Biodiversity and Forest Ecology
Abstract:
We want to understand the effect that abiotic and biotic elements have on the diversity of the flora and
fauna in our temperate, coastal area. We will be going outdoors to investigate what is found in a forest.
There will be quadrats in various locations, each with a smaller sampling plot within. Each quadrat will
enclose a tree along with plants and signs of animals such as tracks, scat, holes and more. We will record
abiotic data including air temperature, site location, and soil temperature, pH, and type/condition. We
will collect and record biotic data, including plant and animal species and abundance. We will draw or
sketch a picture of the unit site that will help us see what is there now and continue our research year to
year to see what changes occur and how we can help sustain the biodiversity that is needed to ensure a
thriving healthy community.
Goals:
 To understand that forest habitats consist of a diversity of animals and plants in
relationship with the non-living elements in the environment.
 To understand that biodiversity is important for sustaining and enabling the life there to
continue.
 To understand the contribution that abiotic elements, such as climate, soil, water, space,
and shelter have on the populations and communities that live in a forest.
 To observe and record the changes to your plot over the course of a month during Spring.
Procedure:
DAY 1
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Select and lay out your circular 5m radius area (“Site Description Plot”). Be sure to
choose an area:
o With at least some trees
o With diverse flora and fauna
Within the 5m area, select and lay out your square 1m2 area (“Sampling Plot”). Be sure to
choose an area that is representative of the larger 5m plot. “Representative” means that it
reflects the larger area in terms of plant species and cover. Avoid bare areas or unusually
dense areas.
Draw, label, and explain your Geolocation (create a map) well enough to replot your
Sampling Plot EXACTLY for future observations. As we are looking at changes over
time for the same area, it is important that your plot location does not change.
Fill out the Site Description #1 form for the larger 5m Site Description Plot.
o Future samples will include only changes and new info on these forms. You will
be given new forms each visit.
DAY 2
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Fill out the Data Collection #1 form for the smaller 1m2 Sampling Plot. Data collection
will include:
o Soil type
o Soil pH
o AWC
o Flora
 Including identification of trees, shrubs, herbs and, if possible, mosses
 Cover of each individual species. See cover assessment guide. Note that
combined cover for all species can be greater than 100% due to layering.
 Colour of shrub leaves (e.g. pale green, dark green, reddish, etc)
 Shrub growth. Measure new growth only. Select 3 stems and flag for
repeat measurements. Measure length of any new growth.
o Fauna count with drawings and/or identification (including fauna evidence –
disturbance, tracks, slug trails, webs, trash…)
o Tree (canopy) cover within 5m, circumference, height, and increment bore.
WEEKLY DATA COLLECTIONS
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Repeat DAY 2 twice a month for the semester.
Analysis
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Outline patterns that you noticed over the course of the plot study
Discuss factors in this ecosystem/region that may have lead to these patterns
Describe any abnormalities/unexpected results that occurred and discuss possibilities
as to why
Conclusion
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Give an overall picture of the data, a synopsis.
List some positive and negative take-aways.
GEOLOCATION
Draw and describe the location of your plot below. Be sure to include enough detail and
measurements to exactly (coordinates?) place your plot again.
DATA COLLECTION SHEET within square metre (sampling plot) #1
Canopy Cover:
Soil Type:
Flora
ID:
AWC (L, M, H):
Fauna
Coverage/Growth
Leaf Colour
SITE DESCRIPTION #1
Biome description:
Regional location description:
Canopy Cover (number of trees, spp. of trees, height of trees, time of year):
Ground Cover (dominant spp. and %’s):
General Growth:
Soil Change:
DATA COLLECTION SHEET within 5m plot
Canopy Cover:
Tree ID:
Count
Larger Shrubs and Herbacious
ID:
Circumferences
Fauna
Count
Coverage
What is Soil Texture - And Why Does it Matter?
Soil texture is about the mineral portion of your soil. When you hear that it takes a thousand years to
make an inch of soil, what you are hearing about is how long it takes to create the mineral portion of
your soil.
Just the Minerals - Sand Silt and Clay
Soil Particle Sizes
Soil texture is a measurement of the mineral parts of your soil, those ground up bits of rock pulverized
over the millennia. It is calculated by measuring the proportions of sand, silt and clay particles in your
soil.
