In what way isa cross section ofa tree trunk a record of climatic conditions?

Question

What factors seem to account for the rise of water in tall trees? In what different ways are leaves designed to get rid of excess water?

Answer 1

1. The xylem ring size will tell you if there was abundant water and minerals for growth. The thicker the rings the more materials were available; the thinner the tree had a hard time getting what it needed to grow.

2. a). water exits leaf through stomata.
b). this water loss is replaced by evaporation from mesophyll cells, lowering their water potential, causing them to take water from neighboring cells.
c). the process connects back to the tracheids causing water to be taken from the xylem.
d).Water travels from the tracheids to the air following a water potential gradient.
e). Waters cohesive and adhesive properties and the small diameter of xylem aid in its movement of up the tube.
f). This pull decreases water pressure in the xylem causing the roots to take water from the soil.

3. All water leaves the plant throught the leaves stomata. These are located on the lower surface of the leaf blade.

Answer 2

When climate conditions are good (plenty of rain mainly), a tree grows faster and produces a wider, more corky ring that is lighter in color. Each annual ring on a tree has a dark and a light portion. The darker portion is from the slower growing part of the year (usually winter) and the lighter is the fast growing season. Both together equals a year. You can compare the relative width of the annual rings from year to year to see what years the tree grew more (hence wetter and warmer or sunnier).

There is a great discussion about what forces are responsible for the rise of water in trees at this website:
http://waynesword.palomar.edu/trjuly99.htm. There's still quite a bit of debate on this issue.

Besides the pores (stomata) that release internal water from leaves, some leaves are also designed to be able to shed excess water on their surface. This is especially true of rain forest species. Many of them have splits in the leaves or small grooves that act like gutters to get the water to run off.

Answer 3

Each ring on the tree represent a year of growth.A bigger ring means the tree grew a lot during that season Which means the climate conditions(Sun and water) must have been right.

There for if there were say a patter of 5 small rings to 3 larger rings,you could say that every 3 years or so there is a 5 year drought.

The rise was water in the plant is mostly fro the sir temperature.More water that is 'evaporating' from the tree than is going in will mean the plant is wilting.

Leaves 'breath'.When we breath,water is also expelled out.

Answer 4

A. In good years - adequate rain, suitable temperatures - there became good growth, with wider rings. In very dry or very chilly years, the tree struggled greater good to outlive, with poorer growth and narrower rings