Environmental Engineering Reference
In-Depth Information
Table 3.5 Examples of techniques used for quantifying product yield
Variable
Methodology
Ground-level traps. Four isolated selected 15
1m
2
plots randomly located beneath crown.
Fruit yield per
season
Number of intact, predated, immature, and mature fruit recorded every 7-10 days in plot
Fruit yield per
Fruit counted
in situ
on sample trees at frequent (weekly) intervals. Counted fruit marked
season
with paint to avoid repeated counts
Fruit, leaves,
Randomized branch sampling. Branching pattern defined as numbered segments between
etc.
branch nodes. Path from trunk to branch tip selected using random selection at each node.
Fruit, leaf, etc. counts undertaken at distal end of path. Pooled results from several
randomly selected branches are a non-destructive, precise, and statistically reliable
method of estimating fruit yield of tree. There are several refinements of method,
e.g. path selection proportional to size of available segments at a node, etc.
Leaves
Pipe model. Non-destructive regression technique for estimating leaf biomass and area
from branch cross-sectional area. Pipe model based on observation that transpiration
rate of canopy is proportional to leaf area, sapwood cross-sectional area, and
conductivity of water-transporting tissue. Therefore size of stem is proportional to leaf
mass and area. So leaf and area can be estimated by measurement of stem cross-sectional
area (NB: needs to be very accurate - mm). Sample branches selected systematically
to represent different branch heights. Regression analysis without constant
