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A related variable which is often used in agronomy is the 'Harvest index'. Because roots are seldom harvested, the harvest index is the amount of marketable product (often the seeds), relative to the total above-ground biomass. Alternative terminology that has been used are Leaf, Stem and Root Mass Ratios, or shoot:root or root:shoot ratios.
Stand density index (SDI; also known as Reineke's Stand Density Index [1] after its founder) is a measure of the stocking of a stand of trees based on the number of trees per unit area and diameter at breast height (DBH) of the tree of average basal area, also known as the quadratic mean diameter. It may also be defined as the degree of ...
The equation for exponential mass growth rate in plant growth analysis is often expressed as: = Where: M(t) is the final mass of the plant at time (t). M 0 is the initial mass of the plant. RGR is the relative growth rate. RGR can then be written as:
In 2018, Bar-On et al. estimated the total live biomass on Earth at about 550 billion (5.5×10 11) tonnes C, [1] most of it in plants. In 1998 Field et.al. estimated the total annual net primary production of biomass at just over 100 billion tonnes C/yr. [ 4 ] The total live biomass of bacteria was once thought to be about the same as plants ...
where A is the area of a given leaf or all leaves of a plant, and M L is the dry mass of those leaves. Typical units are m 2 /kg or mm 2 /mg. Leaf mass per area (LMA) is its inverse and can mathematically be decomposed in two component variables, leaf thickness (LTh) and leaf density (LD): [4] = =.
Plant density is the number of individual plants present per unit of ground area. It is most easily interpreted in the case of monospecific stands, where all plants belong to the same species and have germinated at the same time. However, it could also indicate the number of individual plants found at a given location.
Leaf area index (LAI) is a dimensionless quantity that characterizes plant canopies. It is defined as the one-sided green leaf area per unit ground surface area (LAI = leaf area / ground area, m 2 / m 2) in broadleaf canopies. [1] In conifers, three definitions for LAI have been used: Half of the total needle surface area per unit ground ...
Site index is a term used in forestry to describe the potential for forest trees to grow at a particular location or "site". Site is defined as "The average age of dominate and/or codominate trees of an even-aged, undisturbed site of intolerant trees at a base age"; [1] furthermore, the word site is used in forestry to refer to a distinct area where trees are found. [2]