melinda lamb

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Melinda Lamb

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How terrestrial plants, specifically reed canarygrass ( Phalaris aurundinacea ), impact lake functions. Melinda Lamb. Watersheds have significant impacts Lake Conditions. Bed rock leaching Top soil depth (Brown et al. 2008) Vegetation Nutrient uptake/ soil chemistry - PowerPoint PPT Presentation

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Page 1: Melinda Lamb

Melinda Lamb

Page 2: Melinda Lamb

Watersheds have significant impacts Lake Conditions

Bed rock leaching Top soil depth (Brown et al. 2008)Vegetation

Nutrient uptake/ soil chemistryWater consumption/routing

Page 3: Melinda Lamb

Lake Productivity Properties linked to WatershedsChlorophyll –ANutrients - N and PLake transparency

•Nutrient cycling leads growth and productivity of primary producers•Regulates and influences the oxygen levels. •Oxygen is necessary for respiration of aquatic animals and for excluding P from leaching out of the soil.

Page 4: Melinda Lamb

Reed canarygrassCreates dense monospecific standsLimits light availability, water, and nutrients Known to reduce habitat for ground nesting

birds due to dense compositionReduces tree seed recruitment by

monopolizing light and creating a dense canopy

Loves cool, wet places but can and will tolerate a wide range of habitats including hot and dry.

Page 5: Melinda Lamb

Reed canarygrass alters lake functions

Nutrient cycling Water consumptionIncreased

sedimentation yeilding water diversion

Disolved Organic Carbon (DOC) levels

Page 6: Melinda Lamb

High Rate of Decompostition and N and P Leaching (Kao et al. 2003)Rank Species N Retention (g

N m22) Species P Retention (g

P m22)1 S. americanum 9.7 J. effusus 1.3

2 J. effusus 9.3 S. americanum 0.9

3 S. cyperinus 7.1 C. canadensis 0.49

4 C. canadensis 4.7 S. cyperinus 0.46

5 P. arundinacea 3.3 P. arundinacea 0.2

Table 2. Net shoot retention of N and P estimated for the five species in rank order. Recreated from Kao 2003

Page 7: Melinda Lamb

Leaching results from Kao et al. 2003 Figure 5. Percentages of a) nitrogen and b) phosphorus retainedin shoot litter after 60, 120, and 150 days of decomposition.Means for Scirpus (triangle), Juncus (diamond),Calamagrostis (square), Sparganium (X) and Phalaris (circle)are shown with standard errors for 5 replicates. Therewere no significant results for 60 and 120 days.

Page 8: Melinda Lamb

Water Consumption/Sedimentation Deposition

Page 9: Melinda Lamb

Changes to DOCVegetation compositions yeild significantly

different BDOC concentrations in runoff (Fellman 2006)

Watershed composition of forested wetland linked to DOC levels (Xenopoulos 2003)

Lake shoreline composed of wetland, is linked to DOC levels (Xenopoulos 2003)

Page 10: Melinda Lamb

ConclusionReed canarygrass can lead to a high nutrient

runoff events, lower DOC levels and lower water circulation.

Reed canarygrass can contribute the eutrophication of lakes although it has been traditionally thought to be a plant used to prevent eutrophication.

The effects will be more obvious in shallower, lower volume lakes with more complexity in the shoreline development.

Page 11: Melinda Lamb

Brown, P. D, Wurtsbaugh, W. A., Nydick, K. R. 2008. Lakes and Forests as Determinants of Downstream Nutrient Concentrations in Small Mountain Watersheds. Arctic, Antarctic, and Alpine Research. 40: 462-469.

Lavergne, S., Molofsky, J. 2004. Reed Canary Grass (Phalaris arundinacea) as a Biological Model in the Study of Plant Invasions. Critical Reviews in Plant Sciences. 23: 415-429.

Lefor, M. W. 1987. Phalaris arundinacea L. (reed canary grass, Gramineae) as an hydrophyte in Essex, Connecticut, USA. Environmental Management. 11: 771-773

Martina, J., von Ende, C.. Correlation of soil nutrient characteristics and reed canarygrass (Phalaris arundinacea: Poaceae) abundance in Northern Illinouis (USA). Am. Midl. Nat. 160:430-437.

Kao, J., Titus, J., Zhu, W.. 2003. Differential Nitrogen and Phosphorus Retention by five wetland plant species. Wetlands. 23: 979-987.

Xenopoulos, M., Lodge, D., Frentress, J., Kreps, T., Bridgham, S., Grossman, E., Jackson, C. 2003. Regional comparisons of watershed determinants of dissolved organic carbon in temperate lakes from the Upper Great Lakes region and selected regions globally. Limnology and Oceanography. 48: 2321-23334.