Evidence of deforestation

Abrams and Rue (1994) analysed the link between deforestation and Maya collapse in Copan, Honduras (Figure 1). They state that the population of Copan grew by 5,000 people from 550 AD to 700 AD and then by a further 20,000 by 850 AD, when it was at its peak. However, during the period from 850 AD until 1000 AD the population declined dramatically by 50% and then by a further 50% during the following 150 years. Copan became completely uninhabited by 1200 AD and was not occupied again until the 19^th Century. 

Figure 1: Map of Central America showing location of Copan, Honduras (Source: Adapted from Image)

Evidence for deforestation was gained from palynological data obtained from a core extracted from the Agua-da de Petapilla, a small bog located just north of Copan. Figure 2 shows the expected decrease in arboreal species during the Late and Terminal Classic periods and a gradual reforestation period associated with an increasingly reduced population. It can be seen that the significant reduction of arboreal species, particularly that of the dominant pine, Pinus oocarpa Schiede, correspond temporally to the Late Classic period.

Figure 2: Pollen profile (Source: Abrams and Rue 1994)

  

It was estimated that at least 23 km² of the upland pine forest may have been completely cleared by the end of the Late Classic period. An assessment of human needs for arboreal resources suggests that deforestation was the result of extensive clearing from the foothill zone for agricultural and habitational purposes and from the upland forest zone for domestic purposes of cooking and heating. Abrams and Rue (1994) believed the data suggested that three was not a sudden collapse in population but a more gradual decline

Having correlated deforestation with the time of Maya collapse, Abrams and Rue (1994) then studied its effect on the soils. It was found that surface runoff, sediment and nutrient loss greatly increased following the burning of pine from upland slopes. In fact, vegetation cover was discovered to be the primary factor in affecting these rather than slope angle. It was concluded that these factors led to the reduced productivity of the agricultural infrastructure and thus the decrease in population at Copan.

Aside

Interestingly, Abrams and Rue (1994) alluded to some lessons that may be learnt from the Mayan system that may prove very beneficial today. They state that the process of deforestation is best considered as a consequence of the broader process of urban growth, evidenced by increasing population size and density at Copan and other Late Classic centres. In this way, the relatively dispersed catchment areas of pre-urban settlements formed a larger single urban catchment area, leading to increased exploitation and denudation concentrated around centres. Many urban areas in less developed countries are evolving in this way and, it is warned, that if unchecked such processes could result in the same way as with the Maya.