conifer plantation management module 2

Conifer Plantation Management

Module 2 1

ManagingYour

Plantation

Module #2


Module 2 2

Managing Your Plantation

Species and their roles Plantation dynamics Inventory Density Management Crop Planning

Topics


Module 2 3

Species & Their Roles

Typical plantationsPure blocks Mixtures

red pine white pine white spruce Norway spruce Jack pine white cedar

red pine and white pine Jack pine and white pine other mixtures with hardwoods


Module 2 4

Excellent variety of forest products

Nurse crop Usually single

rotation Thin to maintain

vigour

Species & Their RolesRed Pine


Module 2 5

Excellent array of forest products

Nurse crop Component of next

stand Susceptible to insects

and diseases

Species & Their RolesWhite Pine


Module 2 6

Site protection and rehabilitation

Nurse crop Subject to windthrow Limited product

potential Not native to Southern

Ontario

Species & Their RolesJack Pine


Module 2 7

Good markets for pulp and sawlogsWill be part of the continuing forestRe-establish cover on wetter sitesLimbs can be tenacious

White SpruceSpecies & Their Roles

http://faculty.washington.edu/edford/ESC455/respace1.jpg


Module 2 8

Good option for limestone sites

Ability to capture site

Planted mainly for wildlife habitat Wide variety of products — cedar leaf oil,

posts, grape stakes, sawlogs, pickets

White CedarSpecies & Their Roles


Module 2 9

Plantation Dynamics

Important Concepts… All forests change over time

– growth, death, reproduction

Land can support so much biomass

Plantations tend to have trees that are similar in:

Species Size (diameter/height) Age


Module 2 10

Plantation Dynamics Trees grow!

What is the ‘right’ number of trees?

Do you have too many or too few?

Stocking Too many –

Overstocked Too few - Understocked Just right – Optimal

Stocking


Module 2 11

Trees will die if too crowded (OVERSTOCKED) Branches will be too big if too few trees

(UNDERSTOCKED) Need to maintain optimum growing space

for trees as they mature Thin for to maintain growth and vigour

(IDEAL STOCKING) Properly managed forests produce the

best forest products

Plantation Dynamics


Module 2 12

Plantation Dynamics

Initial spacing ~2,500 trees/hectare

Final crop 200-300 trees/hectare

Trees removed either by: Mother Nature You


Module 2 13

Forest Inventory

You need to know how your forest is doing

An inventory is a snapshot of your plantation at that time

Use the inventory information to determine what to do

Harvesting without an inventory is a BIG mistake


Module 2 14

100

Forest Inventory

All information is summarized on a per hectare basis

A series of plots are established in the plantation

Information on the trees within the plot is gathered

Must do more than 1 plot (the more the better!)

The results from each plot are averaged together

How do I inventory my plantation?

10010

0

1 Hectare


Module 2 15

Forest Inventory

A circular plot of 5.64 meters radius is 1/100th of a hectare

Two types of data collected Plot Data

The number of trees The diameter of each tree

Stand data The age of the plantation The top or dominant

height

How do I ‘measure’ my plantation?


Module 2 16

Forest Inventory

Mr. & Mrs. Smith own 10 ha of property that was planted 30 years ago with 25000 red pine seedlings

An example….

they put in 20 plots they counted and

measured the diameter of each tree in the plots

they measured the heights of 10 of the largest trees in the stand


Module 2 17

Forest Inventory

2-3

An example….

Inventory Summary

Age = 30 years

Top Height = 15 meters

Average Diameter = 15.3 cm

Average # trees/Ha = 2400

Species: 100% Red Pine


Module 2 18

Density Management

relationship between tree numbers, height, diameter and volume

a planning tool to adjust tree numbers

Optimum growth on each stem

Increase financial return when to thin how many trees to remove

The DMD (Density Management Diagram)


Module 2 19

Density Management

Made up of several partsWe will look at each one

Need to use it systematically A lot of science has gone into it

What you need to know about the DMD

?


Module 2 20

Keep in mind the inventory from the Smith Plantation

Parts of the DMD… Number of Trees

Inventory Summary Age = 30 yearsTop Height = 15 metersAverage Diameter = 15.3 cmAverage # trees/Ha = 2400Species: 100% Red Pine

X-axis = trees per ha Logarithmic scale


Module 2 21

Parts of the DMD… Number of Trees

There were 2400 trees per hectare

Originally planted at 2500 some trees lost through

mortality


Module 2 22

Parts of the DMD… Average Diameter

Average diameter represented by upward sloped lines

2 cm intervals

The dashed line represents the average diameter for the Smith Plantation


Module 2 23

Parts of the DMD… Density/Diameter Relationship

Intersection point is important Can use this point to estimate

the average tree volume, management options etc.


