Definitions

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Fruit Types

  • Berry – Wall (except epidermis) entirely flesh; one or more seeds (eg: Asimina, Solanum, Vitis)
  • Pome – Inner wall papery (core); outer wall fleshy, from receptacle; many seeds (eg: Amelanchier, Aronia, Malus, Pyrus)
  • Drupe – Inner wall forming a stone; usually one seed (eg: Prunus, and most berries)
  • Achene – Hard waled; usually less than 0.4 mm (eg: Platanus)
  • Nut – Hard-walled, usually more than 0.5 mm (eg: Fagus, Quercus, Carpinus)
  • Samara – Possessing an airfoil outgrowth of ovary wall (eg: Acer, Fraxinus, Ulmus)
  • Follicle – One carpel; splits along its two sides (eg: Spiraea, Magnolia)
  • Legume – One carpel, splits along two sides (eg: Cercis, Gleditsi, Robinia)
  • Capsule – Two or more carpels fused, splits variously (eg: Catalpa, Populus, Salix)
  • Aggregate – Composed of fruits from a single flower (eg: Rubus)
  • Multiple – Composed of fruits from many flowers in a head or spike (eg: Liquidam, Morus)

Vegetative Reproduction

  • Root Collar – New stem at juncture of trunk and root (eg: Quercus, Tilia)
  • Roots – Root suckers, xylem (eg: Fagus, Populus (aspens, not cottonwoods)
  • Rhizome – Underground stem, pith (eg: Cornus foemina)
  • Runner – Creeping stem along soil surface (eg: Euonymus obovatus)
  • Stolon – Arching stem takes root (eg: Decodon verticillatus)
  • Layering – Lower branches take root (eg: Picea mariana)
  • Tipping – Tree falls and branches become erect stems (eg: Thuja occidentalis)
  • Fragmentation – Broken off stem pieces take root (eg: Salix, Populus, Deltoides)

Landscape Features

  • Moraine – A general term for a ridge or mound of till deposited by a glacier
  • Terminal Moraine –A moraine found near the terminus of a glacier; also known as an end moraine
  • Ground Moraine – A continuous layer of till deposited beneath a steadily retreating glacier
  • Lateral Moraine – A moraine deposited along the side of a valley glacier
  • Kame – A steep-sided, conical mound or hill formed of glacial drift that is created when sediment is washed into a depression on the top surface of the glacier and then deposited on the ground below when the glacier melts away
  • Kettle – A shallow, bowl-shaped depression formed when a large block of glacial ice breaks away from the main glacier and is buried beneath glacial till, then melts. If the depression fills with water, it is known as a kettle lake
  • Crevasse – A deep, nearly vertical crack that develops in the upper portion of glacier ice
  • Esker – A long, snakelike ridge of sediment deposited by a stream that ran under or within a glacier
  • Glaciation – The transformation of the landscape through the action of glaciers
  • Glacier – A large body of ice that formed on land by the compaction and recrystallization of snow, survives year to year, and shows some sign of movement downhill due to gravity
  • Glacial Drift – A general term for all material transported and deposited directly by or from glacial ice
  • Till – A random mixture of finely crushed rock, sand, pebbles, and boulders deposited by a glacier

RAVE

  • Q. Rubra – Wet/Mesic
  • Q. Alba – Mesic
  • Q. Velutina – Dry/Mesic
  • Q. Ellipsoidalis – Dry

Soil - The following notes were taken during a guest lecture by Dr. Don Zak
See CTools > Resources > Guest Lectures for the full handout

  • A dynamic natural body composed of mineral matter, organic matter, gases, and living organisms in which plants grow
  • The collection of natural bodies occupying the Earth’s surface that support plants and have properties due to the integrated effects of climate and living organisms acting upon mineral material, as conditioned by relief, over periods of time

Factors Influencing Soil Formation

  • Climate – Temperature and precipitation
  • Living Organisms – Animals, plants, and microorganisms
  • Parent Material – Physical and chemical properties of geologic materials
  • Topography – Landform, slope, and aspect
  • Time – Duration over which climate and living organisms have influenced parent material

What Controls the Geographic Distribution of Ecosystems

  • Regional Climate – Broad-scale patterns of temperature and precipitation
  • Geology – Elevation, slope, aspect, and soil parent material
  • Local Climate – Temperature and precipitation

Soil Layers

  • 0 Horizon – Leaf litter
  • A Horizon – Topsoil
  • B Horizon – Subsoil
  • C Horizon – Parent material

Plant Communities are tied to Microbial Communities

  • Plant litter biochemistry
  • Substrate availability
  • Soil nitrogen availability
  • Environmentally similar conditions (eg: temperature, water potential, pH)

(end of guest lecture)

Photosynthesis – The process by which green plants use light to synthesize organic compounds from carbon dioxide and water

  • Photosynthetically Active Radiation – PAR
  • Saturation Point – Point at which increases in light no longer increase enzyme activity (In fact, the added radiation may destroy plant material, decreasing photosynthesis)
  • Compensation Point – Point where the rate of photosynthesis matches the rate of respiration

Plant Strategies

  • Sunflecks – Phototrophic plants can seek out canopy gaps, growing fast to outcompete other species
  • Low Compensation Points – These plants will be shade tolerant and able to survive in the understory
  • Seasonal Growth – In temperate climates it is beneficial to take advantage of the short but strong growing season
  • Seedling Banks – This ensures that a species will have a competitive advantage if a gap opens up
  • Shade vs Light Leaves – Shade leaves are thinner and broader, sun leaves are thicker and narrower

Shade Tolerance – High survival, slow growth
Light Demanding – Low survival, rapid growth
Mechanisms of Freezing Resistance

  • Freezing avoidance
    • Avoidance of freezing temperature
    • Avoidance of ice formation
      • Avoidance of intracellular freezing
      • Avoidance of any freezing
  • Absence of freezable water
  • Supercooling
  • Freezing tolerance
    • Tolerance of intracellular freezing
    • Tolerance of extracellular freezing
      • Avoidance of freeze dehydration
      • Tolerance of freeze dehydration

What is a Vine - The following notes were taken during a guest lecture by Dr. Robyn Burnham
See CTools > Resources > Guest Lectures for the full handout

