Ecological Archives A014-012-A1

Jeffrey R. Dunk, William J. Zielinski, and Haiganoush K. Preisler. 2004. Predicting the occurrence of rare mollusks in northern California Forests. Ecological Applications 14:713–729.

Appendix A. Candidate explanatory variables used to model mollusk presence–absence in northern California National Forests, 1999–2000.

Physical/Climatic
Acronym

Annual temperature

ANNTMP

Annual precipitation

PPT

Coefficient of variation of December and July precipitation
(a measure of seasonal variability in precipitation)

CVPRE

Summer precipitation

SMRP

Summer temperature

SMRTMP

Moisture stress index relating summer temperature and precipitation

SMRTSMRP

August maximum temperature

AUGMAXT

December minimum temperature

DECMINT

Difference between August maximum and December

 

Minimum temperatures

DIFTMP

Percent slope

SLP

Transformed aspect

TASP

Elevation

EL

   
Spatial

 

UTM east

EAST

UTM north

NORTH

   
Vegetation from FIA plots

 

Percentage total canopy cover

TC

Percentage canopy cover of conifers

CC

Percentage canopy cover of hardwoods

HC

Percentage shrub cover

SC

Percentage forb cover

FC

Percentage grass cover

GC

Percentage grass + forb cover

GFC

Total basal area

BA

Basal area of conifers

CBA

Basal area of hardwoods

HBA

Basal area of Quercus spp.

QBA

Basal area of Acer spp.

ABA

Mean age of trees in plot

AGE

Standard deviation (SD) of tree age

SAGE

Volume of downed wood

TWD

Volume of large (>25.4 cm diameter at base) downed wood

LRGWD

Volume of small (<25.4 cm diameter) downed wood

SMLWD

Mean tree diameter at breast height (dbh)

DBH

SD of tree dbh

SDBH

Mean dbh conifers

CDBH

SD dbh conifers

SCDBH

Mean dbh hardwoods

HDBH

SD dbh hardwoods

SHDBH

Mean tree height

HT

SD tree height

SHT

Mean height conifers

CHT

SD height conifers

SCHT

Mean height hardwoods

HHT

SD height hardwoods

SHHT

   
Mesoscale variables

 

Hectares of plantation

PL

Hectares of young/early mature conifers

YC

Hectares of young/early mature conifers, low density

YCL

Hectares of hardwoods

HD

Hectares of late-seral conifer dominated

LC

Hectares of late-seral, low density, conifer dominated

LCL

Hectares of late-seral hardwood dominated

LHD

Meters of blue-lined stream

STR

Meters of road

RD



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