From the first millennium B.C. through the 9th-century A.D. Classic Maya collapse, nonurban populations grew exponentially, doubling every 408 years, in the twin-lake (Yaxha-Sacnab) basin that contained the Classic urban center of Yaxha. Pollen data show that forests were essentially cleared by Early Classic time. Sharply accelerated slopewash and colluviation, amplified in the Yaxha subbasin by urban construction, transferred nutrients plus calcareous, silty clay to both lakes. Except for the urban silt, colluvium appearing as lake sediments has a mean total phosphorus concentration close to that of basin soils. From this fact, from abundance and distribution of soil phosphorus, and from continuing post-Maya influxes (80 to 86 milligrams of phosphorus per square meter each year), which have no other apparent source, we conclude that riparian soils are anthrosols and that the mechanism of long-term phosphorus loading in lakes is mass transport of soil. Per capita deliveries of phosphorus match physiological outputs, approximately 0.5 kilogram of phosphorus per capita per year. Smaller apparent deliveries reflect the nonphosphatic composition of urban silt; larger societal outputs, expressing excess phosphorus from deforestation and from food waste and mortuary disposal, are probable but cannot be evaluated from our data. Eutrophication is not demonstrable and was probably impeded, even in less-impacted lakes, by suspended Maya silt. Environmental strain, the product of accelerating agroengineering demand and sequestering of nutrients in colluvium, developed too slowly to act as a servomechanism, damping population growth, at least until Late Classic time.
This article integrates ethnohistorical and archaeological data in examining political continuities or structural equivalencies in the lakes region of central Petén (southern Maya lowlands) between the Late and Terminal Classic periods and the Postclassic and Spanish Contact periods. The equivalencies are of three kinds: “deep structures” (quadripartition), common political expediencies and functions (power-sharing and council houses), and temporal continuities per se (dual rulership). The article concludes that the rupture (“collapse”) between Classic and Postclassic political forms was only partial, and numerous structures and practices of late Petén Itza Maya geopolitical organization can be seen in earlier Classic-period phenomena. These underscore long-term continuities in governance strategies.
The role and training of Queensland guidance officers appears to be set toward the practice end of the scientist-practitioner continuum. Yet data are presented which demonstrate that the expectations placed on many guidance officers are relatively sophisticated and specialised. Particularly in the areas of personal crisis counselling, family support and community-school development, today's guidance officers working in Queensland schools are required to demonstrate considerable specialisation. The profession seems to be facing a choice, attempt to develop into a group of true educational specialists with all the required training, supervision and in-service education or move to become a group of expert general practitioners. Some implications of these two options for the profession are explored.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.