  • Not self supporting, but often woody (ie: a liana)
  • Rooted in the ground
  • Climbs from initial rooting position to canopy with little investment in wood

The Consequences of the Climbing Habit

  • Rapid growth
  • Dependence on supporting structure
  • Innovations in climbing technique
  • Stems break due to support collapse
  • Uncontrolled stem movement and swinging, causes air bubbles in xylem (cavitation)

Vines, Lianas, and Climbers – Don’t worry about specifics of definitions but many people consider vines to be entirely herbaceous and lianas to be entirely woody
Climbing Mechanisms

  • Defined according to the modified organ (ie: leaf, stem, root)
  • Defined according to the type of structure ultimately produced (ie: tendril, sticky holdfast, stem coils, etc)
  • 90% of stem twiners coil from left to right, the big exeptions are Dioscoreaceae (wild yams) and Asteraceae (daisy and sunflower relatives)

Phylogenetic Considerations

  • Where did vines come from
  • How long have they been on Earth
  • Did they all come from the same vine ancestor – no all different areas (eg: fern, gymnosperm, etc)

Geographic Distribution of Climbers

  • Climbers are more numerous and more diverse near the equator where it is warmest and wettest
  • Climbers can be very susceptible to xylem collapse – freezing, hard knocks, swinging, breaking can all cause xylem bubbles and subsequent collapse
  • Although climbers are sensitive to frost, similar patterns appear when compared to other life forms – 25% of woody plant diversity, 5-10% of density both by region and individual sites

Vines under regimes of Disturbance and Global Change

  • Regional studies suggest vines may be increasing in size, relative to trees
  • Controlled studies suggest that Poison Ivy vines are more virulent and more vigorous with increased CO2
  • Other studies suggest that vines have responded more to disturbance in the last 50 years than to increases in global CO2, however we have little information on most areas and most species

Common Recognition Characters to Note when you find a Woody Climber

  • Opposite or Alternate
    • Opposite – Lonicera, Euonymus
    • Alternate – Vitis, Smilax, Parthenocissus, Celastrus, Toxicodendron
  • Tendrils, Apical Twining, or Root Climber
    • Tendrils – Smilax, Vitis, Parthenocissus
    • Apical Twining – Celastrus, Lonicera
    • Root Climber – Toxicodendron, Euonymus, Parthenocissus
  • Serrate or Entire
    • Serrate – Vitis, Parthenocissus, Celastrus, Toxicodendron
    • Entire – Lonicera, Euonymus, Smilax

(end of guest lecture)

Dormancy

  • Dry Seeds – Dehydration of seed – Quiescence
    • Sow in moist environment
  • Seed Coat Dormancy – Hard seed coat impermeable to water and gases – Quiescence
    • Scarification – Physical or chemical abrasion of seed coat
  • Embryo Rest – Low growth promoters and/or high growth inhibitor in embryo – Rest
    • Stratification – Cold (35-40 F) moist storage for 4-12 weeks
  • Double Dormancy – Hard seed coat plus embryo rest – Quiescence and Rest
    • Scarification then stratification
  • Chemical Inhibitors – Inhibitors in pericarp (fruit wall) or testa (seed coat) – Correlative inhibition
    • Remove fleshy pericarp or testa
    • Leach in running water is pericarp or testa is dry
  • Immature Embryo – Underdeveloped or rudimentary embryo dormancy – Developmental
    • After ripening, store for t weeks under ambient conditions
    • Warm stratification, moist storage
    • Embryo culture
  • Light Requirement – Phytochrome in Pr form – Secondary dormancy
    • Expose to any white light
    • Expose to red light
    • Sow shallow or on surface

Stages of Seed Germination

  • Phase I – Imbibition, protein activation, protein synthesis, respiration begins
  • Phase II – Protein synthesis and metabolic activation continues, digestion of stored food reserves, translocation of digested reserves begins
  • Phase III – Radicle emerges, reserves mobilized, cell division, expansion and growth

Field Lab Sites

  • Miller Woods – End moraine
  • Radrick Forest – End morain to outwash plain
  • Waterloo – Ground moraine with kames
  • Haven hill – Ground moraine with kames and kettles

Other Terms

  • Deciduous – Loses leaves seasonally (vs: evergreen)
  • Decurrent – Spreading branch pattern (wide vs: excurrent – grows tall and conical)
  • Photostropism – Growth response toward light
  • Determinate Shoots – Shoots that extend and set buds early in the growing season
  • Indeterminate Shoots – Continue to grow during the entire season, early leaves develop near base, and late leaves develop at the apical end
  • Early Leaves – Leaves developing early in the growing season, buds develop in previous year
  • Late Leaves – Develop during the latter part of the growing season
  • Shade Leaves – Lower and interior leaves, thinner, broader
  • Sun Leaves – Upper and exterior leaves, thicker, narrower
  • Lenticels – Rupture in a twig, helps facilitate gas exchange
  • Ecodormancy – Signaled by environment (eg: cold, fire, light, etc)
  • Endodormancy – Signaled by physiology
  • Photodormancy – Signaled by light (day length)
  • Prickles – Non-vascular, easily broken off
  • Spines – Modified leaves, containing vascular tissue
  • Thorns – Modified branches, containing vascular tissue

Disturbance

  • In general, disturbance maintains diversity by providing variation within the landscape

Factors to consider

  • Scale - regional, local, microsite (scale varies)
    • Regional - ice storm, hurricane, pests, drought
    • Local - fires, landslides, tornadoes, flooding, wind
    • Microsite - gopher hole, tree fall (important for species that seed in bare soil)

Fire

  • Frequency
  • Type - varies mainly by ecosystem type
    • Ground - Burns grasses and ground cover, seen in savanna ecosystems
    • Surface - higher intensity, burns the understory but not crowns
    • Crown - Burns all the way to the crown of the tree, almost all of the tree is damaged, maybe even the organic matter
  • Intensity - how hot or long does the fire burn
    • Commonly measured in the west
    • Will change with global climate changes
  • Timing - before budding, after, very important
  • Fuel - dry deadfall vs live vegetation
  • Climate - humid vs dry
  • Topography - mountainous vs hilly vs dry
  • Soil water - wet vs dry
  • Wind speed - high speed vs low

