Q 2: Lab Flashcards
Methods for the purpose of quantitative description(5)
- Cover- i.e, what area does each species cover
- Frequency of occurrence
- Density or number of individuals per unit area
- Biomass or weight per unit area
- basal area
flora
is a list of plant species that occur in a given area where the order of species is related to ease of use.
Ex: Alphabetical order
A flora gives no indication of the importance or abundance of the species present.
Vegetation
is a list of plant species that occur in a given area where the order of species is related to importance or abundance of each species present. The first species in a vegetation list will be the species that has been assessed to be the most abundant or important to the area usually using one of the above measures.
Can be expressed as an absolute measure such as density(# of individuals of a species per unit area) or relative value, usually in percent, such as relative density(density of species X/total density for all species present).
The text has a good discussion of the development of “Importance Values” for species comprising a plant community.
most common technique for measuring plant abundance generally involve…
…setting up a series of straight lines, either parallel or perpendicular(produces a grid system) to one another, in the study area.
This is called “Transects”
The sample reference frames are called:
quadrats
____ can be square, rectangular, and pretty much any other shape other then a circle which is a bounded area.
quadrats
Quadrat size for Moss, Lichen=
0.1- 0.25 m2
Quadrat size for Grasses and forbs
0.25- 2 m2
Quadrat size Shrubs
10- 15 m2
Quadrat Size Trees
100- 150 m2
A point intercept method cannot generate _____ _____.
density data
where do you measure the diameter of Trees basal area?
Areal Cover:
DBH= Diameter breast height 1.5 Metres above the ground.
LAI
Areal Cover:
Leaf Area Index=
.the ratio between total leaf area above the soil surface and the soil surface area.
. Can range from “0” in true desert or “5” in tropical rainforest
.Strongly related to the availability of Photosynthetically Active Radiation(PAR) at any given level within the vertical structure of the plant community.
PAR
Areal Cover:
Photosynthetically Active Radiation=
.How sunlight is soaked up as it goes down vertical stratification.
. See Text(pg.59-2)
Types of Data: 4
- ) Areal Cover
- ) Frequency
- ) Density
- ) Biomass
Areal Cover
Under the criterion of area are included all those methods that take into account- either by estimate, exact measurement, or some related function- the amount of ground covered by individual species and by the whole vegetation.
Areal cover can be defined as the vertical projection of the above-ground parts of each plant onto the ground.
Frequency
related to the number of times a species occurs in a given number of repeatedly placed small sample plots or sample points.
can be distributed randomly, for example, by throwing a metal ring, or systematically by following a regular patterns.
The species are recorded without regard to their quantity or number of individuals.
For comparing different communities, frequency is best expressed as a percentage of the total number of placements, i.e, the frequency percentage of frequency index.
2 types of frequency
- Shoot frequency= obtained by recording as present all foliage overlapping into a quadrat.
- Rooted Frequency= records a species being present only when it is actually rooted in the quadrat.
______ is the most commonly applied quantitative parameter for the analysis of forest undergrowth and herbaceous communities in North American description studies.
Frequency
Rooted frequency
Rooted Frequency= records a species being present only when it is actually rooted in the quadrat.
Shoot Frequency
Shoot frequency= obtained by recording as present all foliage overlapping into a quadrat.
Density
define, characteristics, and difficulties
refers to the number of individuals per unit area usually obtained by a simple count of plants in a series of random quadrats.
.extremely time consuming but extremely accurate
. Suitable for early stages of colonization, ex: stabilization of sand dunes and denuded land undergoing vegetation or recovering after abiotic factors.
Difficulty:
- Recognition of individuals
- Difficult to decipher where one individual begins and one ends
- Rhizomatous and Stoloniferous forms can hardly be counted.
- boundaries may spit shrubs
Biomass
refers to the total dry weight of biological material per unit area and is usually obtained by harvesting plants in a series of random quadrats. These plants are then dried at 60C until a constant dry weight is achieved.
- can be extremely time consuming
- requires extensive record keeping
- Biomass is relatively accurate and generally used in studies where energy within the ecosystem is being examined as biomass represents stored energy.
