Monocultures | Restoring | Groasis, let's green the world!

A monoculture is a cultivation of one specie or one variety of trees. As it is only one variety these kind of plantations have a very bad influence on ecology. If there is only one variety only a few animals can live from them and lifecycles become impossible. This results many times in plagues as natural enemies to balance too high numbers of a certain (damaging) animal do not exist in such circumstances.

The present development of planting big areas of tens of thousands of hectares with for instance only Eucalyptus or only Acacia’s will turn out to be a bigger disaster for the environment then savanna areas are. In the case of monocultures it is better to have a desert then a green monoculture desert.

Solution

The production of forests can be much higher if we choose for a combination of ecological and economical interesting trees:

Ecologically interesting trees on areas where harvesting is difficult (gaps, ravines, escarpments, really poor soils)
Economical interesting trees in combinations, example
High growing trees in combination with bushes or shrubs producing fruit
The high growing trees in 5 to 10 varieties having symbiosis’s while growing
The high growing trees dividing in fast, slower and very slow growing. Cutting down from the fast until in the end the slowest growing
The slowest growing should be high growing varieties enabling other trees growing below them

Suitable trees for combined growing

The following list is a list of trees suitable to prevent monocultures (Source document ‘Wood Energy’ FAO – Unisylva - editor T.M. PASCA):

Species	Ecosystem	Fw^*	Ti^*	L.f.w.^*	Other uses	Method of propagation	Annual rainfall and climatic/soils conditions
1. Acacia arabica	Windbreaks Shade trees Bush-fallow	XX		X	Pods as fodder	Direct seeding on mounds, strip or line	Alluvial or loamy soil; moist conditions
2. Albizzia falcataria	Shade trees Regular planting in farm forestry	XX	XX	X		Direct seeding or seedlings raised in nursery	Wide range of soils but prefer loamy soil and good rainfall
3. Bamboo (several spp.)	Live fencing Regular plantations in farm forestry Around houses	X	X	XX	Raw material for cottage industries Shoots for food	Rarely from seeds Shoot cuttings	Loamy or clayey soil; moderate to high rainfall
4. Calophyllum inophyllum	Shade trees for amenity (roadsides, around houses, public gardens)		XX		Burning oil	Seedlings to be raised in nursery	Loamy/clayey soil; moderate to very moist conditions
5. Cassia siamea	Shade trees in plantations	XX	X			Direct sowing of seed in lines	Heavy rainfall (poor growth in dry climate)
6. Casuarina equisetifolia	Agri-forestry systems Windbreaks	XX	XX	X	Tannin bark	Seedlings raised in nursery. Planting (1.5- to 2-m spacing) or if too close, early thinning needed	Sandy soil; stand rainfall between 800 and 5 000 mm
7. Combretum quadrangulare	Rice field dikes	XX		X	Medicine	Seedlings raised in nurseries. Direct seeding possible	Loamy soil; slower growth on sandy soil; average rainfall 1500 2 000 mm over 5/6 months
8. Cordia alliodora	Agri-forestry systems Shade trees in coffee plantations		XX	X		Direct seeding (mixed success) Seedlings from nursery - wide spacing (unless early thinning) Natural regeneration good	Moist, well-drained sites; rainfall 1500-2000 mm
9. Glyricidia spp.	Shade trees in plantations or as living stakes	X		X		Direct seeding or stumps	Alluvial or clayey soil; high rainfall or moist conditions
10. Grevillea robusta	Shade trees in tea and coffee plantations Roadside trees		XX			Seedlings from nursery	Sandy soils; 700 to 1 500-mm summer rainfall
11. Leucaena glauca	Windbreaks Shade trees Planting around houses	XX		X	Fodder Green manure Nitrogen fixing	Direct seeding or cuttings	Neutral or alkaline soils, poor growth on acidic houses soil; rainfall 600-1 700 mm
12. Morus indica (M. alba)	Regular plantations for silkworm raising Irrigated roadside or canal planting	X	X		Fruit leaves for silkworm raising	Direct seeding or branch cuttings	Light sandy soil. Moderate to high rainfall (18002 500 mm) or canal planting
13. Pithecellobium saman	Shade/amenity trees	XX	X		Fodder Medicine	Direct seeding or seedlings from nursery	Clayey or loamy soil; high rainfall; moist conditions
14. Prosopis spp.	Plantations for fuelwood Bush-fallow	XX		X	Fodder	Direct seeding (if irrigated) or stump planting	Dry soil, not excessive moisture; grows on rocky and saline soils

^* Firewood, Timber, Light farm wood

Downloads and links

Read all about combined growing in this document from the FAO

Read some articles about the negative effects of monocultures:

Mongabay
China dialogue
Corporate watch