Effects of Fire
*Occurs in most ecosystems (not really swamps)

  • Helps shape pine and oak ecosystems
  • Key on many different levels
    • Recruitment - influences light regime
    • Microsite - removes litter layer
    • Competition - by destroying some species and not others
    • Nutrients - causes a flash of certain nutrients
      • May drastically increase nutrient cycling in areas where decomposition is generally slow (outwash or cold sites)
    • Pests
      • May be killed during the fire
      • May promote later outbreaks by creating a forest composed of trees of similar age
    • Succession
      • Primarily of fire resistant species
      • Some species only germinate after fire
    • Biodiversity
      • Fire creates a mosaic in the landscape

Examples of fire dependent species

  • Longleaf pine in the SE
    • Grows to a grass stage where the terminal bud of the stem is covered by long dense needles
    • Fire burns everything else away, and the needles, but the terminal bud is left
    • The tree grows very fast afterwards (up to 2 m) so that the next fire won't affect it
    • Note: longleaf pine can't live in Michigan because the weight of snow is too great for the long needles to bear
    • In Saginaw Forest, many different species were planted, but only those with shorter more robust leaves have survived
  • Douglas fir in the Pacific NW
  • Sequoias in California
  • Jack pine in the Great Lakes region
  • Lodgepole and Ponderosa pine in the west

Effects of Fire

  • On Soils
    • Loss of organic matter
    • Speeds mineralization
    • Increases erosion (no vegetation)
    • Reduces moisture
    • Allows more extreme temperature fluctuations
    • Decomposition is accelerated
    • pH increases
    • Changes in nutrients (some more available, some less)
    • Soil animals and microbes will be affected (changes in habitat)
  • Plant adaptations
    • Avoid damage (thick bark, dense needles around buds)
    • Recover (from rhizomes or roots, example: aspen)
    • Coonization (good dispersers that need bare soil, example: birch)
    • Promote fire (example: paper birch) because it will promote regeneration of new individuals
  • Animals
    • Initial evacuation
    • Changes habitat availability (fire may promote shrublands, good for bird nesting)
    • Changes food availability (fire may allow grasses to grow better, good for grazers)
  • On ecosystem processes
    • Energy flow increases
    • Decomposition increases
    • Primary productivity initially depressed
    • Changes in nutrient availability
    • Carbon storage
      • GPP (Gross Primary Production) - Photosynthesis
      • PR (Plant Respiration) -
      • HR (Heterotrophic Respiration) -
      • NEP (Net Ecosystem Productivity) - NEP = (Carbon fixed by GPP) - (Carbon lost by PR) - (Carbon lost by HR)
      • We may want to manage an ecosystem to maximize NEP (to optimize harvesting or carbon sequestration)

Strategies of Species Persistence

  • Seed Based
    • Invaders - Betula and Populus (wind dispersed over large areas and germinate well on bare soil)
    • Evaders - Pinus banksiana (cones close with resin, high temperatures melt resin and release seeds)
    • Avoiders - Late successional species - Fagus, Abies basalmea, Picea glauca
  • Vegetative Based
    • Resisters - Pines and Oaks (thick bark)
    • Endurers - Betula and Populus (root are less likely to be damaged and will be able to sprout after fire)

Community - Species Interactions

  • Symbiosis - both organisms benefit (or one benefits, neutral for the other)
    • Mutualism
      • Mycorrhizal
        • Ecto (fungi hyphae sheathe the outside of roots)
        • Endo (fungi hyphae invade the roots)
        • Fungi extract water and minerals from the soil and move those nutrients to the plant roots
          • Hyphae may connect plants together improving survival of small plants in the forest floor
        • Plants experience increased nutrient uptake
        • Fungi may produce plant hormones
        • Fungi die off in winter and must be formed again each year
        • Fungi reduce competition because they are benefiting many individuals
        • May improve soil aeration
      • Nitrogen fixing
        • Species within Fabaceae - Ex: Robinia - use Rhizobium to help them fix nitrogen
        • Very competitive in nutrient poor areas, but they need to be able to photosynthesize a lot of carbon
          • They need a lot of light
      • Insect pollination
      • Seed dispersal
    • Commensalism
      • Epiphytes - grow on top of other plants
      • Lianas
  • Antagonistic -
    • Non-consumptive physical exploitation
      • Lianas - Ex: Kudzu - introduced to the South and moving north
        • Causes damage because of weight or preventing photosynthesis by the plant underneath
    • Consumptive exploitation
      • Parasitism - Chestnut blight (fungi), Dutch elm disease (fungi), Hemlock wooly adelgid (insect), mountain pine beetle in Alaska
        • Global trade is introducing pests to new areas where trees are not adapted to deal with them
        • Global warming is improving conditions for many of these pest species
      • Predation (of seeds)
        • Some are adapted to being eaten, but not all
        • Masting is a strategy to increase regeneration
      • Herbivory
        • Plants attempt to combat herbivory by producing chemicals like tannins
    • Antibiosis
      • Allelopathy (Ex: Juglans, P. serotina) - produce chemicals to inhibit growth in the soil around them
      • Competition (for resources)
        • Intraspecies - within a species
        • Interspecies - between species

