Forestry- how many tree per acre?

locky76

I've a few general questions about spruce forestry plantations:

• How many trees are planted per acre first day?
• How many will fail?
• How many will need to be thinned?
• How many will be harvested at final clear fell @ ~35 years?

yourpics

1000 per acre for planting

How many will fail? Not that many once its well established.

Thinning - depends on the situation after 20 odd years

Clearfelling - almost everything that is viable. You may have to leave the odd one here and there if you are in a certification scheme

blue5000

I think spacing at planting is one tree every 2m by 2m.
Thinning could be earlier, maybe at yr 17, depends on the ground.
About 120 trees left at the end /acre. These are usually identified after first thinning, so the poorer trees are pulled out bit by bit over the next 15-20 yrs.

temujinhayes

check out this website below for alternatives to clearfell forestry. the forest commission in wales now employs the idea of continuous cover forestry, more economical in the long term
http://prosilvaireland.wordpress.com/

dipper.meath16

Depends on the species for the planting numbers, then you have to consider exposure, likleyhood to windblow, quality of crop and so on for thinnings!!

valtra8150

sowed 5.75 hectars last year there was 18 thousand trees roughly the lads sowing them said that round 25% of them will fail. when there sowed youll start to see some trees around 3/4 the way up cut at an angle because there was a hair or rabbit track running through there. thinning between 12-20 years depends on the ground and weather.

locky76

valtra8150 wrote: »

sowed 5.75 hectars last year there was 18 thousand trees roughly the lads sowing them said that round 25% of them will fail. when there sowed youll start to see some trees around 3/4 the way up cut at an angle because there was a hair or rabbit track running through there. thinning between 12-20 years depends on the ground and weather.

So by that reckoning 4,500 will fail so at thinning you'll have a growing crop of 13,500 trees.
How many of these trees (%) will be thinned at the first thinning at say year 17?

blue5000

locky76 wrote: »

So by that reckoning 4,500 will fail so at thinning you'll have a growing crop of 13,500 trees.
How many of these trees (%) will be thinned at the first thinning at say year 17?

Normally one row in 7 is taken out at first thinning. Not sure about the maths above, 1000 trees/ acre is roughly equal to 2500 trees /ha.

greenfingers89

locky76 wrote: »

I've a few general questions about spruce forestry plantations:

• How many trees are planted per acre first day?
• How many will fail?
• How many will need to be thinned?
• How many will be harvested at final clear fell @ ~35 years?

850 - 1000 trees per acre (the stocking rate is actually 1000 trees per acre but majority of plantations nowadays have 15% of the site allocated for bio-diversity, this is generally made up of open space/access tracks/road or stream setbacks etc.....however some acres will have 1000 and others could have 600..........even with the 15% rule you'll find many sites are closer to a 900/acre average)

you could have 5-15% failure on a lot of sites by thinning age, say 17-22ish years of age

if your thinning 3 times then 30-40% of the total living trees at time of thinning could be removed

sooooooooooo.....

say you start with 900 trees an acre

age 19 you have 800 surviving healthy trees, thin and have 500/acre left

age 24 you thin and have 330/acre left

age 29 you thin and have 200/acre left

age 34 you clear 180 trees/acre (bare in mind a few trees die over the thinning period as well)

before everyone has a go at these figures, they are JUST AN EXAMPLE and im only putting them up seen as OP asked for details....theres massive variations between forests across the country

locky76

Excellent, so by my reckoning:
Thinning 1 @ 19 years- Take out ~270 trees per acre
Thinning 2 @ 24 years- Take out ~150 trees per acre
Thinning 3 @ 29 years- Take out ~110 trees per acre
Clearfell @ 34 years- Take out 180 trees per acre

greenfingers89 wrote: »

850 - 1000 trees per acre (the stocking rate is actually 1000 trees per acre but majority of plantations nowadays have 15% of the site allocated for bio-diversity, this is generally made up of open space/access tracks/road or stream setbacks etc.....however some acres will have 1000 and others could have 600..........even with the 15% rule you'll find many sites are closer to a 900/acre average)

you could have 5-15% failure on a lot of sites by thinning age, say 17-22ish years of age

if your thinning 3 times then 30-40% of the total living trees at time of thinning could be removed

sooooooooooo.....

say you start with 900 trees an acre

age 19 you have 800 surviving healthy trees, thin and have 500/acre left

age 24 you thin and have 330/acre left

age 29 you thin and have 200/acre left

age 34 you clear 180 trees/acre (bare in mind a few trees die over the thinning period as well)

before everyone has a go at these figures, they are JUST AN EXAMPLE and im only putting them up seen as OP asked for details....theres massive variations between forests across the country