Can Nyandarua County plant 1.4 billion trees in ten years?

By MUNGAI KIHANYA

The Sunday Nation

Nairobi,

21 April 2019

This week, it was reported in a local newspaper (not the Nation) that Nyandarua County Government has entered into a partnership with an private company (Anarrosi Capital Partners) in a project aiming to plant 1.4 billion trees over the next ten years. Yes: 1,400,000,000 trees!

Interestingly, this was pointed out to me by a reader going by the name of Greg Waithaka; in English, “Greg of the forests”! He went on to ask: considering that trees are normally spaced about 4m apart, is there enough land in Nyandarua county to plant 1.4bn?

My family has been doing some agroforestry in Nyandarua county over the last two decades. The varieties on our land are planted on a 2m-by-2m pattern.

After about 5 years, the population is “thinned” by cutting every other tree in the pattern thus leaving the 4m-by-4m that Waithaka is referring to. So, on planting day, we plant about 2,500 trees per hectare (hectare, not acre!) which then drops down to about 1,250 after thinning.

With 2,500 trees per hectare, how much land would be required to plant 1,400,000,000? The answer is 560,000ha. This is a very large area; it’s about 1.4 million acres!

Such large areas are better expressed in square kilometres. One sq.km. is equal to 100ha. So, 560,000ha is works down to 5,600 square km. Does Nyandarua county have this much land?

The answer is simply no! The entire county sits on just 3,108sq.km. So, there is absolutely no way it can host 1.4 billion trees.

For comparison, Kenya has about 6 per cent of its 580,000sq.km total area under forest. That is, about 46,600sq.km. In the natural environment, the density is about 250 trees per hectare. Thus, the entire republic has about 870 million trees – less than one billion.

The news report further stated that 140 hectares of land had been set aside for the project. Using the planting geometry on my family’s land (2,500 trees per hectare), the best they can get is 350,000 trees. Nothing close to one million, let alone a billion.

Land area is not the only challenge: there is also the question of who will plant the trees. Is there enough manpower? During planting, we employ about 25 people to plant 5,000 seedlings in one day. This works to about 200 per person per day.

The tree planting season lasts about 4 weeks every year. So how many people are required to plant 1.4 billion trees in 10 years?

This is 140 million trees per year. Woking for 28 days annually means that they must plant 5 million seedlings daily. Since each person plants 200 per day, it means they will need 25,000 workers on each planting day! Perhaps they’re planning to use a planting machine…

In conclusion, I think either the news report or the entire project is not well thought out. People must stop joking with a billion. It’s a very large number!