Trees rock!

If tomorrow someone said they'd invented a self-reproducing tool for atmospheric carbon sequestration, improving water catchments, oxygen production, air filtering, low-carbon building materials, stock shelter, riparian zone protection, erosion management, food, bioenergy, firewood, biodiversity, habitat, paper manufacture, salinity control and recreation they'd be the Bill Gates of the 21st century. We don't have to wait for this invention as trees already exist!

At PragSust we think trees rock. We're developing an agroforestry or farm forestry site on our farm in Sth Gippsland with trees planted for multiple outcomes including many of the above. Ten years ago there wasn't a tree on the place except for some aging, exotic, remnant shelterbelts, a few paddock acacias and a few acacias on steeper slopes where the cows hadn't grazed as intensely. The previous owners planted some trees and we're planting a load more. We're particularly interested in durable timbers, fat logs for slabs and boards, high-value fine timber, roundwood construction using coppiced trees, bee fodder and craftwood for woodturners, garden use and rustic furniture. And we want to continue grazing cattle on the block.

Families owning woods for multiple outcomes is common in some of  the Scandinavian nations, parts of the US and Canada and increasingly in the UK. And farm forestry has become very popular in New Zealand. The length of time required to grow trees to a harvestable size is considerably less in Australia than in many parts of the northern hemisphere. It's quite realistic (in higher rainfall areas) with the correct site, species, outcome and management to start seeing some returns after ten years or so. Although a 20-40 year planning window does open things up a lot.

Some local landowners are also interested in these smaller-scale applications. So we thought we'd put together an initial checklist of some points to consider as part of planning trees on land. While written mainly for landholders this can also be useful in an urban setting. We've planted trees in our garden for bees and food but we do use prunings for other purposes.

Here's the list. Let us know what you think.

i/ What are the site characteristics? Soil, rainfall and temperature across the year, aspect, prevailing winds, slopes and contours.

ii/ What are your objectives? Construction timber? High value timber? Posts? Poles? Food? Onfarm use? Selling off-farm? Firewood? Bioenergy? Wattle structures? Rustic furniture? Bee fodder? Stock shelter and shade? Erosion management? Biodiversity? Habitat?

iii/ Do you want to have a go at practices like coppicing and hedge laying?

iv/ Timeframe. How soon do you want a return? Will you leave the property - and trees - for your children?

v/ How much area do you want to use for trees? Will you plant fence to fence, scattered in a paddock or in small coupes/woodlots?

vi/ Do you want to plant exotics, natives or a mix?

vii/ Do you want a monoculture plantation - some species occur naturally in largely single species stands - or to employ analogue forestry or another mixed species approach?

viii/ Budget. Will you grow some seedlings yourself? It's cheaper to raise trees from seed but it does require time and some skills. Specialist tree nurseries are good at growing trees and will save you time and effort.

ix/ Will you prune yourself? This will involve ladder work. Watching NZ videos of people pruning 12m high is sobering. Pruning for 6m clearwood logs is a common aim.

x/ How will you exclude stock and manage opportunistic browsers such as deer, wallabies and rabbits ?

xi/ Weed and fire fuel load management plan. Once stock are excluded grass and weeds will grow. Once the canopy closes in a densely planted coupe, grass and weeds will be suppressed but that will be some time down the track and may not occur for some weeds, such as blackberries, depending on the type of planting. Blackberries are a tough, successful plant that wants to grow in woodlands and forest edges. As well as rank grass and weeds, once the trees start dropping bark, dead branches, windthrow etc this is potentially a fire risk.

xii/ Will you harvest and thin yourself? This raises issues about safety and training in felling and chainsaw use. Forestry is about the most dangerous rural activity.

xiii/ Will you want to clear-fell - again well-suited to some species natural response to events like fire and cyclone - or use a technique like continuous cover forestry?

xiv/ How much time do you want to spend on forestry per annum?

xv/ What tools will you use? What do you own, what will you buy or hire and what will you get contractors to do? This will depend on whether you want to fell, buck and limb yourself or contract a harvester, use farm equipment to move logs or contractor trucks on farm tracks/roads (which will need to be a suitable standard for trucks to use), mill onsite or at a sawmill (which will require transport to the mill) and so on. Harvest is easier for  the farmer when done by external parties but there is less return to the grower. And for some sites it is prohibitively expensive to get contractor equipment to the coupe so the only option is smaller scale harvesting

Black cockatoos tucking into pine cones in a shelterbelt.

