We read so often that carbon sequestration can be most effectively accomplished by natural means. The cutting edge high tech solutions are still on trial. They often cannot be tested on a large scale for their global impact or for the unforeseen side effects that may be delitarious. This means they cannot be tested, so they will be applied untested, on a massive scale, like the large scale multiplication of GMO. These technologies are also very expensive, prohibitively so for countries that are not the technically or financially the most prominent nations.
The thing is, we have tested systems which have proved to work and be beneficial over millions of years, in many different climates and microclimates. These systems can be used in any country as their cost is low, and with citizen involvement and volunteering their cost can be zero. These tried and tested symptoms when applied will actually sequester more carbon than the high tech systems.
For natural carbon sequestration, we are talking about increasing soil life, planting multi-tiered plant ecosystems like forests and re-establishing wetlands. Grasslands are also fabulous at sequestration. They will be appropriate for certain climates. The Cape not. Local grasses are adapted to die off in our hot summers leaving hot naked sand. That creates a domino effect of depletion in well trampled urban areas. Exotic grasses like Kikuyu tend to invade, smother other vegetation and decrease diversity.
For my part I will recommend food plants, as they also help with the global food security problem. In a series of blog articles I will address how every human being can help with natural carbon sequestration. We will talk about soil rehabilitation, water conservation and work through the tiers of an artificial forest, or food forest and learn how to build a wetland for next to no cost.
The structure of a forest edge gives
maximum vegetative cover and leaf area for photosynthesis, because it
is made up of several levels or storeys, and there is more leaf at
the lower levels when there is a bit more sun, at the edge. We have a
lot of sun in the Cape. Its an engine for driving carbon
sequestration. In other words, we will learn to build a carbon
sequestering machine.The trees are important as they usually have the
deepest roots and thus store carbon at the deepest depth. They exude
sugars to feed soil mycorrhiza and microbes with which they have
symbiotic relationships, and these sugars contain carbon.
I will start with my climate zone and things I
have tried myself, that are as tough as nails, so that they can be
abandoned to themselves without dying off. This is to suit busy
people who have a bit of a plot but brick it over because they have
no time to garden, and it would suit public areas like vacant lots,
where neglect is likely to come at some stage. I would welcome
contributions from experience from other climate zones. I am going to
keep the lists short, restricted to the things that are guaranteed to
grow. This means there will not be much diversity but in waste lands
with monocultures like the Kikuyu deserts on the road verges and open
lots of Cape Town, adding these plants will represent an improvement.
Into this framework of tough plants,
others can be additions that increase diversity. I would like to start
with native plants but our Afromontaine trees are so difficult to
germinate, and I've spent years trying. Until we have a production
facility pumping out these local trees I compromise with hardy
Mediterranean species for food, that I can grow myself. What we do have
is a rich diversity of
nitrogen fixing leguminous plants in South Africa, and I use these
natives as support
plants, trees, shrubs and herbs, in my food forest, but so far I have
had to buy them. I hope to produce them one day. It is important to use
native nitrogen fixers. Each plant is host to different nitrogen fixing
bacteria, and the exotic bacteria can dominate and irradicate native
bacteria. This spells death for a whole host of nitrogen fixing native
plants in the area of invasion. I will find the article on damage in the
Fynbos, but in the meantime here is one about damage done to prairies.
The disadvantage of the exotic crop trees I've chosen is that they are so hardy they have already been planted everywhere by the city parks department, and you can get harvests just by walking down the road or visiting a park.The advantage is that they will survive in any garden and they represent a way for massive planting up in the city to be possible, despite people being busy, working hard at their jobs, or not having money. This massive tree planting will convert the city's private gardens, public parks, empty lots and highway verges into a carbon sink, consisting of thousands of natural carbon sequestration machines, helping to create a carbon negative city.
The following are the parts of a natural carbon sequestration machine
that I have used myself and have experience of. With time I will add
diversity and richness to this very basic, easy to build structure, with
links to outside sources and other articles on this website.
There should be a list for all the tiers of the forest:
trees (food trees and support trees)
shrubs (perennial food plants and support plants)
There should be help with how to make compost and increasing carbon held in the soil in different ways other than planting.
There should be information on conserving and recycling and cleaning water at extra low cost, including building wetlands