Fig 1.
Adapted from Shugart et al., 2020 [47], schematic showing how vegetation processes scale across space and time.
Grey boxes classify the biological and community scale. Yellow text describes leaf-based processes. Blue text describes endogenous processes. Red text describes exogenous disturbances and processes. The black dotted lines illustrate the current spatial and temporal scope of Earth System Models.
Fig 2.
A rudimentary simulation of a forest from bare soil for 600 years, using the continuous patch Eq (2) along with a toy gap model using a fixed 50x50 grid of patches on an arbitrary scale, and for a patch disturbance rate of λ = 0.01yr−1.
Panel (a) shows how the age-distribution of patches changes through time for both the gap and statistical model. (b) shows the time-evolving spatial age map for the 50x50 grid.
Fig 3.
Adapted from the work of Moore et al., 2018, 2020 [141, 142].
Best fits of Demographic Equilibrium Theory (DET), Eq (5), for μ0 (assuming z → d and ϕ → 1/3) against observations of number density versus diameter. Panel (a) shows the DET fit to North American trees [141] observations of trunk diameter (diameter at breast height) from the USDA Forest Service FIA program [143]. Panel (b) presents DET fits to RAINFOR measurements of basal diameter (b) [144]. μ1 is the normalised metric of the turnover parameter (μ0 at d0 = 1 cm) describing the shape of the Weibull distribution.
Fig 4.
Dynamic Global Vegetation Model (DGVM) trends through time.
Here models are categorized into three types: Average, Intermediate, and Complex. (1) Simple—plant size or age demographics are not included beyond the “average” case. (2) Intermediate—models include the representation of size and/or age within cohorts. (3) Complex—Individual Based models.