Lab 4 Sampling Plant Communitiez

Question 0

The IMPORTANCE VALUE

Answer 0

Used to estimate the ecological importance of a species in a community

Question 1

For trees what are the 2 factors used to generate the importance value

Answer 1

1. The density of individuals ( number of individuals per unit area)
2. The size of individuals per unit area- DOMINANCE

Question 2

Why are these values considered relative values

Answer 2

Since ecologists want to know how these factors vary relative to the community as a whole

Question 3

2 ways ecologists characterize and compare communities

Answer 3

Determining which species are the most important members in a community
. With respect to overall species diversity

Question 4

The simplest species diversity index is

Answer 4

SPECIES RICHNESS

The total number of species present in the community

Question 6

PLOT SAMPLING

Answer 6

Aka: QUADRAT SAMPLING

. This involves setting out rectangular plots in the forest and taking data on all individuals within the plot

Question 7

Density of individuals is determined by

Answer 7

counting the number of individuals within the plot and expressing this as the number of individuals per unit area ( e.g. trees per 100m^2)

Question 8

The size of a tree is determined by

Answer 8

measuring the diameter or cross sectional area of the tree trunk ( since trunk size correlates with overall tree size )

Question 9

BASAL AREA

Answer 9

this used to indicate relative tree size
. Basal area is the cross sectional area of a tree trunk and reflects the overall size of the tree

.It is calculated from measurements of trunk diameter at breast height ( d.b.h.)
. species becomes more important as its density and average size ( as expressed in basal area) increases

Question 10

Why is soil study important

Answer 10

because they play an important role in determining the distribution and abundance of plants beause they affect

1. seed germination
2. competitive interactions
3. overall plant survival

Question 11

What 3 things are tested in soil

Answer 11

. ph
. soil moisture
. soil texture
( in respect to clay silt and sand)

Question 12

Acids

Answer 12

are compounds that release hydrogen ions (H+) when in a solution

Question 13

Bases

Answer 13

are compounds that accept hydrogen ions ( also contain hydroxide ions )

Question 14

pH

Answer 14

.is a measure of the negative logarithm of the hydrogen ion concentration ( ph = -log [H+}
. Is measured on a scale of 0-14

Question 15

The pH scale

Answer 15

Neutral = 7.0
Acidic = 7.0 

Based on a logarithm scale. a change from one unit to the nest represent a a 10 fold scale

Question 16

Why do ecologist measure soil ph

Answer 16

.beacuse the availability of many nutrients are only available to a plant if they are in a solution
. and the tendency of a nutrient to go into a solution depends on its pH
. A soil of pH 6-7 is the ideal

Question 17

What are the 3 types of soil moisture

Answer 17

. Hydric ( wet) ( marshes, bogs and swamps) ( HYDROPHYTES)
. Mesic ( intermediate) ( MESOPHYTES)
. Xeric ( dry) ( rocks, grasslands, deserts) ( XEROPHYTES)

Question 18

HYDROPHYTES

Answer 18

Beacuse saturated soils of little oxygen for plant roots . Hydrophytes of special features that allow them to adapt, but preclude them from living in other habitats