In 1985 a biologist counted 750 pine trees in a 250 hectare forest. Using similar counting techniques, the biologist counted 1,250 pine trees in 1990 and 1,500 pines in 1995.

What was the average change of the size of the population from 1985 to 1995?

What was the density of pine trees each year that they were counted?

What was the average change of density from 1985 to 1995?

Answers

Answer 1

Answer:

Suppose that we have a given function f(x)

The average rate of change of the function between two values x₁ and x₂ is given by:

[tex]r = \frac{f(x_2) - f(x_1)}{x_2 - x_1}[/tex]

a) We want to find the average (rate) of change on the size of population from 1985 to 1995.

We have that:

f(1985) = 750

f(1995) = 1500

Then we have:

[tex]r = \frac{1500 - 750}{1995 - 1985} = 750/10 = 75[/tex]

This means that the population of trees increases, in average, at a rate of 75 trees per year.

b) What is the density of trees each year that they were counted?

This will be equal to the quotient between the number of trees and the area.

1985: number of trees = 750 pines

         area = 250 ha

Then the density is:

D(1985) = (750 pines)/(250 ha) = 3 pines/ha

So 1985, there were 3 pines per hectare.

1990: number of trees = 1250 pines

         area = 250 ha

Then the density is:

D(1990) = (1250 pines)/(250 ha) = 5 pines/ha

1995: number of trees = 1500 pines

         area = 250 ha

The density is:

D(1995) = (1500 pines)/(250 ha) = 6 pines/ha

3) now we want to get the average change between 1985 and 1995 in the density, this will be:

[tex]r = \frac{D(1995) - D(1885)}{1995 - 1985} = \frac{6 pines/ha - 3pines/ha}{10} = 0.3 pines/ha[/tex]

So, on average, each year the number of pines per hectare increases by 0.3


Related Questions

I want to know full answer about ecoregion vs. ecosystem.

Answers

Answer:

An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species. The biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. In theory, biodiversity or conservation ecoregions are relatively large areas of land or water where the probability of encountering different species and communities at any given point remains relatively constant, within an acceptable range of variation (largely undefined at this point).

A map of the Amazon rainforest ecoregions. The yellow line encloses the ecoregions per the World Wide Fund for Nature.

A map of North America's bioregions

Three caveats are appropriate for all bio-geographic mapping approaches. Firstly, no single bio-geographic framework is optimal for all taxa. Ecoregions reflect the best compromise for as many taxa as possible. Secondly, ecoregion boundaries rarely form abrupt edges; rather, ecotones and mosaic habitats bound them. Thirdly, most ecoregions contain habitats that differ from their assigned biome. Biogeographic provinces may originate due to various barriers, including physical (plate tectonics, topographic highs), climatic (latitudinal variation, seasonal range) and ocean chemical related (salinity, oxygen levels).

WOmbats are what type of mammals?

Answers

Answer:

Los wombats son marsupiales que solo se encuentran en Australia, pero estos curiosos y simpáticos animales de piernas cortas y rechonchas rara vez son tenidos en cuenta como otros animales nativos como los koalas y los canguros, que parecen ser más mediáticos.

Explanation:

Looking in the rain forest pictures, how would you begin to classify the pants in the scene?

Answers

Answer:

I'm kinda confused can you help me understand it better please

More than two thirds of the world's plant species are found in the tropical rainforests: plants that provide shelter and food for rainforest animals as well as taking part in the gas exchanges which provide much of the world's oxygen supply.

Rainforest plants live in a warm humid environment that allows an enormous variation rare in more temperate climates: some like the orchids have beautiful flowers adapted to attract the profusion of forest insects.

Competition at ground level for light and food has lead to evolution of plants which live on the branches of other plants, or even strangle large trees to fight for survival.

The aerial plants often gather nourishment from the air itself using so-called 'air roots';. The humidity of the rainforest encourages such adaptations which would be impossible in most temperate forests with their much drier conditions.

Jeremiah is an 10-year-old male who is short in stature. His parents have become concerned as Jeremiah is now wetting the bed, drinking a lot of water, and often appears tired/fatigued. The doctor orders several blood tests after Jeremiah's urine test was positive for glucose and ketones.1. What disease(s) should be ruled out in this patient?2. List the tests that are used to diagnose diabetes.3. List the symptoms of diabetes.

Answers

Answer: 2) Tests used to diagnoses diabetes: Oral Glucose Tolerance Test, Fasting Glucose Test, Hemaglobin A1c, Random Blood Suger Test.

3) unexplained weight loss, frequent unination, lethargic, excessive thirst, nausea , and vomititng, increased hunger even though is still eating, blurry vision, bed-wetting in childern who did not do it previously, dry mouth,

Explanation:

What does a botanist study

Answers

Answer:

Botany is the scientific study of plants—how plants function, what they look like, how they are related to each other, where they grow, how people make use of plants, and how plants evolved.

I HOPE THIS WILL HELP YOU

HAVE A GREAT DAY :)

Guinea pigs can produce different coat colors, white, brown, and mixed white/brown (agouti). The allele B is codominant with allele W (white coat). Cross an agouti-colored Guinea pig with a brown Guinea pig. What are the odds of the offspring?

