Effects of spatial and temporal climatic variability on terrestrial carbon and water fluxes in the Pacific Northwest, USA

Long-term impact of nitrogen fertilization on carbon and water fluxes in a Douglas-fir stand in the Pacific Northwest

Forest Ecology and Management ◽

10.1016/j.foreco.2019.117645 ◽

2020 ◽

Vol 455 ◽

pp. 117645

Author(s):

Sung-Ching Lee ◽

T. Andrew Black ◽

Rachhpal S. Jassal ◽

Andreas Christen ◽

Gesa Meyer ◽

...

Keyword(s):

Pacific Northwest ◽

Nitrogen Fertilization ◽

Douglas Fir ◽

Water Fluxes ◽

The Pacific ◽

Long Term Impact

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Accurate spatiotemporal predictions of daily stream temperature from statistical models accounting for interactions between climate and landscape

PeerJ ◽

10.7717/peerj.7892 ◽

2019 ◽

Vol 7 ◽

pp. e7892

Author(s):

Jared E. Siegel ◽

Carol J. Volk

Keyword(s):

Pacific Northwest ◽

Prediction Error ◽

Climatic Variability ◽

Stream Temperature ◽

Training Dataset ◽

Spatial And Temporal Patterns ◽

Temperature Modeling ◽

Testing Dataset ◽

Limited Temperature ◽

The Pacific

Spatial and temporal patterns in stream temperature are primary factors determining species composition, diversity and productivity in stream ecosystems. The availability of spatially and temporally continuous estimates of stream temperature would improve the ability of biologists to fully explore the effects of stream temperature on biota. Most statistical stream temperature modeling techniques are limited in their ability to account for the influence of variables changing across spatial and temporal gradients. We identified and described important interactions between climate and spatial variables that approximate mechanistic controls on spatiotemporal patterns in stream temperature. With identified relationships we formed models to generate reach-scale basin-wide spatially and temporally continuous predictions of daily mean stream temperature in four Columbia River tributaries watersheds of the Pacific Northwest, USA. Models were validated with a testing dataset composed of completely distinct sites and measurements from different years. While some patterns in residuals remained, testing dataset predictions of selected models demonstrated high accuracy and precision (averaged RMSE for each watershed ranged from 0.85–1.54 °C) and was only 17% higher on average than training dataset prediction error. Aggregating daily predictions to monthly predictions of mean stream temperature reduced prediction error by an average of 23%. The accuracy of predictions was largely consistent across diverse climate years, demonstrating the ability of the models to capture the influences of interannual climatic variability and extend predictions to timeframes with limited temperature logger data. Results suggest that the inclusion of a range of interactions between spatial and climatic variables can approximate dynamic mechanistic controls on stream temperatures.

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Growth responses of subalpine fir to climatic variability in the Pacific Northwest

Canadian Journal of Forest Research ◽

10.1139/x02-072 ◽

2002 ◽

Vol 32 (9) ◽

pp. 1503-1517 ◽

Cited By ~ 90

Author(s):

David W Peterson ◽

David L Peterson ◽

Gregory J Ettl

Keyword(s):

Soil Moisture ◽

Pacific Northwest ◽

Climatic Variability ◽

Regional Scale ◽

Growth Patterns ◽

Subalpine Forest ◽

Growth Responses ◽

Subalpine Fir ◽

Biogeographic Patterns ◽

The Pacific

We studied regional variation in growth-limiting factors and responses to climatic variability in subalpine forests by analyzing growth patterns for 28 tree-ring growth chronologies from subalpine fir (Abies lasiocarpa (Hook.) Nutt.) stands in the Cascade and Olympic Mountains (Washington and Oregon, U.S.A.). Factor analysis identified four distinct time series of common growth patterns; the dominant growth pattern at any site varied with annual precipitation and temperature (elevation). Throughout much of the region, growth is negatively correlated with winter precipitation and spring snowpack depth, indicating that growth is limited primarily by short growing seasons. On the driest and warmest sites, growth is negatively correlated with previous summer temperature, suggesting that low summer soil moisture limits growth. Growth patterns in two regions were sensitive to climatic variability associated with the Pacific Decadal Oscillation, apparently responding to low-frequency variation in spring snowpack and summer soil moisture (one negatively, one positively). This regional-scale analysis shows that subalpine fir growth in the Cascades and Olympics is limited by different climatic factors in different subregional climates. Climategrowth relationships are similar to those for a co-occurring species, mountain hemlock (Tsuga mertensiana (Bong.) Carrière), suggesting broad biogeographic patterns of response to climatic variability and change by subalpine forest ecosystems in the Pacific Northwest.

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