Hierarchical differences within Maya society were increasingly emphasized in a top-down structure that made the society more vulnerable to collapse (Scarborough and Burnside, 2010). Deforestation and erosion in the Maya lowlands results from a combination of climate drying and forest reduction related to increased demands for fuel, construction material, and agricultural land associated with

population expansion selleck products and aggregation. Pulses of deforestation and erosion varied spatially during the Preclassic and Classic Periods. Some studies suggest that this was most acute during the Late Preclassic Period and continued through the Classic Period (e.g., Petén Lakes; Anselmetti et al., 2007). Other records indicate an uptick in deforestation and erosion during the Late Classic (AD 600–900; Cancuen, Beach et al., 2006). At the regional level, it appears that erosion accelerated in many locales between 1000 BC and AD 250 and again between AD 550 and 900 (Beach et al., 2006). In some cases, this was mitigated with terraces selleck screening library constructed during the early and late Classic (Murtha, 2002, Beach et al., 2002, Beach et al., 2008 and Chase et al., 2011) that helped stabilize landscapes. Attempts to manage forests may have stabilized landscapes in some regions (e.g., Copan, McNeil et al., 2010; but see Abrams and Rue, 1988 and Webster

et al., 2000), but climate drying in the Late Classic would have exacerbated deforestation related to population increase and agricultural expansion/intensification (Boserup, 1965). This resulted in lowering the Malthusian ceiling and contributed to increased human suffering and greater variance in well-being amplified during extended drought periods that undermined the influence and authority of kings. This is supported by some evidence for a high degree of nutritional stress

in some populations dating to the Late/Terminal Classic (Copan, Storey et al., 2002) or a high health burden generally in the Classic Period with no clear increase in the Late/Terminal Classic (Pasión region, Wright, medroxyprogesterone 2006). Local attempts to invest in landesque capital (e.g., terraces and raised fields) were too hit-and-miss to mitigate these problems and the transportation networks necessary to subsidize areas most heavily impacted by environmental degradation and drought were not sufficient or were compromised by conflict. The primary response of kings to environmental stress and instability of the Late Classic (AD 600–900) was to go to war. There was an increase in the number of war events recorded on stone monuments between AD 650 and 900 when compared to the previous 300 years (Fig. 4). This is also the case when war-events are normalized relative to other recorded events (e.g., marriages, accessions, etc., Fig. 4, warfare index; Kennett et al., 2012).