Answers

Answer:

Brown

Explanation:because the agouti itself is a mixture that remains of a pale brown color and the melanin content in the animals is in the darker colors so it is more likely that the brown color is predominant to the agouti due to the content of melanin that it

The descendants of a cross between an agouti heterozygous (AB) colored Guinea pig and a brown (BB) colored Guinea pig are half heterozygous agouti, half homozygous brown. The correct option is A.

What exactly is codominance?

Codominance is a genetic effect that happens whenever the alleles are expressed in heterozygotes.

In this particular instance, allele B co-dominates with allele W, resulting in heterozygous (WB) colored Guinea pigs like one of the parents.

Thus, the correct option is A.

For more details regarding co-dominance, visit:

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The missing options of the question are:

A. 1/2 heterozygous brown, 1/2 homozygous agouti.B. 1/2 homozygous white, 1/2 heterozygous brown.C. 1/4 homozygous brown.D. 1/2 heterozygous agouti, 1/4 white.

What type of factors would have the
greatest influence on a densely
populated area?
A. drought
B. density-dependent factors
C. density-independent factors

Answers

Answer:

c

Explanation:

because in populated areas people are independent

The gas form of water is ____________.

Answers

The gas form of water is water vapor.

Answer:

Water vapor

Explanation:

Hope this is helpful.

Which of the following describes a parasite
1 a bear that kills and eats fish?
2 a worm that lives inside a bear.
3 a dish that is killed and eaten.
4 a bear that has worms in its gut

Answers

Answer:

2

Explanation:

A parasite is an organism that feeds on the intestine of living organiy

The correct answer would be a worm that lives inside a bear! A parasite is something that lives inside a host and is receiving its food from the host — this being the bear! Safe learning :)

b. Bobcats are another predator of snowshoe hare. If a population of bobcats immigrates to the
area, how is this likely to affect the habitat's carrying capacities for hare and lynx?

Answers

Answer:

Decrease population and carrying capacity.

Explanation:

If a population of bobcats immigrates to the  area, the population of hare and lynx decreases that also affect the habitat's carrying capacities for hare and lynx because bobcats feed on both hare and lynx. Bobcats are very aggressive in nature, and has an aggressive hunting style. With these characteristics, the bobcats can hunt both hare and lynx which leads to decrease in population and carrying capacity.

Mountain ranges are created at boundaries between tectonic plates a. b. transform transflux divergent convergent C. d. 5​

Answers

Convergent would produce mountains because they approach eachother

The essence of meiosis is that a. specialized cell division reduces the chromosome number by half b. gametes are formed that are diploid c. specialized cell division doubles the chromosome number d. gametes are formed that are haploid e. a and d are correct

Answers

Answer:

e. a and d are correct

Explanation:

Meiosis produces 4 daughter cells that are haploid. Haploid means they have half of the chromosomes of the parent cell.

The essence of meiosis is that specialized cell division reduces the chromosome number by half and gametes are formed that are haploid.

Therefore option e is the right answer.

What is meiosis?

A single cell splits twice during the meiotic process, resulting in four cells with half the original genetic material. These cells are our sex cells—eggs in females and sperm in males—and they are produced by a specific form of germ cell division in sexually reproducing species. Two rounds of division are necessary, and the end product is four cells with just one copy of each chromosome. The goal is to produce gametes, or sperm and eggs, that contain half of the parent cells' genetic makeup. Meiosis is characterized by DNA replication, two rounds of cell division, and the production of four daughter cells, each of which has half as many chromosomes as the parent cell.

To learn more about meiosis, refer

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plz give a correct answer for the question how do canine and molar differ​

Answers

Answer:

Canines are the sharp, pointed teeth that sit next to the incisors and look like fangs. Dentists also call them cuspids or eyeteeth. Canines are the longest of all the teeth, and people use them to tear food

Molars are the flat teeth at the rear of the mouth. Each molar typically has four or five cusps. They are used exclusively for crushing and grinding. Wisdom teeth are also called third molars. They erupt from the age of 18 onwards but are often surgically removed.Their function is similar to that of the premolars, to grind, tear, and crush food. Molars have a large flat biting surface which makes them perfect for this job.

Explanation:

Hope it works!!!!

Canine are used to tear and found in front of mortal
Mortal are used to chew

What percent of immature T cell thymocytes are eliminated and destroyed by thymic selection to prevent autoimmune diseases?

Answers

Answer:

These cells continue to mature and then exit the thymus, armed to inhibit the activation of self-reactive T cells. It has been estimated that the three steps of thymic selection eliminate 98% of thymocytes.