Module 2 24

Parts of the DMD… Average Tree Volume

Y-axis represents average tree volume

In this example the average tree volume is .12 cubic meters

What would the volume be per hectare?

Total stand volume?


Module 2 25

Parts of the DMD… Stand Growth Lines

A Crown closure lineB Thin-to LineC Grow-to LineD Max. Density Line


Module 2 26

Parts of the DMD… Stocking Zones

Three separate ‘zones’ Indicates relative

stocking The Smith plantation is

overstocked


Module 2 27

What happens to a stand over time

Age is about 10 years Crowns begin to touch Site is fully occupied by

trees Lots of room for growth Period of rapid growth

begins


Module 2 28


Grows into the zone of optimum stocking

‘best’ growth rate


Module 2 29


Trees start to out grow the site

Growth slows dramatically

Some trees are lost to stress


Module 2 30


If left as is, this trend would continue

The ‘Mother Nature’ management approach


Module 2 31

Open space Large crowns Large thick branches Space between trees

under-utilized When is “wide” too

wide

Understocked Stands


Module 2 32

Small crowns Susceptible to

windthrow, insects, diseases

Reduced product potential

Limited management options

Overstocked Stands


Module 2 33

Larger diameters on fewer trees

Increased product potential Healthy woodlot

vigorous fights off insects and

diseases minimizes ice storm

damage

Optimally Stocked Stands


Module 2 34

Need to reduce the number of trees/ha

Shooting for optimal stocking; i.e. between the Thin-to and Grow-to lines

Ideal number is on the Thin-to line

Maximizes the number of years between thinning

Developing a Management Prescription

How Many Trees Need to Come Out??????


Module 2 35

Can’t draw a straight line across to the Thin-to line

Thinning tends to increase average diameter

Thinning does not increase dominant or top height



Module 2 36

Height lines are curved Many stands won’t

have the height listed in the DMD

It is the curve (trend) that is important


Parts of the DMD… Height Curves


Module 2 37

Follow the height line back to the Thin-to line

Project a line down to the X-axis (density)

In this example the number of trees to be removed is about 1200 per hectare



Module 2 38

If the stand is well overstocked, never cut more than 1/3 at any one time

If the stand is near to, or at the Grow-to line, you can harvest more than 1/3


Rule of 1/3

Should Mr. Smith thin 1200 stems/ha?

overstocked


Module 2 39

In this case the stand is well overstocked so Mr. Smith should only harvest 1/3 of the total # of stems

1/3=800 stems/ha


Should Mr. Smith thin 1200 stems/ha?

The prescription…. Harvest 800 stems/ha

overstocked


Module 2 40

We know… Trees are planted in rows We want to harvest 33% (1/3) of the stand

So… Cutting every 4th row would be 25% That is about 600 trees/ha Still need another 200 trees/ha 200 trees is about 11% of the remaining trees

(200/(2400-600)) This equals about 1 out of every 9


What does 800 trees/ha mean??


Module 2 41

Mark for harvest every 4th row and approximately 1 out of every 6 trees in the remaining rows.

Select smaller, damaged, poorer quality trees from within the rows


The Final Prescription…


Module 2 42

Volume per tree was .12 m3

Harvest prescription = 800 stems/ha Estimated harvest volume/ha …

800 * .12 = 96 cubic meters

There are 10 ha Estimated Total Harvest Volume…

10 * 96 = 960 m3


How much volume….


Module 2 43

Harvested logs are worth something Prices and markets vary considerably Most first thinnings are paid for by tonnage not

number of stems


How much is it worth….

Currently… 1 tonne is worth ~$5 which is about $4.25 per m3

Mr. Smith’s harvested trees are worth

$4,590


Module 2 44

Options limited by plantation design Take the worst and leave the best Adjust to circumstances Always refer to and update plan Remove enough to allow stand to

maintain vigour First thinning must allow for future access

— row thinning

Some thoughts


Module 2 45

Thinning increases average tree volume of remaining stems

Some thoughts


Module 2 46

First thinning ~25-30 years 15-20 cm

average diameter (Dbh)

up to 1/3 of the original stand

every fourth row plus 1 tree out of 5- 6 on other rows

First Thinning Summary

AB


Module 2 47

Mechanical row harvesting

1 row in 4 removed Trees/rows marked

First Thinning Summary


Module 2 48

We know what we have Now

What will happen later?

