# Association of ectomycorrhizal mats with Pacific yew and other understory trees at the Andrews Experimental Forest and the southern and western Cascades, Oregon, 1992-1994

## Dataset

- **Database Code:** SP022

- **Title:** Association of ectomycorrhizal mats with Pacific yew and other understory trees at the Andrews Experimental Forest and the southern and western Cascades, Oregon, 1992-1994

- **Abstract:**

This study was designed to determine if ectomycorrhizal mats are more likely to be present in soils at the base of common understory trees than in soils distant from trees and to determine if there is a relationship between the occurrence of mats and tree size. The understory trees studied included the Pacific yew (Taxus brevifolia Nutt.) western hemlock (Tsuga heterophylla (Raf.) Sarg) and vine maple (Acer circinatum Pursh). Twelve sites were studied representing a range of climatic conditions and management histories. More than 2,900 plots were surveyed over an 18-month period. It was found that the incidence of ectomycorrhizal mats was higher at the base of all three species of trees when compared with control plots. A statistically significant positive correlation was also observed between the incidence of mats and tree size. When comparing saplings with larger trees, the saplings consistently had a lower incidence of mats. These observations are not consistent with the hypothesis that ectomycorrhizal mats are required for T. brevifolia establishment or survival.


- **Keywords:** primary production; inorganic nutrients; mycorrhizae; Long-Term Ecological Research (LTER); primary production; inorganic nutrients

- **Temporal coverage:** 1992-01-07 to 1994-01-07

- **Principal Investigator:** Robert P. Griffiths


## Data Entities

1. SP02201

## Entity 1: SP02201

### Attribute list

- **SITE** — numeric(1.000000), range  1.0000  50.0000, number

Sample site number


- **PLOT** — numeric(1.000000), range  1.0000  16.0000, number

Plot number within sample site


- **TREE** — numeric(1.000000), range  1.0000  1250.0000, number

Sequential tree number


- **TREE_TYPE** — varchar, freetext

Type of sample tree (HEMLOCK, MAPLE, OTHER,YEW)


- **SAPLING** — varchar, freetext

Is tree a sapling (YES/NO)


- **CIRCUM** — numeric(0.100000), range  0.0000  400.0000, centimeters

Circumference of tree


- **TREEMAT** — varchar, freetext

Is there a mat associated with the tree? 0=no, 1=yes


- **CONTMAT** — varchar, freetext

Is there a mat associated with the control? 0=no, 1 = yes


- **TREEHYST** — varchar, freetext

Is there a hysteragium mat associated with the tree? 0=no, 1=yes


- **CONTHYST** — varchar, freetext

Is there a hysterangium mat associated with the control? 0=no, 1=yes


- **TREEGAUT** — varchar, freetext

Is there a gautieria mat associated with the tree? 0=no, 1=yes


- **CONTGAUT** — varchar, freetext

Is there a gautieria mat associated with the control? 0=no, 1=yes


- **TREEPILO** — varchar, freetext

Is there a piloderma mat associated with the tree? 0=no, 1=yes


- **CONTPILO** — varchar, freetext

Is there a piloderma mat associated with the control? 0=no, 1=yes


## Attribute Definitions

**CIRCUM**

Circumference of tree


**CONTGAUT**

Is there a gautieria mat associated with the control? 0=no, 1=yes


**CONTHYST**

Is there a hysterangium mat associated with the control? 0=no, 1=yes


**CONTMAT**

Is there a mat associated with the control? 0=no, 1 = yes


**CONTPILO**

Is there a piloderma mat associated with the control? 0=no, 1=yes


**PLOT**

Plot number within sample site


**SAPLING**

Is tree a sapling (YES/NO)


**SITE**

Sample site number


**TREE**

Sequential tree number


**TREEGAUT**

Is there a gautieria mat associated with the tree? 0=no, 1=yes


**TREEHYST**

Is there a hysteragium mat associated with the tree? 0=no, 1=yes


**TREEMAT**

Is there a mat associated with the tree? 0=no, 1=yes


**TREEPILO**

Is there a piloderma mat associated with the tree? 0=no, 1=yes


**TREE_TYPE**

Type of sample tree (HEMLOCK, MAPLE, OTHER,YEW)