- Can be used to measure energy flows in ecosystem
Braun-Blanquet scale of cover-abundance(6)
5- covers >75% 4- covers 50-75% 3- covers 25-50% 2- covers 5-25% 1 - covers <5% \+ - present but with very little cover
Point Intercept Method
metal rods drop and whatever they touch is recorded
Line intercept method
using a long thin quadrat along a line
ex: used for varying landscapes that cant sporadically be recorded.
most accurate evaluations in quadrats come from rectangles with approximately a __ to __ ration between sides.
2 to 1
X2(Chi-Square) or Goodness of Fit Test
Small or High
X2= (O-E)2/E
Expresses the square of the difference in units of the expected outcome.
Small chance deviation= high probability of occurrence: p> 0.05
Large non-random deviation= low probability of occurrence: p<0.05
Large non-random deviation= ____ probability of occurrence: p<0.05
low
Small chance deviation= ____ probability of occurrence: p> 0.05
high
Matador Project
an extensive investigation of the mid(mixed) grass prarie on which Northern Wheatgrass and Smith’s Wheatgrass were the dominant species.
Aboveground biomass can be separated into three functions
- Fresh Mulch: dead standing material which gree in current, or late in the previous, growing season and is easily removed.
- Standing crop: live, photosynthetically active material which is clipped at ground level/
Combining 1+2= Shoot Standing Crop
- Litter: the third fraction, covers the surface of the mineral soil as a layer of fine, fibrous organic material which may be several centimetres thick in areas with low fire incidence.
Shoot Standing Crop
Combination of Fresh Mulch and Standing crop
-1 gm dry organic matter=___ KCals=___ kJ
4, 17
this is low because dead organic matter-mulch and litter- is less energetic then live.
Net Primary Production of Shoots= ___ x (standing crop+mulch= shoot standing crop)
1.2
Net Primary Production of Roots= ____ x Shoot NPP
1.33
Underground Biomass= 4 x ______ ___________ _________
Total Aboveground Biomass
GPP and NPP in a True energy flow diagram insolation would be depicted by arrows representing energy flow and arrow _____ would be proportional to the amount of energy carried.
Boxes representing biomass would be drawn with areas in proportion to the amount of ____ each represents.
width
Biomass
PAR
The amount of light energy available for use in photosynthesis by plants of the community is referred to as Photosynthetically Active Radiation.
- Can be measured in many different units such as energy units( kilojoules, joules, calories, etc.) and energy proxies such as grams dry weight biomass or grams of carbon.
- PAR is always an energy measure per unit area per unit time.
PAR can be measured in ____ and/or _____.
Energy units and/or energy proxies
PAR is always an _____ per unit ____ per unit ____.
energy measure, area, time.
GPP
Gross Primary Production:
. The amount of light that is actually captured by photosynthetic pigments in the chloroplasts of the primary producers in a biological community and converted to energy in chemical bonds of glucose.
_____ represents all of the energy that will enter the ecosystem per unit time and is therefore the only energy available to run the entire system.
GPP
Secondary production would be more accurately called _______
secondary conversion
CE?
CE=___/____x _____
Primary Producer Consumption Efficiency:
.Normally calculated for consumer organisms
GPP/PARx100
LCE?
LCE=___/____x____
Light capture Efficiency:
. the amount of light energy stored in the chemical bonds of sugars produced in photosynthesis to the amount of available PAR.
. Total light capture stated in dry biomass per unit area per unit time, is referred to as GPP
LCE= GPP/PARx100
Light capture efficiency can vary widely by ecosystem and dependant on many factors which influence the production of ____ per unit area.
Chlorophyll
The theoretical maximum light capture could be as high as ____% in a perfect system where no PAR escapes photosynthesis. A majority of natural systems capture less then ___% of available light.
12, 1
Some crop plants(____, _____, and _____) and artificial experimental systems have attained light capture rates of up to ___% but light capture efficiencies over ___% are rare in nature.
Sugar cane, corn, and Sugar Beets
6
2