Crop Planning

THEFUTURE


Module 2 49

Second INVENTORY Age ~ 40 Trees/ha= 1600 Average Diameter = 18cm

Crop PlanningSecond Thinning

Plot point on DMD to see where the stand ‘sits’

Is it time to harvest?


Module 2 50

Crop PlanningSecond Thinning

selection system remove poorer

quality stems release crop trees pulpwood, sawlogs may promote

hardwood regeneration

maintain health and vigour

CD


Module 2 51

Choose the smaller trees

Identify future crop trees

Estimated volume per tree = .250

Harvest 600 trees per hectare

Estimated Harvest=.250*600*10=1500m3

Crop PlanningSecond Thinning – What Trees?


Module 2 52

Crop Planning

Access roads, trails and landings established

All or most poor quality trees removed

High quality trees left with room to grow

Easy felling for remaining trees

After the 2nd thinning


Module 2 53

Use the DMD to tell you how many to harvest

Every 8 – 10 years Selectively thin - choose

poorest quality trees first Can identify final crop

trees

HarvestsA = 2400 to 1600B = 1600 to 1000C = 1000 to 600D = 600 to 375

Crop PlanningSubsequent Thinnings

AB

C


Module 2 54

D was 4th thinning - 600 to 375 trees per hectare

375 trees per hectare is the final harvest

Need to wait for: Stand hits grow-to line A good market presents itself

Protect new forest during final harvest(s)

Advanced saplings and polewood present

Use skid trails already established

Crop PlanningThe Final Harvest

D

$


Module 2 55

DMD is a tool that can be used to predict when you need to harvest

Keep in mind… Tree height is even across the stand Height growth is related to the quality of the site Height is related to age of the tree

Crop PlanningWhen will my plantation need thinning?

Both trees are the same age.

Which one came from the better site?

Which one has the larger diameter?


Module 2 56

Need to look at Site Index (SI) curves

SI is a measure of the height to age relationship

Better sites have taller trees

Crop PlanningThe Height Factor


Module 2 57

Crop PlanningWhat does SI mean?


Module 2 58

Crop PlanningWhat SI is the Smith Plantation?

From the inventory…Height is 15Age is 30

22


Module 2 59

Crop PlanningWhen will the Smith Plantation be 20 m tall?

22

SI=22, Height=20 Interpret from SI that age would be ~ 43 The Smith plantation will be 20 meters tall in

about 13 years


Module 2 60

Crop PlanningHow many years to the next thinning?

Starting at 2400 stems/ha Harvesting to 1600 Not at thin-to line (yet)

Trees grow in diameter and height

Harvesting does not change stand height


Module 2 61


The remaining trees grow in height and diameter

Next harvest should occur when the stand hits the Grow-to Line

Use the DMD to estimate the height at the time of harvest

In this case it would be about 16m


Module 2 62


The next harvest will occur at stand height=16

The SI will tell us how long this will be

In this case, the next harvest should be in about 2 or 3 years!


Module 2 63

Crop PlanningAnother example…

Height= 12.4m SI=16

What’s wrong with this picture?Now

When?


Module 2 64

Crop PlanningAnother example (continued)…

Height= 12.8m Plots on DMD at

14.4 m

The height growth is what is important

Here it is about 3.5 m

3.5


Module 2 65

Crop PlanningAnother example (continued)…

53 – 35 = 18 years It would take…

If the SI were 20 it would take 14 years If the SI were 28 it would take 7.25 years


Module 2 66

Trees that are selected to grow until the final harvest location growth rate species straightness

Crop PlanningCrop Tree Selection


Module 2 67

Don’t need to prune every tree

Must prune Red & White Pine crop trees Increases value Reduces disease

Crop PlanningCrop Tree Pruning


Module 2 68

Crop Planning


Module 2 69

Thinned vs. unthinned A volume case study

Activity Age Pulpwood yield Cu.metres/ha

Sawlog yield Cu. metres/ha

Thinning #1 36 55.6 —

Thinning #2

Thinning #3

49

64

61.0

177.0

11

330

Activity Pulpwood yield Cu. metres/ha.

Sawlog yield Cu.metres/ha

Harvest at age 60 209 90

Unthinned Plantation

Thinned Plantation

totals 293.60 341

Crop Planning


Module 2 70

Thinned vs. Unthinned A volume case study

Crop Planning

Plantation Yield

0

100

200

300

400

500

600

36 49 60 64

Age

Volu

me

Sawlog

Pulp

UnManaged

UnManaged Total Yield/Ha = 300 m3 Managed Total Yield/Ha = 634 m3


Module 2 71

Crop Planning

conifer plantation management module 2

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