Term
| Highlights of Stand Initiation |
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Definition
-Micro-site conditions: abiotic factors, micro-topography, size of a seedling.
-Species characteristics: relative competitiveness, sets stage for biodiversity
-"Clumping" from favorable micro-sites.
-Also: Duration, timing, stochasity, competition of non-woody herbaceous |
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Term
| Highlights of Stem Exclusion |
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Definition
-SI to SE
-Clumping transitions to increased random distribution
-Density dependent mortality
- 1-on-1 competition |
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Term
| Highlights of Understory reinitiation |
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Definition
-Least studied/focused; usually foresters cut down after stem exclusion
-gap dynamics or small scale disturbances
-1st cohort no longer dominating
-density independent mortality due to autogenic(age) & allogenic(minor disturbances-edge effect, windthrows), not from competition |
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Term
| Umbrel Light & Penumbral Light |
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Definition
-Directly shaded under tree, darkest shade, especially under dense canopy.
-Penumbral: parts of day may be full shade, but can still have some PAR wavelengths coming through, where you'll find shade-tolerants(420mm of light) |
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Term
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Definition
-Lots of CWD and snags= lots of habitat variability
-High density of fungi/microbes, decomposers, 50% of live cells in snags due to decomposers
-snags good for birds
-CWD makes good micro-sites
-CWD LASTS A LONG TIME so good for habitats
-point for old growth: increasing spatial variability for habitat. |
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Term
| Units of measurements: DBH, Altimeter, allometry, below-ground measurement. |
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Definition
-fine roots(<2cm), buds, Branches- hard to measure
-easiest to measure is diameter; USE Diameter at breast height(DBH=1.3m)
-Altimeter: measures height, lasers measure distance to tree & angle to tip.
-Allometry: measures rest of things using diameter & height, uses basic measures of shape to calculate volume or mass of tree
-Allometry: based on characteristic crown structure and growth pattern, cut down tree and weigh it to calculate volume, used more in simple systems (not rainforests); basic approach to measuring above ground; foliar/branches as well.
-Measure below ground measure through root-shoot ratios & site characteristics(moisture availability), highly inaccurate.
-avg site has 50% above/50% below- water stressed would have 80% below ground(grasses). |
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Term
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Definition
| Yield=standing volume or mass of wood per acre/area; dependent on entire history of stand: site condition, interspecific competition, regeneration, history of spacing/thinning; cumulative growth. |
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Term
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Definition
| -change in yield over time, annual whereas yield is total, year after year. |
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Term
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Definition
| -biomass increment + mortality; all of carbon that went into the tree; whether still there or died from self-pruning or limbs died off, CWD, Snags. TOTAL CARBON INTAKE- also known as Gross primary productivity (GPP) |
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Term
| define: Net primary productivity(NPP) |
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Definition
| -Just biomass increment (subtract mortality & respiration) just living wood. |
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Term
| Narrow spacing vs. Wide spacing tree growth; change w/ age & site condition. |
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Definition
-narrow spacing = slower crown closure
-wider spacing = same amt of growth but over longer period of time |
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Term
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Definition
A densiometer is what you use to measure canopy openness. It is usually a
spherical mirror with a grid on it that let's you count what percent is
open sky |
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Term
| Forestry/Sivliculture basic strategies |
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Definition
-start w/ a lot of trees
-plant close, straight up(less branching)
-removing trees and trying to increase growth to forecast ending volume.
-Carbon Market caculation based on change in management manipulation- not Business as usual. |
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Term
| -trees per area(spacing) & stand age |
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Definition
Reverse J-curve.
-when forests start to regenerate, initially a bunch of trees then high density-dependent mortality early in stand development.
-as stand gets older, initial cohort takes control of growing space.
