basis: Given the lack of correlation between dDlw and pollen- inferred mean July temperatures (Fig. 6), the downcore dDlw changes likely represent either a change in the ratio of soil water and precipitation utilized by the vegetation and/ or a change in source and pathway of regional precipita- tion. The dDlw data may indicate a heavy reliance of terrestrial plants on cool-season derived soil moisture from 11,000?8000 cal yr BP when conditions were dry. Growing- season precipitation may have been too low to provide sufficient water to the plants. An alternative and not mutually exclusive interpretation is that growing-season precipitation was not enriched in deuterium from 11,000?8000 cal yr BP because the presence of high pressure over the Laurentide ice sheet prevented the northward advection of humid, sub-tropical airmasses that are important for summer precipitation today. Both interpre- tations are consistent with Shuman and Donnelly?s (2006) interpretation that low lake levels prior to ca 8200 cal yr BP resulted from low summer precipitation rates and a high ratio of winter to summer precipitation.

direction: depends

interpDirection: depends

scope: climate

seasonality: deleteMe

variable: circulationVariable

variableDetail: air@surface

variableDetailOriginal: air

variableGroup: circulation changes caused by ice sheet topography. Precipitation seasonality.

scope: climate

scope: climate

basis: Given the lack of correlation between dDlw and pollen- inferred mean July temperatures (Fig. 6), the downcore dDlw changes likely represent either a change in the ratio of soil water and precipitation utilized by the vegetation and/ or a change in source and pathway of regional precipita- tion. The dDlw data may indicate a heavy reliance of terrestrial plants on cool-season derived soil moisture from 11,000?8000 cal yr BP when conditions were dry. Growing- season precipitation may have been too low to provide sufficient water to the plants. An alternative and not mutually exclusive interpretation is that growing-season precipitation was not enriched in deuterium from 11,000?8000 cal yr BP because the presence of high pressure over the Laurentide ice sheet prevented the northward advection of humid, sub-tropical airmasses that are important for summer precipitation today. Both interpre- tations are consistent with Shuman and Donnelly?s (2006) interpretation that low lake levels prior to ca 8200 cal yr BP resulted from low summer precipitation rates and a high ratio of winter to summer precipitation.

coefficient: NA

direction: positive

fraction: NA

inferredMaterial: soil water

mathematicalRelation: depends on the source area and transport path to the study site

rank: NA

scope: isotope

seasonality: Summer

seasonalityOriginal: summer

variable: precipitationIsotope

variableGroup: P_isotope

variableGroupDirection: positive

basis: Given the lack of correlation between dDlw and pollen- inferred mean July temperatures (Fig. 6), the downcore dDlw changes likely represent either a change in the ratio of soil water and precipitation utilized by the vegetation and/ or a change in source and pathway of regional precipita- tion. The dDlw data may indicate a heavy reliance of terrestrial plants on cool-season derived soil moisture from 11,000?8000 cal yr BP when conditions were dry. Growing- season precipitation may have been too low to provide sufficient water to the plants. An alternative and not mutually exclusive interpretation is that growing-season precipitation was not enriched in deuterium from 11,000?8000 cal yr BP because the presence of high pressure over the Laurentide ice sheet prevented the northward advection of humid, sub-tropical airmasses that are important for summer precipitation today. Both interpre- tations are consistent with Shuman and Donnelly?s (2006) interpretation that low lake levels prior to ca 8200 cal yr BP resulted from low summer precipitation rates and a high ratio of winter to summer precipitation.

coefficient: NA

direction: depends on which season provides source moisture for plants

fraction: NA

mathematicalRelation: depends on which season provides source moisture for plants

rank: NA

scope: isotope

seasonality: deleteMe

variable: seasonality

variableGroup: precipitation seasonality

coefficient: NA

fraction: NA

rank: NA

scope: isotope

basis: match with pollen based January temperature, C16 n-acids are produced by aquatic plants, and ponds in this region are recharged mainly by winter precipitation (Shuman and Donnelly, 2006, Quat Res, 65:44-56)

interpDirection: positive

scope: climate

seasonality: Winter

variable: temperature

variableDetail: air@surface

variableDetailOriginal: air

variableGroup: Temperature

variableGroupDirection: negative

variableGroupOriginal: T

scope: climate

scope: climate

basis: match with pollen based January temperature, C16 n-acids are produced by aquatic plants, and ponds in this region are recharged mainly by winter precipitation

coefficient: NA

direction: negative

fraction: NA

inferredMaterial: lake water

integrationTime: 1 to 2

integrationTimeBasis: lake equilibrium with the mean annual balance of precipitation and evaporation across the watershed

integrationTimeUnits: years

mathematicalRelation: linear

rank: NA

scope: isotope

seasonality: Winter

variable: effectivePrecipitation

variableGroup: EffectiveMoisture

variableGroupDirection: negative

variableGroupOriginal: P_E

coefficient: NA

fraction: NA

rank: NA

scope: isotope

coefficient: NA

fraction: NA

rank: NA

scope: isotope