Mycorrhizae
Biogeographic History

  • The last glaciation occurred about 20 kya
    • The Laurentine ice cap - Wisconsin glacier - during the Holocene epoch
      • This left topographic features - ground and end moraines, outwash plains and lake muck
  • Who studies historic biogeography? - Paleoecologists
    • Macrofossils - fossilized plants - pretty rare
    • Microfossils - Palyoogy - the study of pollen fossils
      • We can identify pollen grains, maybe not to species, but at least family or genus
      • Lakes are good places to get a pollen record
        • Every year, plants produce pollen, and it lands on a lake
        • The pollen settles to the bottom through the year
        • The next year the same thing happens and if it isn't disturbed much, you will find a stratified system of layers of pollen
        • Cores are extracted and analyzed
        • Line don't reflect years (like tree rings) so Palynologists need to date the strata
          • C14 (half life: 5730 years) dating is used to date layers
          • You compare the amount of C14 in fresh pollen to the amount in the layer of interest and can calculate the age
        • Final product of a pollen study is a pretty pollen record
          • Caveats - Wind pollinated species may be well represented, but animal pollinated species may not be
          • If all you know is there were lots of Quercus species, you don't know anything about specific site conditions since they are adapted to a wide range
          • Some species may produce lots of pollen while others produce very little
  • 22-15 kya - Tundra and Boreal forest extended much farther than today - everything else was pushed much farther south
    • Tundra - open treeless community of grasses, herbs, and low shrubs
    • Boreal Forest (Taiga) - Dominated by conifers
      • North
      • South
    • South - Narrow belt of mixed conifers and northern hardwood forest - white pine, red pine, hemlock, spruce, fir, oak, ash, maple, beech
    • Far South (Florida-ish) - Longleaf pine, bald cypress, nyssa, southern pines
    • Refugia - Areas with unique conditions that allow certain species to persist in a limited range, then when climate shifts, those species have an advantage because they may already be close by - Hemlock, Oak, Walnut may have been in refugia to the east or west of Michigan
    • We are still not certain about migratory rates of trees - the pollen record is confusing and conflicting
      • Perhaps there were many more refugia than we first though
      • Migration rates depend on whether they wind or animal dispersed - why would a squirrel carry an acorn into the tundra?
        • Scientists would expect wind dispersed species to spread faster, but the pollen record shows that animal dispersed species migrate faster
      • Dry Spell (4500-3500 BP) - Slowed some species - Beech and Hemlock
      • Little Ice Age (1400-1800) - Also affected some migration patterns

River Flood Plain

  • Periodic flooding - if it happens during the dormant period, many trees can tolerate it
    • Aeration mechanisms - air holding tissue in the stems or roots, lenticels help absorb oxygenr, adventitious roots are grown to absorb oxygen
    • Many species spread seeds in spring and germinate quickly taking advantage of moist conditions
  • Bank cutting by streams causes constant changes
  • Particle deposition by standing and running water results in a dynamic ecosystem
  • Four Zones
    • Flood plain - the area that is frequently flooded - sometimes during the growing season - Salix, B. nigra, P. deltoides
    • Terraces - major differences are how frequently they are flooded and how close they are to the water table - A. saccharinum, F. pennsylvanica, U. americana, P. occidentalis
      • Higher up - less flooding - G. dioucus, C. occidentalis, A. triloba
    • Upland - no flooding, drier - A. saccharum, F. grandifolia, F. americana, P. serotina, Q. rubra, Q. velutina

Fire Part II - The past 300 years

  • What determine's species composition in space and time?
    • Disturbance - small (treefall) to large (pest outbreaks, hurricanes) shapes forests

Presettlement (European) Forests

  • Thomas Jefferson enacted a campaign to survey our forest resources after the Revolutionary War (to pay our huge debt)
    • Every square mile would be broken up into 4 quadrats
    • Foresters went out and surveyed before pioneers went in and reshaped the vegetation

Fire in Presettlement Forests

  • Causes - lightning causes about 50,000 fires per year (in the US?
  • Alternatively, Native Americans started them
    • To manage the land to benefit herbivores - which they hunted
    • To manage malaria by preventing dense understory vegetation, thus cool damp habitat
  • Properties of Wildfire
    • Intensity, and frequency (more frequent in savannahs, every year vs. less frequent in forests, every decade or so)
    • Types of fire
      • Surface fire - burns through understory
      • Ground fire - smolders in organic layers
      • Catastrophic fire - generates its own wind, devastates the forest
      • Crown fire - burns upper layer of trees
    • Tree rings can tell about fire (dendrochronology) - Charcoal in the soil can also shed light on historic fires
    • Fire dependent ecosystems
      • Chapparal - shrubby vegetation in the west
      • Grassland and prairie
      • Boreal forest
      • Oak opening - Oak savannah
        • Transition between prairie and forest
        • White, bur, and black oaks - hazelnut - and lots of herbaceous species
        • These are pretty much gone in Michigan - agricultural clearing, fire supression
      • If you take the fire away, trees will grow in many of these areas - fire keeps them out
  • Adaptations to fire
    • Thick insulated bark - cork
    • Rapid juvenile growth, being tall protects the meristem - pines
    • Underground buds and rhizomes - deep roots, bole buds, root collar meristems
    • Flammability - short stature (jack pine), foliage and bark (pines, paper birch), retention of dead branches (pin oak)
    • Colonization - light wind-borne seeds (betula, populus, salix), serotinous cones (jack pine), heat induced germination (rhus)

Fire in Postsettlement Forests

  • Harvested the best 1/3 of the bole in many cases - Hemlock was harvested only for bark
    • 100-200 tons of wood was left on the ground
  • Coal fired trains were used to transport materials
  • Everyone used fire in the daily life
  • Wind stirs these fires up and they begin to spread
  • Logging removed many of the seed producing trees, and fire destroyed the rest
  • The result was a regime of fire supression
  • This allows novel forest types to grow
    • Red maple is moving into dry upland sites where it wasn't historically found, because fire is suppressed and can't eliminate it

Boreal Forests and Taiga

  • Physiognomy is uniform - same species throughout
    • Picea glauca and Picea mariana - white and black spruce - found commonly throughout
    • Larix laricina, Abies basalmea, Pinus banksiana, and Pinus contorta - also found commonly
    • Populus tremuloides, P. basalmifera, B. papyrifera - found in the boreal forest
  • Boreal Forest
    • 50-60 degrees North -up to 70 degrees depending on climate conditions
    • Growing season is at least 120 days
      • The short growing season is one of the primary limiters of other species moving in
    • Species here must be cold tolerant
    • Drivers
      • Climate - micro/topoclimate
        • Boreal forest exists between the July isoclines between 13-18 degrees C
      • Geology and glacial history - not as significant as topography
      • Topography
        • Alluvial deposits - Picea glauca dominates
        • Upland bedrock - Picea mariana dominates
        • Peat - Picea mariana dominates
      • Soil - Primarily spodosols
        • Accumulation of organic matter on top, not being decomposed
        • A light layer material where nutrients are being washed down
        • A dark layer below (the B horizon) where the nutrients accumulate
        • Formed in areas with low temperatures and low precipitation
        • There is an excess of water in these soils because temperatures are low (ie: evaporation is low)
        • Permafrost is also prevalent
        • Boreal soil is relatively acidic
    • Even with flat topography, there will still be many different communities - this has to do with microtopography
      • Differences in the level of the water table will affect the vegetation - even if the differences are just a few cm