Cows in shelter on a warm summer day. These trees are under ten years old.

Taking a home, building, community, region or nation towards 100% renewable

Mr PragSust has been doing stuff in renewable energy off and on for several decades. There's a lot of interest in Australian communities in moving towards 100% renewable.  PragSust HQ has been carbon free for some time with a biomass heater, PV's and solar hot water. And we've reduced our energy use through various energy efficiency measures. Generally speaking, reducing your energy consumption, using Green Power and installing renewables such as solar hot water and photovoltaics will reduce your emissions. But if you would like to be a bit more systematic, here's a list of steps that might be useful as an initial checklist at a number of scales.

a/ Characterise the energy use at the site in question. As the old saw has it, if you can't measure it you can't manage it.

• How much energy is used.

• When is the energy consumed within a day, in a week and across the year.

• What sort of energy ie thermal or electricity. 

• How much does the energy cost.

b/ Identify energy efficiency measures. As per the perky little aphorism from several decades ago, "Weatherise before you solarise." In Melbourne, companies such as ecoMaster and ecomad specialise in these assessments for residential and commercial buildings. PragSust HQ has had help from both companies with pleasing results. Specialist companies are available to do thorough assessments for industrial and large commercial sites.

c/ Reduce energy use by implementing cost-effective energy efficiency measures. It's a lot easier to find a cheap, cost-effective, practical renewable solution for smaller energy demands. Australian houses, for example, are generally appallingly inefficient with respect to thermal performance ie they leak heat like a sieve. Heat goes out in winter and comes in during summer. There's nothing sexy about roof, wall and underfloor insulation but it is very effective if good quality and properly installed. Weatherproofing to reduce draughts is simple and effective if done properly. In Australia's generally mild climate a well-designed, well-built house achieving HERS 9+ stars or PassivHaus (Australian Passive House Association and Passivhaus Australia have local introductory information on the PassivHaus approach) should need little to no heating and perhaps a small amount of air-conditioning in hot weather. Other measures such as LED's and energy efficient appliances are nice and easy. For larger industrial and commercial energy users, energy efficiency companies say it's not uncommon for them to find 30% reductions in energy consumption at these sites with quick payback periods.

d/ Determine the residual energy demand.

e/ Characterise renewable energy available at the site including any seasonal variations. Renewable energy sources available might be biomass, solar, wind and so on. Each of these sources will have scales and technologies that suit particular demands.

f/ Cost-effectively match the energy sources available with the demands.

• Is storage cost-effective? This might be thermal storage in a tank, battery storage for PV's or hydro storage at larger scale. 

• Can excess generation be sold? For example, feedin tariffs for excess PV generation beyond onsite consumption. Anther example is industrial parks like the one in Gussing, Austria to use process steam from a biomass CHP system.

• Can any demand be deferred or scheduled to match with generation from an intermittent energy source such as solar?

g/ Have the renewable system installed by a reputable company that will do a good job. PragSust has had excellent results from Corospark for various residential-scale renewable systems. Corospark are also doing PV installations at 100kW scale for commercial sites, energy efficient lighting refits for residential and larger sites and voltage optimisation systems for large energy users. Going Solar are designing and installing solar hot water systems for larger sites including school campuses and apartment buildings.

h/ Identify how to meet the demand remaining after deploying cost-effective renewables.This might be from a Green Power scheme.

Rinse and repeat!