EcologyMaryland Master Gardeners

University of Maryland Extension

Ecology – the study of how organisms interact with each other and their environment

Photo by Sylvan Kaufman

Scale

Global

Landscape

Ecosystem

Community

Population

Global Processes

Climate change and sea level rise

2006 flood at Adkins Arboretum in Ridgely, MDPhoto by Sylvan Kaufman

Terrestrial Biomes

Image from www.somers.k12.ny.us

Maryland’s Physiographic Regions

Watershed

Image from www.dnr.state.md.us

Land Use in Maryland

Map from www.geog.umd.edu

Connections in the Landscape

Community and Habitat

• Community – The assemblage of all the species in a given area

• Habitat – The physical space providing the environment and resources needed by a population to survive and reproduce.

Great blue heron on a wood duck housePhoto by Sylvan Kaufman

Niche

• Niche – all of the specific environmental conditions and resources required for it to maintain a viable population.

Beans, swiss chard and alyssum

Photo by Sylvan Kaufman

Creating microclimates• Microclimate – climactic variation on a scale of

a few miles to a few inchesSlopeAspectElevationVegetation

Fallen logsBouldersBurrowsWaterGround color

Photos by Sylvan Kaufman

Water

Energy and Nutrients

PhotosynthesisCarbon dioxide + water → sugar + oxygen

Monarch caterpillar on butterfly milkweed

Photo by Sylvan Kaufman

Physiology

• How organisms carry out physical or chemical functions in the environment

Functional Groups

rabbits

Grouping by Interaction

Pollinators

Mycorrhizae

Dispersers

ParasitePhotos by Sylvan Kaufman and from www.wikipedia.org

Native Pollinators

Photo by Sylvan Kaufman; other photos www.wikipedia.org

Succession

Photos by Sylvan Kaufman

Disturbances

Photo from bugwood.orgPhoto from NASA

What is a species?

Sciurus caroliniensis, Eastern grey squirrel

Tamiasciurus hudsonicus, red squirrel

Sciurus niger cinereus, Delmarva fox squirrel Photos from

wikipedia.org

Evolution

Image from biologyonline.org

Natural Selection

• Variation in traits among individuals in a population

• Characteristics are heritable - have genetic basis

• Ancestors leave different numbers of descendants based on interactions between the traits of the individual and its environment.

Genes

Image from exploringnature.org

Gene flow

Seeds

Rhizomes

Pollen

Photos by Sylvan Kaufman

Populations and Life History

Photo by Sylvan Kaufman

Plant Breeding

Photos from wikipedia.org

Straight species, cultivars, hybrids

Echinacea ‘Art’s Pride’E. purpurea x E. paradoxa

E. purpurea ‘Magnus’

Echinacea purpurea

Echinacea paradoxa Photos from Missouri Botanical Garden PlantFinder

Genetically modified organisms (GMOs)

Ad for Roundup Ready corn for Phillipines from Pioneer.com

Rare Plants

Pink coreopsis, Coreopsis roseaPhoto by Sylvan Kaufman

Ecosystems

• Energy• Water• Biogeochemical – C and N

Energy flow through ecosystems

Food Webs

Image from exploringnature.org

Carbon Cycle

Image from physicalgeography.net

Human influences on C Cycle

Image from www.cmdl.noaa.gov

Consequences for Gardeners

• Initially more rapid plant growth until other resources (water, nutrients) limit growth

• Greater production of ragweed pollen• Greater toxicity in some plants like poison ivy• Shifts in plant ranges

The Hydrological Cycle

Image from physicalgeography.net

Effects of Development on Water Cycle• Increased surface area runoff (10 – 20% rural, 60-

70% urban)

• Decreased groundwater recharge• Increased use of groundwater• More rainfall reaches the ground• provision of man-made drainage systems (e.g.,

storm sewers, channels, detention ponds).

The Nitrogen Cycle

Image from physicalgeography.net

Terms used in the N Cycle

• Nitrogen fixation – conversion of gaseous N (N2) to solid forms of N (NH3) through biological processes (bacteria), lightning, and chemical processes

• Ammonification – conversion by bacteria of N from decaying organisms into ammonia (NH3)

• Nitrification – conversion by bacteria of ammonia (NH3) to nitrites (NO2) and nitrates (NO3)

• Denitrification – conversion of nitrate (NO3) to gaseous N (N2) by anaerobic bacteria

Human influences on N Cycle

• Increase in fixed N through production and application of chemical fertilizers and growing leguminous crops (e.g. soybeans)

• Nitrogen enrichment of soils from atmospheric N deposition, application of fertilizer, manure

• Increases in nitrate flow in streams and nitrous oxide losses to atmosphere through land clearing, deforestation

• Eutrophication (over-fertilization) of lakes• Animal husbandry releases ammonium to atmosphere• Release of nitrous oxides from oil and coal combustion

contributes to acid rain

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Biodiversity

The Highline in NYC converts an old elevated railway to a native plant garden and walkway

Photo by Sylvan Kaufman