Table 1. Spatial characteristics of tree locations and tree dbhs at 0–50 m distances.
| Species name | Lightshade | Canopyundergrowth | L function at 0–50 m | Marked point pattern at different distances | ||
| Homogeneous Poisson model (HomP) | Random labeling model (RLM) | Heterogeneous Poisson model (HetP) | ||||
| Betula platyphylla | L | C | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–6 (−) |
| Acer mandshuricum | L | C | 0–50 (+) | 0–50 (−) | 0–32 (−) | 0–42,47–50 (−) |
| Syringa reticulata var. amurensis | L | U | 0–50 (+) | 0–7 (−) | 0–11 (−) | 0–10 (−) |
| Euonymus macropterus | L | U | 0–50 (+) | 20–28 (+) | 0–16,20–29 (+) | 0–15,20–30,39–46 (+) |
| Padus racemosa | L | U | 0–50 (+) | 8–26,41–50 (−) | 0–26 (−) | 0–27 (−) |
| Abies nephrolepis | S | C | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–50 (r) |
| Ulmus davidiana var. japonica | L | C | 0–50 (+) | 0–50 (r) | 0–3 (−) | 0–8 (−) |
| Acanthopanax senticosus | S | U | 0–50 (+) | 0–50 (r) | 0–5 (+),35–50 (−) | 0–15 (+),35–50 (−) |
| Acer barbinerve | S | U | 0–50 (+) | 22–29,32–34,42–50 (−) | 44–50 (–) | 43–50 (−) |
| Ulmus macrocarpa | L | C | 0–50 (+) | 0–50 (r) | 0–15 (−) | 0–15 (−) |
| Philadelphus schrenkii | M | U | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–50 (r) |
| Betula costata | L | C | 0–50 (+) | 0–5 (−) | 0–7 (−) | 0–7 (−) |
| Betula dahurica | L | C | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–2 (−) |
| Cerasus maximowiczii | S | U | 0–50 (+) | 0–22 (+) | 0–19 (+) | 0–20 (+) |
| Pinus koraiensis | L | C | 0–50 (+) | 41–50 (−) | 0–5,17–22,41–50 (−) | 0–5,15–25,35–50 (−) |
| Juglans mandshurica | L | C | 0–50 (+) | 0–2 (−) | 0–6 (−) | 0–6 (−) |
| Acer ukurunduense | L | U | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–50 (r) |
| Sorbus pohuashanensis | L | U | 0–50 (+) | 0–50 (r) | 0–10 (−) | 0–12 (−) |
| Fraxinus rhynchophylla | L | C | 0–50 (+) | 0–50 (r) | 36–42 (−) | 0–50 (r) |
| Phellodendron amurense | L | C | 0–50 (+) | 48–50 (+) | 0–50 (r) | 0–50 (r) |
| Lonicera praeflorens | M | U | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–50 (r) |
| Lonicera maackii | L | U | 0–50 (+) | 39–50 (+) | 0–14 (−) | 0–17 (−) |
| Tilia mandshurica | L | C | 0–50 (+) | 0–50 (r) | 18–45 (−) | 18–45 (−) |
| Ulmus laciniata | L | C | 0–50 (+) | 0–50 (−) | 0–50 (−) | 0–50 (−) |
| Euonymus pauciflorus | L | U | 0–50 (+) | 5–14,19−26 (+) | 0–26 (−) | 0–26 (−) |
| Aralia elata | M | U | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–50 (r) |
| Corylus mandshurica | S | U | 0–50 (+) | 15–50 (−) | 17–26,48–50 (−) | 17–50 (−) |
| Quercus mongolica | L | C | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–50 (r) |
| Carpinus cordata | L | C | 0–50 (+) | 0–50 (−) | 0–41 (−) | 0–45 (−) |
| Acer tegmentosum | S | U | 0–50 (+) | 0–50 (r) | 0–4 (−) | 0–4 (−) |
| Acer mono | L | C | 0–50 (+) | 0–24 (−) | 0–19 (−) | 0–24 (−) |
| Abies holophylla | S | C | 0–50 (+) | 3–8 (−) | 0–12 (−) | 0–12 (−) |
| Rhamnus davurica | S | U | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–50 (r) |
| Fraxinus mandshurica | L | C | 0–50 (+) | 0–50 (r) | 0–4 (−) | 0–4 (−) |
| Sorbus alnifolia | M | C | 0–50 (+) | 0–50 (r) | 0–50 (r) | 0–50 (r) |
| Populus koreana | L | C | 0–50 (+) | 0–50 (r) | 36–46 (−) | 4–7,36–46 (−) |
| Tilia amurensis | L | C | 0–50 (+) | 0–50 (r) | 3–11 (−) | 3–11 (−) |
Note: L means light; S means shade and M means middle. C means canopy trees and U means understory.
Spatial point patterns were tested for randomness using the L-function. The spatial characteristics of tree dbhs were analyzed by the homogeneous Poisson (HomP), random labeling (RLM) and heterogeneous Poisson (HetP). Spatial distances at which tree locations show significant aggregation, regularity and randomness are indicated by the symbols “+” in parenthesis in L-function. Spatial distances at which tree locations and tree dbh marks show significant positive, independent and negative correlation are indicated by the symbols “+”, “r” and “−” in parenthesis, respectively.