North American Boreal Forest

  • Alaskan Taiga
    • P. glauca, P. mariana, B. papyrifera, P. tremuloides
      • The species from Betulaceae indicate that fire is prominent in this region
  • Northern Rocky Mountains
  • SW of Northwestern Territories - Northern Alberta
    • P. banksiana, P. tremuloides, P. basalmifera, P. glauca, P. mariana, P. contorta - Again, fire is important to maintain some of these species
  • W-E Hudson Bay
    • Uniform species composition
    • (north) P. mariana »> P. glauca »> P. banksiana (south)
  • Gare-Maritime Area (Eastern Quebec)
    • Influenced by the Atlantic Ocean
    • Abies basalmea - indicating low disturbance caused by fire
  • Labrador Ungava
    • P. mariana, P. glauca, Abies basalmea, Larix laricina, B. papyrifera
  • North Forest Line
    • Picea mariana
    • More of a park-like type of vegetation
    • There are still other species, but they will only be common in microclimate areas that are more suitable to them
  • Disturbance in the Taiga
    • These are young forests - fire is recurrent and regular
    • Succession in the far north
      • Increase in the thickness of the organic matter
        • Acidic soils and prevalent moisture result in low decomposition - locking a lot of carbon and nutrients in the soil
      • Decrease in nutrient availability
        • Low decomposition keeps nutrients in the organic matter and prevents it from being released to new growth
      • Decrease in summer soil temperature
        • Shading cools the ground and decreases the temperature
        • Low temperature also contribute to suppressing decomposition because microbes are less active
      • Increase in permafrost level
        • Shading by vegetation cools the ground
      • Decrease in soil draining
        • Low temperatures and low decomposition both contribute to low drainage
      • Increase in forest diseases
    • Fire adaptation
      • Populus basalmifera - fire resistant: thick bark, sprouts
      • P. banksiana, contorta, mariana - fire evaders: serotinous cones (fire causes resin to melt and seeds are released) - fire resistant: thick bark
      • P. tremuloides - fire endurer: sprouting
      • A. basalmea, P. glauca - late successional: not well adapted to fire, only appear after a long period without disturbance
    • Pests are another important type of disturbance (to be covered in another lecture)
    • Logging is also prevalent
      • Sustainable logging is possible in these ecosystems - but this is not being practices
      • In Canada, logging is taking place at levels 30% above what is sustainable
      • Disturbance is not bad in some cases, but logging is taking place on a much larger scale - clearcutting in a lot of cases
      • These soils are young - they only began developing after the last glaciation (~10-20 kya)
        • After logging, these communities are slow to recover because the soil is not well developed

Temperate Deciduous Forests

  • Eastern United States, Europe, East Asia, East Australia
  • Many of the trees in other parts of the world are from the same genuses
  • In the United States - They extend from N. Florida to ~Canada
  • Air masses in North America
    • Continental Polar (cP) - cold,dry - formed in Canada and Alaska
    • Maritime Tropical (mT) - warm, moist - formed in the Gulf and equatorial Atlantic
    • Maritime Polar (mP) - cool, moist - formed in the North Pacific, loses its moisture before the Sierras
  • Boundaries of Eastern US Temperate Forests
    • Hardiness zone - based on the average minimum temperature in an area
      • Southern Michigan is in zone 6, Florida, for instance, is in zone 9/10
    • North: -40F average minimum temperature, and growing season is too short
    • South: Lack of extreme chilling, not enough cold to break dormancy - not enough cold to tell them winter is over
    • West: Lack of precipitation
  • Temperate Forest Characteristics
    • Winter is cold, but not too cold
    • Growing season at least 4-6 months
    • Precipitation is even during the growing season
    • Major genus: pine, quercus, acer, fagus
    • Light limitation is key to determine the composition of specific forests
  • Braun's Forest Regions
    • Mixed mesophytic
      • Cumberland and Allegheny Mountains
      • Was a glacial refuge during the last interglacial - rich with species
    • Western mesophytic
      • Cumberland and Allegheny Mountains (plateaus)
      • Xeric »> Mesic
      • J. virginiana, P.echinata, Q. stellata, Q. alba, Q. prinus, Q. rubra, F. grandifolia, A. saccharum
    • Oak-hickory
      • Ozarks
      • South: Q. stellata, Q. marilandica, Q. shumardii, C. texana
      • North: Q. macrocarpa, Q. ellipsoidalis, Q. velutina
      • Throughout: Q. alba, Q. rubra, Q. velutina, C. cordiformis, C. ovata
    • Oak-chestnut
      • Appalacians 400m - 1400m
      • C. dentata, L. tulipifera, Q. prinus, Q. rubra, Q.alba, Q. coccinea
    • Oak-pine
      • Piedmont
      • P. taeda, P. echinata
      • High moisture and fertile: Liquidambar, L. tulipifera, P. occidentalis, C. caroliniana, F. grandifolia, U. rubra, A. rubrum, F. pennsylvatica, Q. alba, Q. rubra, F. americana, A. saccharum
      • Dry and fertile: Q. stellata, Q. alba, Carya, Cercis canadensis, F. americana
      • Dry and poor: Q. prinus, Oxydendrum arboreum, Q. alba, Q. coccinea, A. rubrum, C. tomentosa
      • Special cases - wet/dry (clay) - like Lawrence Woodlot
        • Q. phellos, U. alata, Fraxinus, C. ovata, Q. stellata, Q. marilandica, P. taeda, P. echinata
    • Southern evergreen - skipping for now - saved for next lecture
    • Beech-maple
      • Southern Michigan - Like Miller Woods
      • F. grandifolia, A. saccharum
    • Maple-basswood
      • Western Wisconsin, Eastern Minnesota
      • A. saccharum, T. americana
      • The area is generally, dominated by fires, but in this region, ther are lots of fens and bogs which suppress fire, allowing late successional species to grow
    • Hemlock-white pine-northern hardwoods
      • Wet conditions: Hemlocks
      • Dry conditions: White pine
      • Fertile mesic: F. grandifolia, A. saccharum
    • Special cases - wet/dry (clay) - like Lawrence Woodlot
      • Q. phellos, U. alata, Fraxinus, C. ovata, Q. stellata, Q. marilandica, P. taeda, P. echinata
    • Disturbances
      • Fire, windstorms, ice storms, pests, and humans
      • Humans - cultivation, pasture, logging - results in fragmentation
        • Fragmentation - increases browse by herbivores

