{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lecture Oct 18th

Lecture Oct 18th - Organization distribution and diversity...

Info icon This preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
17/10/2010 1 Organization, distribution and diversity of Life in relation with environment - Terrestrial Biomes (Oki & Kanae Science 2006) Looking at the relationship between evapotranspiration and ‘runoff’ Small watershed experiments demonstrate the role of the vegetation in the relationship between ET and runoff. Hubbard Brook Ecosystem Study
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
17/10/2010 2 Experimental forest clearing and herbicide application reduced ET as seen in increased streamflow Vegetation plays a critical role in the hydrological balance between evapotranspiration and runoff … human activity plays a critical role in determining the nature of the vegetation cover. Land-use change, vegetation management and natural vegetation change have significant effects on the balance between ET and runoff . Mountain Pine Beetle Outbreak, BC Mountain pine beetle killed forest in B.C. - 35% tree mortality 22% increase in annual flow, 56% increase in spring runoff http://www.forrex.org/publications/streamline/ISS31/streamline_vol9_no2.pdf Forest plantations may increase ‘green water’ at the expense of ‘blue water’ Eucalyptus, Veracel, Brazil Eucalyptus, Tazmania In Australia, plantation owners must buy a water permit, in the same way as farmers who wish to withdraw water for irrigation How does evapotranspiration work?
Image of page 2
17/10/2010 3 Water flows in a continuous path from the soil, through plants and into the atmosphere Water moves from high water potential to lower water potential Generally, air is dry relative to the wet surfaces in the leaf, creating a large gradient in water energy potential which ‘pulls’ water from the leaf. The drier the air the stronger the force. Evapo-transpiration from the leaf surface via stomates draws water through the tree. When water is limited, stomates close, stopping gas flow.
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern