Chapter 50: Chapter 50 An Introduction to Ecology and the Biosphere


Slide2: Overview: The Scope of Ecology Ecology Is the scientific study of the interactions between organisms and the environment These interactions Determine both the distribution of organisms and their abundance


Slide3: Ecology Is an enormously complex and exciting area of biology Reveals the richness of the biosphere Figure 50.1


Slide4: Concept 50.1: Ecology is the study of interactions between organisms and the environment Ecology Has a long history as a descriptive science Is also a rigorous experimental science


Ecology and Evolutionary Biology: Ecology and Evolutionary Biology Events that occur in ecological time Affect life on the scale of evolutionary time


Organisms and the Environment: Organisms and the Environment The environment of any organism includes Abiotic, or nonliving components Biotic, or living components All the organisms living in the environment, the biota


Slide7: Environmental components Affect the distribution and abundance of organisms Figure 50.2


Slide8: Ecologists Use observations and experiments to test explanations for the distribution and abundance of species


Subfields of Ecology: Subfields of Ecology Organismal ecology Studies how an organism’s structure, physiology, and (for animals) behavior meet the challenges posed by the environment Figure 50.3a


Slide10: Population ecology Concentrates mainly on factors that affect how many individuals of a particular species live in an area Figure 50.3b


Slide11: Community ecology Deals with the whole array of interacting species in a community Figure 50.3c (c) Community ecology. What factors influence the diversity of species that make up a particular forest?


Slide12: Ecosystem ecology Emphasizes energy flow and chemical cycling among the various biotic and abiotic components Figure 50.3d (d) Ecosystem ecology. What factors control photosynthetic productivity in a temperate grassland ecosystem?


Slide13: Landscape ecology Deals with arrays of ecosystems and how they are arranged in a geographic region Figure 50.3e


Slide14: The biosphere Is the global ecosystem, the sum of all the planet’s ecosystems


Ecology and Environmental Issues: Ecology and Environmental Issues Ecology Provides the scientific understanding underlying environmental issues Rachel Carson Is credited with starting the modern environmental movement


Slide16: Most ecologists follow the precautionary principle regarding environmental issues The precautionary principle Basically states that humans need to be concerned with how their actions affect the environment


Slide17: Concept 50.2: Interactions between organisms and the environment limit the distribution of species Ecologists Have long recognized global and regional patterns of distribution of organisms within the biosphere


Slide18: Many naturalists Began to identify broad patterns of distribution by naming biogeographic realms Figure 50.5


Slide19: Biogeography Provides a good starting point for understanding what limits the geographic distribution of species Figure 50.6


Dispersal and Distribution: Dispersal and Distribution Dispersal Is the movement of individuals away from centers of high population density or from their area of origin Contributes to the global distribution of organisms


Natural Range Expansions: Natural Range Expansions Natural range expansions Show the influence of dispersal on distribution Figure 50.7


Species Transplants: Species Transplants Species transplants Include organisms that are intentionally or accidentally relocated from their original distribution Can often disrupt the communities or ecosystems to which they have been introduced


Behavior and Habitat Selection: Behavior and Habitat Selection Some organisms Do not occupy all of their potential range Species distribution May be limited by habitat selection behavior


Biotic Factors: Biotic Factors Biotic factors that affect the distribution of organisms may include Interactions with other species Predation Competition


Slide25: A specific case of an herbivore limiting distribution of a food species Figure 50.8


Abiotic Factors: Abiotic Factors Abiotic factors that affect the distribution of organisms may include Temperature Water Sunlight Wind Rocks and soil


Temperature: Temperature Environmental temperature Is an important factor in the distribution of organisms because of its effects on biological processes


Water: Water Water availability among habitats Is another important factor in species distribution


Sunlight: Sunlight Light intensity and quality Can affect photosynthesis in ecosystems Light Is also important to the development and behavior of organisms sensitive to the photoperiod


Wind: Wind Wind Amplifies the effects of temperature on organisms by increasing heat loss due to evaporation and convection Can change the morphology of plants Figure 50.9


Rocks and Soil: Rocks and Soil Many characteristics of soil limit the distribution of plants and thus the animals that feed upon them Physical structure pH Mineral composition


Climate: Climate Four major abiotic components make up climate Temperature, water, sunlight, and wind Climate Is the prevailing weather conditions in a particular area


Slide33: Climate patterns can be described on two scales Macroclimate, patterns on the global, regional, and local level Microclimate, very fine patterns, such as those encountered by the community of organisms underneath a fallen log


Global Climate Patterns: Global Climate Patterns Earth’s global climate patterns Are determined largely by the input of solar energy and the planet’s movement in space


Slide35: Sunlight intensity Plays a major part in determining the Earth’s climate patterns


Slide36: Figure 50.10


Slide37: Air circulation and wind patterns Play major parts in determining the Earth’s climate patterns Figure 50.10


Regional, Local, and Seasonal Effects on Climate: Regional, Local, and Seasonal Effects on Climate Various features of the landscape Contribute to local variations in climate


Bodies of Water: Bodies of Water Oceans and their currents, and large lakes Moderate the climate of nearby terrestrial environments Figure 50.11


Mountains: Mountains have a significant effect on The amount of sunlight reaching an area Local temperature Rainfall Mountains


Seasonality: Seasonality The angle of the sun Leads to many seasonal changes in local environments


Slide43: Lakes Are sensitive to seasonal temperature change Experience seasonal turnover Figure 50.13


Microclimate: Microclimate Microclimate Is determined by fine-scale differences in abiotic factors


Long-Term Climate Change: Long-Term Climate Change One way to predict future global climate change Is to look back at the changes that occurred previously Figure 50.14


Slide46: Concept 50.3: Abiotic and biotic factors influence the structure and dynamics of aquatic biomes Varying combinations of both biotic and abiotic factors Determine the nature of Earth’s many biomes Biomes Are the major types of ecological associations that occupy broad geographic regions of land or water


Slide47: The examination of biomes will begin with Earth’s aquatic biomes Figure 50.15


Slide48: Aquatic biomes Account for the largest part of the biosphere in terms of area Can contain fresh or salt water Oceans Cover about 75% of Earth’s surface Have an enormous impact on the biosphere


Slide49: Many aquatic biomes Are stratified into zones or layers defined by light penetration, temperature, and depth Figure 50.16a, b


Slide50: Lakes Figure 50.17


Slide51: Wetlands


Slide52: Streams and rivers


Slide53: Estuaries


Slide54: Intertidal zones


Slide55: Oceanic pelagic biome


Slide56: Coral reefs


Slide57: Marine benthic zone


Slide58: Concept 50.4: Climate largely determines the distribution and structure of terrestrial biomes Climate Is particularly important in determining why particular terrestrial biomes are found in certain areas


Climate and Terrestrial Biomes: Climate and Terrestrial Biomes Climate has a great impact on the distribution of organisms, as seen on a climograph Figure 50.18


Slide60: The distribution of major terrestrial biomes Figure 50.19


General Features of Terrestrial Biomes: General Features of Terrestrial Biomes Terrestrial biomes Are often named for major physical or climatic factors and for their predominant vegetation Stratification Is an important feature of terrestrial biomes


Slide62: Tropical forest


Slide63: Desert


Slide64: Savanna Figure 50.20


Slide65: Chaparral Figure 50.20


Slide66: Temperate grassland


Slide67: Coniferous forest Figure 50.20


Slide68: Temperate broadleaf forest Figure 50.20


Slide69: Tundra Figure 50.20 TUNDRA Denali National Park, Alaska, in autumn