Biogeography - Forests of North America

  • Coastal Plain Forests
    • Grasslands, savannas, shrublands, needle forests, broadleaf evergreen, and mesic forests are all found intermixed
    • Sediments - mountain, alluvial (rivers), loess (wind)
    • During the last glacial maximum, these vegetation types were forced southward and persisted until the glaciers retreated and they reclaimed more of their previous range
    • Climate - Humid subtropical - 0C-18C - frost is uncommon - rain is evenly distributed - weather is violent (tropical storms, hurricanes, fires caused by lightning strikes)
    • Soils in this area are ultisols, they weren't scraped away during the last glacial maximum, so they are old and highly weathered
    • Vegetation
      • Northern Pine Barrens - the northern range of the Coastal Plain Forests
        • Here there is a gradient in fire frequency and tree height
        • Pinus rigida, P. echinata are common
        • Pine-oak forest - fire interval 16-26 yrs
          • A. rubrum, N. sylvatica
        • Pine-shrub-oak
        • Dwarf pine plains - 8 yr fire return interval
        • Xeric sand communities
          • Water and nutrient deficits prevail
          • 3-4 year fire return interval
          • Xeric longleaf woodlands
          • Subxeric longleaf pine woodlands - higher moisture
          • Sand pine scrub - dense shrub understory - 20-60 year fire return inverval
        • Mesic pinecommunities
          • Flat woods
          • Savannas
      • Upland hardwood forests
        • Gulf, South Atlantic, Mississippi alluvial valley
          • Well drained, mesic - Q. alba, Carya, L. styraciflua
          • Mesic, fertile - F. grandifolia, Magnolia grandiflora
        • Loess Hills Forest
          • Thick loess - L styraciflua, Tilia, Q. nigra, Q. pagoda, C. cordiformis, C. caroliniana
          • Thin loess - F. grandifolia, N. sylvatica, Q. velutina, Q. alba
        • Sandy uplands - P. taeda, P. echinata, Q. alba, C. tomentosa, Q. phellos
      • Wetlands - 15% of the land in the South
        • Variation has to do with the water (quality, flow velocity, periodicity, duration)
        • River Swamp Forests
          • Bald cypress - Taxodium distichum - butressed
          • Water tupelo - Nyssa aquatica
        • Drier areas
          • Q. laurifolia, A. rubrum, L. styraciflua, U. americana
      • Disturbances
        • Natural - fire, hurricanes, flooding
        • Human - Habitat alteration (draining wetlands)
          • Altered disturbance regime (fire supression)
          • Landscape fragmentation (road building)

Climatic Constraints

  • Climate drives biome and community distribution
    • Low winter temperatures
    • Insufficient summer warmth
    • Higher summer temperatures - especially coupled with low moisture availability
    • Lack of winter chilling factor - cold may signal them to break dormancy
    • In all of these conditions a tree may be able to cope, but not competetively
  • Climate change manipulates the optimal ranges of tree species - optimal environments for species may become sub-optimal
    • Within the geologic past, climate has changed and paleoecologists are not as worried
      • Plants evolve and migrate simultaneously
    • Current climate change is progressing much faster
      • Maybe it has changed this fast before, but thereare other sressors
    • Pollution, increased nitrogen counts
    • Fragmentation
    • Invasive species
      • Competetors
      • Pests and parasites
  • Why do we care what happens in forests - why not just let them do their thing?
    • We depend on these ecosystem serices that forests provide
      • Water and air quality
      • Soils - runoff prevention, building, enriching, substrate we can use but it takes a long time to make
      • Habitat for animals we depend on
      • Quality of life - rereation
  • Changes in temperature will not be uniform
    • An increase in temperature may have different effects in different biomes
    • N. Canada - formerly limited by temperature - will change radically
      • Permafrost may melt, the growing season will increase
      • Imagine a N limited system getting a huge influx - the result is eutrophication
      • This situation is similar
    • Along the Mississippi River floodplain, a slight change in temperature, all other factors equal, will result in less water
      • Oak-Hickory forests may change into shrublands
    • In Michigan, higher temperature - higher evapotranspiration will dry out a landscape
  • Climate change on forests
    • Drought may stress a forest
    • It will experience more forest fire damage
    • This will make the forest more susceptible to pest infestations
    • We will continue to harvest forests
    • Drought intolerant species will regenerate poorly
    • Drought tolerant species will invade
    • The water table will drop
    • Grasslands will replacce the driest forests
    • Seedling survival may decrease
    • Replanting efforts may be less effective
  • Studies documenting the effects of climate change
    • Large scale range studies
      • Long term datasets will be required
      • This has been documented in birds and butterflies which migrate farther north
      • On mountains studies have shown tree-lines moving to higher altitude
    • Shift in species composition
      • Has been measured more in herbaceous communities - they shift faster
      • The idea is that as conditions change, some species become better adapted while others become worse adapted
    • Phenology - timing - leaf drop, flower, leaf out, reproduce, migration
      • Prunus mume - flowering of the cherry tree is important in Japan and S. Korea
        • Meteorological stations record flowering date every year
        • First you need to see if there is an environmental change - is the temperature increasing - yes it is
        • Now see if the flowering day is changing - the trend is decreasing (ie: flowering is occurring earlier)
        • When you plot mean winter temp vs flowering date the trend is clear
          • Warmer winters and early flowering correspond
            • When the winter is 10C or higher, there is effectively no winter - the trend breaks down
      • Other changes induced by global warming
        • Plants
          • Leaf fall is delayed
          • Leaf unfolding is advanced
          • Flowering is advanced
          • Growing season is extended
        • Animals
          • Animal activity is advanced after winter
          • Spring migration is advanced
          • Fall migration is delayed
          • Breeding seasons are extended
        • The point is that this may cause altered synchronization between trophic levels
          • Altering species competetive ability
        • Another example - caterpillars
          • Caterpillars have timed themselves to be most active right after leaf out
            • Plants dont have time to prepare chemical protection
          • A migratory bird times their egg hatching to occur when the caterpillars are most active
          • Plants are very sensitive to temperature - the unfold much earlier in the season
          • Caterpillars respond to temperature, but not as much as the plants - they are delayed - less successful
          • The birds are in the south, they don't know what is going on to the north
          • Their eggs hatch too late to take advantage of the caterpillars
          • Warming results in earlier leaf out, the caterpillars miss it, and the bird eggs hatch when there is little food for them
  • Climate scenarios vs Climate model
    • Scenarios - has to do with CO2 in the atmosphere
      • A - business as usual
      • B - keeping emission at present levels - no increase
    • Models - simulate different situations
      • There are different models - made by different groups in different countries
      • Models vary because they have to make predictions and those predictions vary somewhat between models
    • We want to try to predict how forests will change as climate changes
      • Start with current distribution on forests - Forest Service data
      • For Michigan, it looks like Oak Hickory forests will move north while boreal moves out of the lower peninsula and into the upper and Canada.
      • Many alpine tropical ecosystems will disappear - distributional ranges will increase in elevation, but the species at the tops of mountains can't move out, they may be lost
        • This is also going to take place in the far north, where plants cannot expand their range farther north

