Determining Reference Conditions for Southwestern Ponderosa Pine Forests

Determining Reference Conditions for Southwestern Ponderosa Pine

Forests

GOALS FOR LECTURE

1. You will be able to define ecological restoration.

2. You will be able to define reference conditions and how reference conditions are determined.

3. You will be able to discuss reference conditions in the context of southwestern ponderosa pine forests.

WHAT IS ECOLOGICAL RESTORATION???

What is Ecological Restoration?

The Society of Ecological Restoration (SER) defines ecological restoration in its mission statement as “the process of assisting the recovery and management of ecological integrity. Ecological integrity includes a critical range of variability in biodiversity, ecological processes and structures, regional and historical context, and sustainable cultural practices” (Society for Ecological Restoration 1996).

Need to identify ecological restoration goal, identify the restoration potential of a site, how to conduct the restoration, and how to evaluate the success of restoration.

* REFERENCE CONDITIONS

Ecological Restoration

The range of historical or natural variability in ecological structures and processes that reflect evolutionary history, disturbance regimes, and abiotic and biotic conditions (Covington et al. 1997).

Reference Conditions

HOW DO YOU DETERMINE REFERENCE

CONDITIONS???

PONDEROSA PINE•Ponderosa pine (Pinus ponderosa) trees grow in every state found west of the Great Plains

•In Colorado, ponderosa pine trees are commonly found on mesas to the montane from 5,000-9000 ft

•In the San Juan Mountains, pure stands of ponderosa pine can be found on sandstone substrates from 6,500-8,000 ft

Drawing by Robert Petty in “Graced by Pines” 1994

PONDEROSA PINE

PONDEROSA PINE

HISTORICAL DATA

WRITTEN RECORDS

Lt. Edward Beale, 1857 (northern Arizona) “A vast forest of gigantic pines, intersected frequently with open glades, sprinkled all over with mountains, meadows, and wide savannas, and covered with the richest grasses, was traversed by our party for many days.”

C. DuBois, 1903 (San Juan Mountains) “Throughout the [“bull” or ponderosa pine] type there is good cattle range, consisting of blue-stem grass beneath the trees and bunch grass in the parks. The underbrush is very heavy, chiefly oak brush, choke-cherry, scarlett thorn, and wild rose. Reproduction of bull pine is poor.”

PHOTOGRAPHS

Courtesy of Cline Library Special Collections, Northern Arizona University

1911

1928

1985

RESEARCHWoolsey 1910 Forest Stand Inventory

DBH CLASS DBH RANGE 1985/87 1962 1910

6 4.6-7.5 68.0 45.0 6.39 7.6-10.5 36.1 21.8 3.2

12 10.6-13.5 18.1 11.1 2.5

15 13.6-16.5 8.8 6.6 2.2

18 16.6-19.5 4.5 4.0 2.0

21 19.6-22.5 2.3 * 1.8

24 22.6-25.5 1.3 * 1.4

27 25.6-28.5 0.6 * 0.7

30 28.6+ 0.4 0.6 0.8

TOTAL  140.0 93.6 20.8

CONTEMPORARY DATA

FIRE SCARS

EURO-AMERICAN SETTLEMENT

GRAZING LOGGING FIRE SUPPRESSION

LOS ALAMOS

OTHER CONTEMPORARY DATA

*SPECIES COMPOSITION AND STRUCTURE

*SOIL SEED BANK

*BIOTIC AND ABIOTIC SOIL CHARACTERISTICS

*DEAD/DOWN WOODY MATERIALS

*TRADITIONAL ECOLOGICAL KNOWLEDGE

REFERENCE CONDITIONS SOUTHWESTERN PONDEROSA PINE

Fire- Key disturbance that regulates ponderosa pine forests

*Low intensity fires (2-20 year interval)

*Large diameter trees interspersed with grassy meadows

*Diverse, productive herbaceous understory

WHO USES THIS INFORMATION?

Governmental Agencies-National Park Service, Forest Service, BLM

State and Local Government- e.g., Montezuma County (Ponderosa Pines Project), Boulder Mountain Parks

Conservation Organizations-The Nature Conservancy, Grand Canyon Forest Trust

General Public-e.g., where to build a house (fire-prone environment, floodplain, etc.), where to recreate, forming opinions on public land management actions

GOALS FOR LECTURE

1. You will be able to define ecological restoration.

2. You will be able to define reference conditions and how reference conditions are determined.

3. You will be able to discuss reference conditions in the context of southwestern ponderosa pine forests.

QUESTIONS??

Tree Canopy Data for the Gus Pearson

Natural Area, Arizona for 1876 and 1990

Four Main Components:1) Cultural * Native Americans played an important role in

the evolutionary history of many ecosystems through their interactions with the natural world.

* Native Americans used fire as a tool for hunting, promoting/discouraging specific plant species which differs from lightning fires in seasonality, frequency, and intensity.

Components of Ecological Restoration

Four Main Components:2) Economical * How much will the restoration project cost to

plan, implement, and monitor?

* What are the economical benefits from restoration (immediate and long-term)?

Components of Ecological Restoration

Four Main Components:3) Social * Need to look at restoration as an outcome of

complex interactions between nature and society and divergent social and political views within society.

* Need to develop common ground among all participants when identifying and planning restoration projects.

Components of Ecological Restoration

Four Main Components:4) Ecological * Need to identify ecological restoration goal,

identify the restoration potential of a site, how to conduct the restoration, and how to evaluate the success of restoration.

* Need to identify a spatial and temporal context

for ecological restoration.

* REFERENCE CONDITIONS

Components of Ecological Restoration