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Ailanthus altissma- Plant Tissues (Winter, 1999) |
This shows that the highest
concentrations of calcium (Ca) occur in bark. Twigs have a
larger surface area (of bark) to volume ratio than larger
branches and thus have more calcium by weight. To a lesser
extent, this pattern is followed by the other three
nutrients- magnesium (Mg), potassium (K), and phosporus (P).
The nutrients must be contained in the cell walls of the
phloem vessels and vascular cambium rather than in the wood
or xylem vessels. The phloem vessels and vascular cambium
occur just under the bark.
Copper (Cu) and zinc (Zn) appear to
concentrate in the newest growth, the twigs. Iron (Fe) and
manganese (Mn) follow the pattern of calcium, magnesium, et
al with high concentrations in bark and twigs.
Diameter at Breast Height (DBH) is correlated to the total amount of copper, manganese, iron, and zinc in the Ailanthus tree on Saltonstall Ridge. The above graph shows that the quantity of these elements increases proportional to the incease in DBH.
Although this graph shows a dramatic increase in the concentration of all four nutrients (Ca, Mg, K, and P) at or before a DBH of at least 22 cm, the following line graph shows in better detail the more exponential rise in concentration of the nutrients.
The above graph (Concentration of Cu,
Mn, Fe, Zn versus DBH for Ailanthus altissma at Saltonstall
Ridge 1999) shows the relationship between the concentration
of four elements and DBH. You can see that the concentration
of iron increases precipitously between a DBH of 6 cm and 10
cm. For Cu, Mn, and Fe, the graph suggests that the
concentrations rapidly increase with DBH and then gradually
levels off. Zinc, however, has a less dramatic profile. It
is important to note that we need more data points
(especially from trees with larger DBHs than 25 cm) to
further test this hyphothesis.
*= upper slope of various Hubbard Brook Watersheds
This graph compares the concentrations of Ca and Mg growing on Saltonstall Ridge to different tree species at Hubbard Brook. At first glance, Ailanthus (AILA) appears to have the highest concentrations of both elements. However, the parent material may influence the Ca and Mg concentrations more than the species difference. The parent rock at Saltonstall Ridge is basalt whereas granite underlies the Hubbard Brook watersheds. According to data gathered by the 1996 Methods Class, a sugar maple growing on arkosic parent material has concentrations in the high 800s for Ca--similar to the Tree of Heaven. Neither of the soils formed above the arkose or basalt is as acidic as the soils of Hubbard Brook.
TREE COMPARISON
WITH HUBBARD BROOK TREE
CHEMISTRY
TREE SPECIES ABBREVIATION [Ca] wood
(ppm) [Mg] wood
(ppm) ASH (bird
plots) ASH SUGAR MAPLE (wet
site) SM YELLOW BIRCH (wet
site) YB FIR (high
altitude) FIR* SPRUCE (high
altitude) SP* WHITE BIRCH (high
altitude) WB* YELLOW BIRCH (high
altitude) YB* BEECH BE 694 TREE OF HEAVEN AILA