Human Impacts
* Habitat loss and fragmentation are having a much larger effect on species than climate change is currently
* The changes we're causing aren't random, we generally ty to inhabit the most fertile places
* Landscape fragmentation - the emergenc of discontinuities in an organisms habitat
* May have natural causes - geologic: rivers, earthquakes, mountain range formation, etc
* When humans cause fragmentation, it occurs much faster and usually results in species extinctions
* Causes habitat destruction and degradation
* Isolates species, can prevent movement between patches, increases risk from stochastic events
* Species Area Curve - S=cA^z - Species=constant*Area^z
* With more area - you find more species
* How much area do we need - what is the minimum patch size - we must maintain to keep the planets biodiversity
* Landscape connectivity is a way to tackle the problem of fragmentation
* Look at the number of patches, their distanc from each other, and whether they are linked or not
* Landscape features
* Corridors - links that provide habitat
* Stepping stones - not a continuous corridor
* Soft matrices - the dominant landcover type that is usually the most modified
* Add trees to your farm
* Maintaining patches
* Large and structurally complex patches
* A matrix that is structurally similar to the native vegetation
* Buffers around sensitive areas
* Corridors or stepping stones between patches
* Landscape heterogeneity and capture environmentalgradients
* Major alterations
* Removal of vegetation for pasture
* Increases wind and water erosion
* Dryland salinity
* Irrigation salinity and waterlogging
* Soil compaction
* Vegetation loss
* Invasion of exotics
* Mass movement of soil
* Chemical contamination of water
* Soil acidification
* Forestry
* Reductions in stand structure and complexity
* Modifies available habitat for many species
* Burning deadfall or woody debris - increases particulates in air and water
* Road building causes fragmentation
* Fuelwood harvesting
* Affects stand structure
* Leads to habitat degradation
Ecological Restoration

  • What is ecological restoration the process of assissting the recovery of an ecosystem that has been degraded,damaged or destroyed
  • We used to think that we could just set areas aside and they would be fine - but that's not necessarily true
  • People can be negative agents for change - but we could play a critical role in restoration
  • Our traditional attitudes were that nature is wilderness - nature is a commodity - deny management by native peoples
  • First experiments were to restore prairies - became a laboratoryin prairie burns
  • Questions in restoration - what to restore to?
    • pre-European settlement models
    • Look for reference sites - reference conditions? - if you can find them
      • Walpole island First Nation - prairie and oak savanna - host 80% of Ontario's endangered species
    • Emphasis on the processes rather than setting a final endpoint for restoration - historical trajectory
    • Other emphases
      • Disturbance is important - fire, windstorm, heavy snow
      • People are part of the system
      • Landscape ecology / Conservation biology - landscape patches, coridors
  • Characteristics about restoration
    • Negotiation / testing process - somewhat experimental
    • Based on ecological knowledge - perhaps testing that knowledge
    • Incorporates the perspectives of the stakeholders
    • Restoration is a process more than a product
    • Restoration is about restoring people's relationship with nature
  • How do you do restoration?
    • Ecological assessment of site and larger landscape context
    • Identification of referece site or conditions
    • Establish goals and objectives
    • Explicit plants for treatments and alternatives
    • Process for evaluation and adjusting
    • Long-term management
  • Case Study - Nichols Arboretum
    • School Girl's Glen
      • Stabilize the ravine with carpet and native plants
      • Stabilize another slope with a boulder dam that would hold back sediment in which plants can grow
    • Dow field
      • Not mowed anymore - reintroduced burning
      • Suppresses non-natives - encouraged native prairie species
      • Some native plants only began showing up after many years of burning
      • Big-bluestem flourishes when burning takes place during the dormant season
      • Leaf-hoppers only do well when prairies are allowed a few years to recover
      • Meadow-voles avoided recently burned areas until mid-July
      • It is important to have a patchy type of burn
      • Using a three year burn cycle - there tends to be less supression of non-natives

