Tree Population Dynamics in the West Twin Creek Watershed: Tree Population Dynamics, Growth and Mortality in Old-Growth Forests in the Western Olympic Mountains, Washington

Metadata:

Identification_Information
Data_Quality_Information
Spatial_Data_Organization_Information
Spatial_Reference_Information
Entity_and_Attribute_Information
Distribution_Information
Metadata_Reference_Information

Identification_Information:

Data_Quality_Information:

Lineage:

Methodology:

Methodology_Type: Field

Methodology_Identifier:

Methodology_Keyword_Thesaurus: None
Methodology_Keyword: vegetation sampling

Methodology_Description:

Forty-one trees were cored with an increment borer and aged at breast height. The forest is uneven aged. Douglas-fir, western red cedar, western hemlock, and Pacific silver fir trees ranged in age from 237 to 635, 123 to 600, 71 to 262, and 98 to 248 years, respectively. The stands in the lower watershed probably originated after a major disturbance (or disturbances), perhaps fire, more than 600 years ago. Stand-replacement fires typically occur at greater than 500-year inter- vals in this area (Agee and Huff 1987). Trees in the upper watershed also probably originated after a major disturbance, but this is difficult to date. The age range of Douglas-fir probably resulted from slow establishment after initial stand replacement disturbance and subsequent smaller disturbances, allowing establishment of this intolerant species. Maximum tree diameters at breast height (DBH) in the watershed were 310, 302, 260 and 190 cm for Douglas-fir, western red cedar, western hemlock, and Pacific silver fir, respectively. The tallest trees are >90 m in height but the canopy is broken up and very uneven. Determination of tree species composition, diameter distributions, canopy classes, mortality, and seedling recruitment. Six permanent circular vegetation sample plots (1000 m2) were located in the West Twin Creek watershed, with three plots in the lower watershed (at approximately 240 m elevation) and three plots in the upper watershed (at approximately 750 m elevation). species and DBH were determined on each plot in 1985 and 1990. Trees >5 cm DBH were placed in 20-cm diameter classes. In 1985 number and species of trees with diameters <5 cm DBH were deter- mined on four randomly located 25-m' plots within each of the larger plots. No ingrowth from the <5 cm diameter class to the 5-24.9 cm diameter Class one tree at Hoh Lake. In each plot trees were subjectively assigned a canopy class (sub-canopy, intermediate, codominant, and dominant). DBH ranges (cm) at each watershed and for each class were as follows: Lower Watershed: Subcanopy: 5-34; Intermediate: 17-59; Codominant: 38-106; Dominant: 74-195. Upper Watershed: Subcanopy: 5-24; Intermediate: 9-51; Codominant: 34-144; Dominant: 87-134. Tree mortality and likely causes were determined annually from 1985-1990.

Spatial_Data_Organization_Information:

Indirect_Spatial_Reference:: West Twin Creek watershed on the Olympic Peninsula, Washington, USA

Spatial_Reference_Information:

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label:: Population and mortality of trees <5 cm in diameter by species and canopy class in the lower and upper West Twin Creek watershed, 1985-1990

Attribute:

Attribute_Label: name of species

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Abies amabilis

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Pseudotsuga menziesii

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Thuja plicata

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Tsuga heterophylla

Attribute:

Attribute_Label: Canopy class

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: dominant

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: codominant

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: intermediate

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: subcanopy

Attribute:

Attribute_Label: individuals/ha

Attribute_Definition: number of trees of a given species in a given year

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1985

Attribute:

Attribute_Label: deaths/ha

Attribute_Definition:

number of trees of a given species dead from 1985-1990

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1990

Attribute:

Attribute_Label: deaths as % of cohort

Entity_Type:

Entity_Type_Label:: Number of trees per hectaire by diameter class and species in the lower and upper West Twin Creek watershed, 1985

Attribute:

Attribute_Label: diameter class (cm)

Attribute:

Attribute_Label: tree species

Attribute:

Attribute_Label: lower watershed

Attribute:

Attribute_Label: upper watershed

Entity_Type:

Entity_Type_Label:: Causes of tree death in permanent plots in the West Twin Creek watershed, 1985-1990

Attribute:

Attribute_Label: Primary cause of death

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: suppression-unknown

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: disease-insects

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: wind

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: crushing

Attribute:

Attribute_Label: Number of trees dead

Attribute:

Attribute_Label: Percentage of trees dead from a particular cause

Entity_Type:

Entity_Type_Label:: Average diameter at breast height (DBH), basal area (BA), and net changes in basal area in the upper and lower West Twin Creek watershed by species and canopy class, 1985-1990

Attribute:

Attribute_Label: tree species

Attribute:

Attribute_Label: canopy class

Attribute:

Attribute_Label: average dbh (cm)

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1985

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1990

Attribute:

Attribute_Label: Basal area (m2ha-1)

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1985

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1990

Attribute:

Attribute_Label: Change in basal area (m2ha-1) 1985-1990

Distribution_Information:

Metadata_Reference_Information:

Generated by mp on Thu Aug 5 14:05:38 1999