Match each term with the best description.

a. Membrane-bound structure that supports energy production.
b. Semi-permeable, living covering of the cell.
c. Long, whip-like appendage used for locomotion.
d. Membrane-bound structure containing the hereditary material of the cell.
e. Gel-like substance encompassing the contents of the cell
f. Basic structural and functional unit of living orgaisms

1. Cell
2. Cell membrane
3. Cytoplasm
4. Flagellum
5. Mitochondrion
6. Nucleus

Answers

Answer:

a) 5. mitochondrion

b) 2. cell membrane

c) 4. flagellum

d) 6. nucleus

e) 3. cytoplasm

f) 1. cell

an apple and a glass of milk can give you more nutrition as compared to the milk shake
Prepared from apple and milk. Justify it based on the physiology of GIT.

in detail plz

Answers

Answer:

True

Explanation:

because the milk shake is with cold but milk is hot

Methylation _________of the transcriptional unit results in a __________reduction in luciferase expression, whereas methylation ________the unit causes a ________reduction in expression. The effect of methylation of the transcriptional unit may be_________ by methylation outside the unit.
A. enhanced
B. within
c. reduced
d. drastic small outside

Answers

Answer:mình nghĩ là D

Explanation:

Question 1 of 10
Consider the following geometric solids.
A sphere with a ratio of surface area to volume equal to 0.3 m
A right circular cylinder with a ratio of surface area to volume equal to
2.1 m?
What results would you expect if these two models were compared in a
diffusion test?
A. The rate of diffusion would be slower for the right cylinder,
B. The rate of diffusion would be the same for the two models.
0
C. The rate of diffusion would be faster for the right cylinder.
D. The rate of diffusion would be faster for the sphere.

Answers

Answer:

the rate if diffusion will be faster in the right cylinder

Explanation:

The surface area to volume ratio of the cylinder is higher. This means that in the cylinder more reactants are exposed at the surface and the rate at which diffusion takes place increases

During inhalation, the chest cavity _________ in volume, _________ the pressure in the lungs.

Answers

Answer:

1. reduce la presión interna

2. el aire se precipita hacia adentro y llena los pulmones.

Explanation:

Drag the correct tiles to the box. Not all tiles will be used.
Identify the goods or animals that Europeans introduced to the Americas.
turkeys
wheat
corn
horses it is not horses because it said it was wrong

Answers

Answer:

the eupopeans introduced horse to the americans, as the native american living there already had turkeys,corn,and wheat.

What is the reason for having diverse functions for proteins

Answers

Answer:

to make the body strong

In crude oil affect eggs and larvae of fish and increase mortality.
O a.
Hydrocarbon
O b.
PAH
O c.
liquid petroleum

Answers

Answer:

its c liquid petroleum 100% surr

According to cell theory, all new cells...
A. must share DNA with existing cells.
B. must eat.
C. come from other cells.

Answers

Answer:

с

Explanation:

all new cells come from other cells

Help ASAP PLEASE HELP FAST

Answers

Answer:

I THINK ITS A) ACTIVE TRANSPORT REQUIRES ENERGY

I HOPE ITS RIGHT IF NOT THEN SORRY HAVE A GREAT DAY :)

Answer:

Active transport differs from passive transport in that active transport requires energy

HELP ASAP PLEASE HELP FAST

Answers

I DONT HAVE THE ANSWER BUT GOOD LUCK

please helpppppppppp

Identify the variables in this hypothesis.


If Sam increases his exposure to excessive noise by listening to music through his headphones, then his ability to hear will decrease. This is because when sounds are too loud, they can damage sensitive structures in the inner ear and cause hearing loss.


The independent variable is

.


The dependent variable is

.

Answers

Answer:

The independent variable is excessive noice exposure

The dependent variable is hearing

Explanation:

sorry for you having to wait so long have a mildly amazing day like me lol

Answer:

The independent variable is  : Excessive noise exporsure

The dependent variable is : hearing

Explanation:

I gotchu fam :D

DNA is referred to as a_____,
meaning that it has_______
strands that are______together.

Answers

DNA is referred to as a double helix, meaning that is has two strands that are held together.

Answer:

double helix

two

wound

Explanation:

DNA is referred to as double helix, meaning it has two strands that are wound together.

HELP ASAP NEED HELPPPPP

Answers

Answer:

insects is a write answer.

Anyone know this??? Help!!!
Devise an experiment to test the effect of pH on the activity of biological washing powder

Answers

Answer:

I think you are nepali yeah but I don't have your question ❓ answer

Sperm cells are not normally exposed to blood, but if they are, the immune system may produce ____________ against sperm cells' ____________ and render someone sterile.

Answers

Answer:

Sperm cells are not normally exposed to blood, but if they are, the immune system may produce __auto-antibodies__ against sperm cells' __auto-antigens_ and render someone sterile.

Explanation:

Auto-antibodies are antibodies that can destroy cells from the same organism. They are mistakenly directed against organs or tissues of the same organisms, causing auto-immune diseases or affections. The autoantibodies action occurs when the organism fails in recognizing its own cells and faces them as strange elements.

Auto-antigen is the molecule produces by the body that fails in being recognized due to a break up in the tolerance mechanisms, triggering an immune response.

In the exposed example, sperm cells do not usually mix with blood. So when they do, blood cells recognize them as strange bodies and act against them. Sterility might be an effect of this auto-immune response.

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