-Natural forest expansion over time. |
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Term
| Volume/area & age graph on tree growth. |
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Definition
-entire cubic feet of wood in tree
-volume per area over age depends on how quickly thinnig is happening; balanced multi-cohort stand with partial cutting looks like waves, whereas single-cohort harvests looks like large dunes. |
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Term
| How to increase max volume after crown closure |
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Definition
-when you hit max efficiency, its time to harvest, no new growth increments.
-Controversy:does spacing matter in long run? |
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Term
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Definition
initial spacing does not matter; for a given site, you'll get a guiding line of yield- start w/ narrow, crown closure early which is your max grow growth/yield.
-with multi-species/multi-cohort, you have crown differentiation, you will have ideal steady state. |
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Term
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Definition
-initial spacing does matter, opposite of constant yield;
-Initial spacing alters time of max growth
-Looks like: narrow will grow up early and then hit max growth and asetote off, whereas wider spacing is slower increase in yield/crown closure, but higher ending volume. Shown mostly in Doug Fur trees.
-If getting carbon credit in short term, then go with constant yield, where as long term forestry yield looking for more/better 2by4's , sit back and wait w/ wider spacing. |
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Term
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Definition
-Avg diameter of all trees based on allometric calculation of diameter and # of trees. Finds thinning neccessary for optimum yield of your stand.
-based on # of trees/area and diamter(DBH)
-10,100,1000(log scale) trees/acre & avg tree diameter: 3 in by 1000(example), STAND DENSITY INDEX COMBINES TWO to get avg diameter across all trees using allometry to translate into yield. |
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Term
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Definition
-continuing to thin infinitely
-two objectives: increase overall yield & get good trees for good lumber.
-mimics minor disturbances(tree fall gaps)
-taking out trees that will fall/die anyways.
-small forest owners do this to maintain family forest as functioning habitat.
-Disadvantages: removes CWD/snags(habitat diversity of old growth), nutrients, getting trees out of forest causes huge amt of damage(soil compaction), high grading(continous removal of biggest trees with based form- loss most successful regenerative trees=long-term genetic degradation)
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Term
| multi-species/multi-cohort |
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Definition
| -suppression, reduced increase, wavering line, higher harvest/carbon sequestration if filling in growing space taken over by suppressed trees. |
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Term
| Top 3 global change factors effecting forests |
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Definition
1) Land use/cover change: converting forest to grassland, plantation cover, TYPE OF VEGETATION or other cover CITY/SUBURBS- land use: go from natural grassland->grazed grassland
2)Climate change- Change of carbon cycle, CO2(%50 of climate change)N2O/NOX, methane, change in: temp/rainfall/intensity & frequency
3) Changes in global nitrogen cycle- least known factors of global change, DOUBLED biologically available nitrogen- fertilizers, fossil fuel combustion, GLOBAL FERTILIZATION EXPERIMENT. Fertilizer washes out, transported in water; mineral form gets off-gased into N2O(acid rain), byproduct of fossil fuel combustion.; Mostly localized/regional in 100mi radius. |
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Term
Basic facts on HOW ISOTOPES ARE USED TO MEASURE VITOSEKS 3 Factors of change.
-what are the heavy/light isotopes of C,N,O,H
-What do processes favor?
-Which is more common? |
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Definition
-heavy and light isotopes; mass shift
-lighter always more abundant: C12,N14,H1,016
-heavy isotope is rare: C13/(14-radioactive), N15, H2, O17/18
-Physical and Biological processing is bias towards lighter isotopes. |
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Term
| Nitrogen Isotope identification for; N-fixing trees |
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Definition
Want to figure out why N-fixing trees are invasive:
-N-fixation does not discriminate(no bias-lighter), should have same mineral composition as atmosphere. Leaves should look like atmosphere.
-Native trees use mineral nitrogen; organic nitrogen from decomposed leaf litter, bacteria break down and release gas(N20), losing lighter nitrogen, leaving more heavy, leaves will show bias of soil.
