Kefri acting CEO Dr Jane Njuguna said the tree needs to be planted, managed, and utilised in a way that optimises the envisaged gains and supports economic development with minimal undesirable environmental effects.
“We have guidance on where this tree species should be grown. Eucalyptus should not be grown near water bodies. It should not even be planted in riparian areas,” Njuguna said.
Eucalyptus tree species are said to be thirsty, draw a lot of water, and grow fast, often drying streams.
Njuguna said the Kenya Forest Service Kefri in consultation with forest stakeholders, developed a guide to on-farm Eucalyptus growing in Kenya, following concerns raised over claims that the tree draws a lot of water.
The tree species has a number of benefits.
The wide range of products, such as firewood, charcoal, building materials, fencing posts, transmission poles, pulpwood, timber, and plywood obtained from Eucalyptus, have made the genus very versatile.
“As Kefri, we are scientists, so we give sides, the negative side and the positive side of the tree species, and also guide on either side,” she said.
The CEO said site matching must also be adhered to while planting the species.
Site matching ensures the right tree species has been planted in the correct area.
The government already has a rule that eucalyptus should not be planted within 50 metres of rivers or water sources.
The species can be planted in areas that have been degraded through soil erosion and loss of soil fertility, as shelter belts and wind breaks on large-scale farms, and in saline areas, among others.
The colonial government introduced Eucalyptus to the country in 1902 to provide energy for the locomotives.
Since then, more than 100 species have been planted in the country.
There are a number of notable Eucalyptus species distributed in different climatic conditions all over Kenya.
They include E grandis, E saligna, E globulus, E regnans, E paniculata, E maculata, E camaldulensis, E citriodora, E tereticornis, E urophylla, and E hybrids.
Grandis and E saligna species are recommended for Western Kenya, including all high-potential areas of Rift Valley, Migori, Kuria, Kisii, Nyeri, and Kiambu.
Globulus, which was the first species to be introduced in the country, is recommended for Molo environs, Nyandarua, and railway stations countrywide, while E regnans is recommended to be grown in South Kinangop, Keiyo, Molo, Timboroa, Londiani, and other high-altitude areas.
Paniculata is recommended in Nairobi, Kiambu, Nakuru, Nanyuki, Trans Nzoia, and the hilltops of Makueni and Machakos, while E maculata is recommended for Nyeri, Nairobi, Nakuru, Nanyuki, Keiyo, Uasin Gishu, and Trans Nzoia.
Camaldulensis is recommended for dry areas of Nyanza, Coast, Busia, and the semi-arid lowlands countrywide, while E citriodora is recommended for lower areas of Nyanza, Nairobi, Nakuru, Nyeri, and Nanyuki.
Urophylla has been tried at the Coast, Busia, Meru, and lower Nyanza, while E tereticornis is recommended for planting in Kakuzi (Makuyu) and the Coast region, while Eucalyptus hybrids are recommended for the Coast, lower Nyanza, mid-Eastern, Rift Valley, and Western.
Statistics show hectares under the species run to thousands in the country.
The guide says a lot of concern has been expressed about the effect of Eucalyptus planting on hydrological patterns, with various claims that their presence on the landscape is causing the drying up of water sources, rivers, and springs.
The guide says the claim that the tree species is thirsty has not been conclusively supported by scientific evidence.
"However, studies have established that Eucalypts exhibit high efficiency in water use for biomass accumulation. For example, it has been established that eucalyptus requires less water to produce one kg of biomass than most crops,” part of the guide says.
The guide says the effects of eucalyptus on the water budget will depend on the species in question, climate, soil conditions, nature of rock substratum, vegetative cover, slope, tree growth stage, and tree density and amount of rainfall.
The controversy surrounding the tree species landed in the National Assembly last year after Central Imenti MP Moses Kirima sought to totally ban the planting of the tree in the country and have the existing plantations uprooted.
Under the motion, it would be an offence to plant the tree, and those found disobeying the law if the motion is adopted, would have to pay fines or get imprisoned.
The legislator further wants the national government, through the Ministry of Environment, to put in place punitive measures against people who defy orders.
Kirima says the species contributes heavily to water loss, hence the need to ban it.
"The eucalyptus tree species are majorly cited as high water depleting agents through high consumption, transpiration, and evaporation, thus causing the drying up of streams and rivers and the depletion of groundwater water sources," the motion by the legislator reads.
"The high depletion of water by the said trees has caused adverse negative effects on soil fertility and land degradation and is a serious threat to biodiversity."
Planting of trees, Kirima said, has been on the rise due to its fast growth, good economic returns, and diverse commercial uses.