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Sand... the gritty bits. Each grain is about the size of the head of a pin.
Silt... smooth and soft like flour. Each particle is about the diameter of a strand of human hair.
Clay... sticky when wet. Each bit is microscopic, about the size of a bacteria.
The sand, silt and clay make up the mineral part of your soil. Ideally a soil has about 45% minerals, 25%
water, 25% air and 5% organic matter.
Your soil texture has an enormous effect on water and on nutrients.
Soil Texture or Soil Biology
Soil experts at the cutting edge say that 90% or more of the function of the soil comes from biology.
Happily organic matter is an effective way to help deal with problems with texture. Organic matter
holds nutrients very well. In the water department it can help improve drainage in clay and hold water in
sand. It's an all purpose fix.
With compost, mulches and cover crops even the toughest soil textures can come alive.
Soil Texture and Nutrients
This is a gross simplification of one of the ways plants get the nutrients they need. Below is a chart with
17 of the nutrients we know plants need to be healthy.
The non mineral elements, Carbon, Hydrogen and Oxygen, plants get from the air and water. About 95%
of the weight of the plant is made up from these three elements. Only about 5% by weight comes from
the minerals in the soil. These are still essential to plant growth and health however.
Plants take up their nutrients from the soil in ionic form
for the most part. If you look closely at the above chart
you'll see little + and - signs. The ones with + signs are
cations. The ones with - signs are anions. Most of the
essential ions are cations or ions with a positive charge.
The sand and silt portions of your soil texture are
essentially ground up rock differentiated by their size.
These do not have an electric charge.
Clay is different. Clay is a colloidal substance. It is always
formed through a chemical weathering process. Each
microscopic clay particle carries negative charges along
its edges. This is where soil fertility dynamics live.
They act as places to hold cations - the positively charged
ions that plants need for their nutrition.
How Can I Increase My Soil's Ability to Hold Nutrients?
Happily soil organic matter, especially humus, has a very high ability to hold nutrients. Its CEC runs 150
to 300. So even though your organic matter is a very small part of the soil it has a significant impact on
soil’s ability to hold nutrients.
How Soil Texture Works With Soil Water
Your soil texture has a huge effect on how water moves and is stored or not stored in the soil. There are
three types of water dynamic at work here.
Gravitational Water
When it rains or you water your garden water moves into the soil filling all the pore spaces. Over the
next few hours or days, depending in part on the soil texture, the excess water will drain away.
Sandy soils have big pores so the water will drain away fast. Clay soils have much smaller pores so
gravity drainage may take several days. Plants can use this water while it is present. In sandy soils this
happens fast so plants living in sandy soils tend to have roots that can take up the water fast… because it
drains away fast too.
In the figure to the right, Left is the Gravitational Water Draining
Through the Soil, Middle is the Capillary Water Held in the Soil
Pores, Right is the HygroscopicWater Surrounding Each Soil
Particle
Capillary Water
Once the excess gravitational water drains away there is still lots
of water left in the soil. The water is held in place partly by the
tendency of the water molecules to stick to each other and to be
attached to the soil particles.
The amount of water in the soil immediately after drainage is done is called the field capacity. Almost all
this water is available for plants.
Hygroscopic Water
This is a very thin layer of water surrounding each of the soil particles. This type of water is held so
tightly by the soil that it is not available to plants.
A tablespoon full of sand would cover a table while the same volume of clay would cover a football field.
Given that this film of water covers the surface of each soil particle you’ll end up with way more
hygroscopic water in clay soil than in sands or silts.
Plant Available Water and Soil Texture
This diagram shows just how much of the water in the soil is
available to plants growing in soils of different textures.
As you can see here while most water might be held in a clay
soil, the most plant available water would be in a silt loam
soil.
How Can I Improve Water Issues in my Soil?
The way we can work with soil texture is by adding compost and by maintaining some cover either living
or as a mulch on the soil surface.
Compost in heavy clay soils improves drainage and in sandy soils improves water holding capacity.
For each 1% increase in organic matter you can store about 20,000 gallons of water per acre. The water
held by organic matter would be plant available.