-Measuring leaf tissue of invasives can show reliance on N-fixation for role in invasion; can also use soil nitrogen if available.
-fertilizer(ultra-light); if there is a lot of heavy nitrogen left from fertilizing it means there's a lot of offgasing and you are overfertilizing.
-Atmospheric smog/acid rain(light because it's a gas) |
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Term
| Oxygen Isotope indentification for what? how? |
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Definition
-Water source, determines if climate is increasing droughts in site.
-O16 light/017&18 heavy
-Source pools: ground water(light), streamwater(heavy), rain (unbias-based on evap/condense; distance from ocean/topography)
-Mixed pool: Tree rings |
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Term
| Carbon isotopes used for what identification? How? |
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Definition
-Used to determine land use cover/change of trees and grass.
-C12 is light/c13/14 heavy
-Source pool: Tree(C3)/grasses(C4)
-Mixed pool: soil |
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Term
| How do we know climate change is happening; annual release of fossil fuel; How are natural processsing helping us fight global warming? how has it changed in 100,000s years compared to recent? How much has temp raised? And how much has the temp raised in last 100 years? |
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Definition
-CO2 increases from fossil fuel: 5.6pg/yr;6-7 gigatons
-Plants photosynthesize more & warming oceans absorb more
-Carbon has always been flucuating, but in last century there's been exponential increase in carbon
-temp raised 0.75 celcius in last 100 years. |
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Term
| CA assembly bill 32: what are some C sequestration strategies? |
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Definition
-forest rotation increase from 30 to 80-100 years
-rangeland afforestation, converting ranges to forest cover.
-Must show "additionality"- make forests larger, shift clearcut to selective cuts, reduce range area, conservation tillage, cover cropping.
-Cap & trade, carbon credit
-CA produces 1.4% of global GHG, 15th in the world. |
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Term
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Definition
| -Intergovernmental panel on climate change: scientific intergovernmental body[1][2] tasked with reviewing and assessing the most recent scientific, technical and socio-economic information produced worldwide relevant to the understanding of climate change. |
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Term
| What are the 3 forms of symbiosis |
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Definition
-Mutualism: both species benefit, ex. ant & acacia(plant provides shelter/ants protect); Plant-microbes/funig interaction
-Comensalist: One sided-benefit, other not effected; epiphtyes.
-Parasitism: One-side benefit, one-side lost; mistletoe. |
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Term
| Obligate vs. facultative symbiosis |
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Definition
-Obligate: Can't be removed from relationship, co-evolved so long together.
=Facultative: Can live in symbiosis but can also break off from relationship when not beneficial. |
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Term
Reciprocal adaptations: plant defense and herbivores
-large mammals |
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Definition
Plant defense and herbivores: (most plants will do both of these) TOLERANCE- higher photosynthetic allocation on rapid growth, AVOIDANCE- Physical(thorns,leaves,spines)/chemical(toxins,reduced nutrients, change pH) defense mechanisms; Herbivores can build up resistance, change outbreak timing to early in growing season, harder at adapting to physical adaptations; ARMS RACE Between plants and animals.
-Co-evolve and drive/impact natural history
-Large mammals: ungulates(large grazers) eat a lot of grasses, so in response they are highly adapted to sprouting. |
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Term
| co-evolution: plant natural history/reproduction and animals |
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Definition
-pollination: insect(especially important in low wind/tropical rainforests)
-seed dispersal:dispseral in poop, good microsite; bacteria, water, nutrients |
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Term
| Alpha diversity: Shannon and SImpson |
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Definition
-Shannon: increases w/ greater number andevenness. Most widely used.
-Simpson: also takes into account species # and evenness. Homogenous population will have # of 0, hetero=1 |
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Term
| Beta Diversity: Sorensen's & Whittaker's |
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Definition
Sorensens: Total # of species in community 1 and 2, and the number of common species between sites.
Whittakers: Takes into account total # of species in both communities and avg # found within community. |
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