or community; Natural disturbance tree falls, fires, hurricanes, tornadoes, droughts, & floods Human–caused disturbance deforestation, erosion, overgrazing, plowing, pollution,mining Disturbance can initiate primary and/or secondary succession
75 Ecological Stability Carrying Capacity – maximum number of individuals the environment can support
76 Ecological Stability - Stress 1.Drop in Primary Productivity 2.Increased Nutrient Losses 3.Decline or extinction of indicator species 4.Increased populations of insect pests or disease organisms 5.Decline in Species diversity 6.Presence of Contaminants
77 Which law directed the Secretary of the Interior to review every roadless area of 5,000 or more acres and every roadless island within National Wildlife Refuge and National Park Systems? A. Endangered Species Act B. Wilderness Act C. Lacey Act D. National Park Act E. Wild and Scenic Rivers Act
78 What are keystone species? A. existing in such small numbers that it is in danger of becoming extinct B. introduced to an environment where it is not native, and that has since become a nuisance C. likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range D. serve as early warnings of damage to a community E. presence and role within an ecosystem has a disproportionate effect on other organisms within the system
79 Who did Roosevelt appoint to head the newly created US Forest Service to protect and manage the world ’ s forests? A. E.O. Wilson B. Aldo Leopold C. Robert MacArthur D. Stephen Mather E. Gifford Pinchot
80 Mutualism benefits: A) one of the organisms & hurts the other B) neither of the organisms C) both of the organisms D) benefits one & doesn’t hurt the other E) only one of the organisms
81 Commensalism: A) benefits only one of the organisms B) benefits both organisms C) benefits one, doesn’t harm the other D) benefits neither of the organisms
82 Biodiversity: A) decreases with speciation and extinction B) decreases with speciation and increases with extinction C) increases with speciation and extinction D) increases with speciation and decreases with extinction
83 What is not a pre-zygotic barriers? A) behavioral isolation B) habitat isolation C) mechanical isolation D) hybrid isolation
84 Which of the following does species richness not depend on? A) rate of immigration B) island size C) distance from mainland D) types of species
85 Which is a species on which the persistence of a large number of other species in the ecosystem depends? A) r-strategists B) k-strategists C) nonnative D) keystone
86 What is not characteristic of a k-strategists? A) long life B) bigger bodies C) produce a lot of offspring D) produce late in life
87 What is not a predator adaptation? A) prey detection B) prey capture C) eating prey D) avoid detection E) mass numbers