Pests and Invasions

  • Invasive Species - a non-native species whose introduction does, or is likely to cause economic or environmental harm
  • Invasive species:
      • Reduce global biodiversity
      • Homogenize communities
      • Alter ecosystem processes (succession), landscapes, and biogeochemical cycles
  • Invasive potential
    • Enemy release hypothesis
      • Escape from predators and pathogens - increased competetive ability
      • Propagule study
        • Example: Ailanthus altissima and Japanese honeysuckles were planted in Ann Arbor
        • Example: Kudzu - planted in the south the prevent soil erosion, given to farmers for free
      • Allelochemical production (root exudates) - novel to the non-native range
        • Example: Ailanthus altissima
        • Example: Garlic mustard - disrupts some mycorrhizal interactions
      • Windows of opportunity
        • Japanese barberry - introduced to be used as a hedge, but farmers were abandoning fields and suddenly the introduced species was given the opportunity to colonize much more space
    • Pathways of introduction
      • Natural spreading - by wind and water
      • Accidental introduction - hitch hiking species - Emerald Ash Borer - associated with trade
        • Faster trade and a higher volume of trade - increases introductions
        • Example: Loading cargo planes at night attracts insects - load them during the day instead
      • Deliberate introduction
        • Example: Rabbits in Australia, kudzu, many ornamentals and flowers, autumn olive
  • Invasion phases
    • Lag phase
    • Rapid growth phase
    • Peak population - this is where we see ecological and economic harm
  • Summary
    • Invasive processes
      • Species pathway
      • Transport and release
      • Population establishment
      • Spread
      • Impact
    • Management
      • Prevention
      • Early detection, rapid response
      • Control and slow spread
      • Adaptation - Example - Eucalyptus in California, the native herbs have adapted to tolerate them
    • Recommendations
      • Reduce species in pathways
      • Institute riskscreening
      • Monitor for early invasions
      • Establish control programs
      • Slow the spread of pathogens
      • Invasive species management
  • Forest Pests - only 20% are invasive
    • In the west forests are stressed by warming climates so they are more susceptible to native species
      • In addition, winter temperatures are increasing and pests can colonize farther north
    • Beech bark diseases
      • Introduced in 1890 from Europe into Nova Scotia
      • Spread by beach scale insects - teperature limit of -37C
      • Some vigorous trees are resistent - we can manage with ladybird beetles, and insecticides
    • Hemlock woody adelgid - more damaging in the south where temperatures are higher

Emerald Ash Borer (EAB) - Agrilus planipennis

  • Likely introduced in Detroit through packing pallets in 2005
  • The beetle larvae girdle a tree by boring through (and eating) the cambium of Fraxinus spp.
  • The beetles tend to target large trees
  • Ash trees are commonly found in riparian areas with high water tables
    • As ash trees die the water table rises
    • In addition the riparian zone may be destabilized as the roots decompose ???
  • DNR is trying to understand and prevent the spread of EAB
    • Purple boxes with manuka oil are used to attract the insects in Ash stands
    • Nicotine insectisides are used as a natural deterrent
      • Injected into trees or soil
      • Costly - only used for important trees
      • A fungal parasite is being studied to use as a biological control agent
      • A parasitoid wasp is also being studied
      • Disinfecting firewood - and preventing people from moving firewood
      • SLAM - SLow Ash Mortality
        • Reduce EAB population growth
        • Detet and prevent satellite populations from expanding
        • Develop and maintain regular communication with landowners

Hemlock Woody Adelgid (HWA) - Adelges tsugae

  • Aphidlike insect from Asia - introduced early in the 20th centuryin New England
  • Eggs » Crawler (mobile) » Nympha » Adult
  • Crawlers attach to the base of a needle and feed on the phloem
    • Trees are defoliated
      • Mortality is high in the southern Appalacians
      • Mortality is low near the northern range - where conditions are worse for HWA
    • Hemlocks are important old growth species - if they go, so do many other species that depend on them
  • They coat themselves in a waxy substance that protects them from attacks by other insects
    • Pesticides are ineffective
    • We don't know of any biological control species
  • The insect is limited in northern range by minimum temperature in march - global warming will expand its range
  • HWA is moved around on hiker's clothes and boots
  • DNR surveys bird feeders looking for the crawlers - this helps them monitor the populations

Insect Pests and Climate

  • Stressed trees have a harder time coping with pests
  • Stressed pests are less virulent
  • Climate change is altering the the amiable and stressful ranges of both pests and hosts
    • Insects tend to do better en masse in warmer areas

Michigan's Landscape

  • 1 - Southern slope of an end morrain
    • Resources - High light > higher temp > less moisture, average nutrients (flushing, but morrains are relatively nutrient rich)
    • Special Features - no
    • Relevant Species Interactions - ?
    • Dispersal - no
    • Dominant Tree Species - Oaks, hickories (waterloo)
      • Maybe too dry for hemlock, beech, and maples
      • Maybe too wet for pines
    • Subcanopy tree species - Prunus, Cornus
    • Shrubs
  • 2 - North face of a hill
    • Resources - Low light > cooler temperature > more moisture, average nutrients (flushing, but morrains are relatively nutrient rich)
    • Special Features - no
    • Species Interactions - high level of pathogens (not relavant)
    • Dispersal - no
    • Dominatn Tree Species - Beech, sugar maple, basswood, hemlock, bottom - RAVE - bottom
  • 3 - Kettle Lake
    • Resources - high moisture, open > high light, high nutrients
    • Special Features - slow decomposition, low oxygen > shallow roots
    • Dominant Species - red maple, thuja, leatherwood, ilex
  • 4 - Outwash
    • Resources - sandy, dry, low nutrients
    • Special Features - fire
    • Relevent Species Interactions - mycorrhizae and rhizobium
    • Dispersal and Reproduction - Wind dispersal, serotinous cones, thick bark, fast growing, resprouters
    • DominantSpecies - Quercus alba, velutina, ellipsoidalis, populus, macrocarpa, Prunus virginiana, jack pine, fire savanna species, elms
  • 5 - Ground Morrain - flat
    • Resources - Moderate water, nutrients, light depends on development of the forest
    • Special Features - no
    • Relevant Species Interactions - no
    • Dispersal - seed bank
    • Dominant Tree Species - Juglans, Carya, Hickories, many others
  • 6 - Riparian Terrace
    • Resources - lots of water, nutrients, light
    • Special Features - flooding, dynamic (erosion)
    • Species Interactions - no
    • Dispersal - water dispersal
    • Dominant Species - Acer negundo, vines, Asimina, Salix, bladdernut, red maple, liriodendron, populus, betula, Quercus palustris, bicolor, silver maple, rubus, platanus
  • 7 - Lake Sediment
    • Resources - clay soil, variable water table, high nutrients (high cation exchange capacity)
    • Special Features - microtopography
    • Relevant Species Interactions - no
    • Dispersal - no
    • Dominant Tree Species - Nyssa, buttonbush, Q. bicolor, Robinia, spiraea alba, ilex, corylus, Q. palustrus, some betulas
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