Some Basic Concepts For Managing Land Dr. Karl Wood, Director Water Resources Research Institute Stucky Hall New Mexico State University

Suppose you have just acquired some land! What is the climate? What is the topography? What plants and animals are present? What is the soil condition? What are the goals for land? What is it capable of growing? Are the goals ecologically, socially, and economically feasible? Some questions need to be answered:

To answer these questions, some scientific understanding is needed.

Sunshine Water Minerals Nutrients Primary Producers Plants 6000 cal/m 2 /yr Plants Primary Consumers Mice 600 cal Sheep Secondary Consumers Snake 60 cal Wolf Tertiary Consumer Eagle 6 cal Decomposers heat Trophic Energy Pyramid Example Based on Second Law of Thermodynamics

Exploitation Sustainable Protection Use Land Goal? The extremes result in attitudes of supremacy From: Thompson, P.B The Spirit of the Soil - Agriculture and Environmental Ethics. Routledge Publ. New York, New York

Concept of the Sere Bare Rock Lichens Soil depth and richness Climate Time Example developed in North America by H.C. Cowles and F.E. Clements about 100 years ago

Example of a lichen & associated animals

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Time

Example of a moss & associated animals

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annual grasses and forbs Time

Example of annual grasses and forbs & associated animals

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annual grasses and forbs Perennial grasses and forbs Time

Examples of perennial grasses and forbs & associated animals

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annual grasses and forbs Perennial grasses and forbs Shrubs Time

Example of shrubs & associated animals

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annual grasses and forbs Perennial grasses and forbs Shrubs Deciduous trees Time

Example of deciduous trees & associated animals

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annual grasses and forbs Perennial grasses and forbs Shrubs Deciduous trees Time Conifers

Example of conifers growing through deciduous forest

Example of conifers & associated animals

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annual grasses and forbs Perennial grasses and forbs Shrubs Deciduous trees Conifers Climax Time Each level Is called a “seral stage”

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annual grasses and forbs Perennial grasses and forbs Shrubs Deciduous trees Conifers Climax Time Primary Succession Retrogression Secondary succession

The kinds of animals are different in each seral stage. The climax seral stage usually does not represent the greatest species diversity of plants and animals. Subclimax seral stages may be maintained by continuous or discontinuous perturbations such as fire, grazing, hurricanes, etc. Movement towards climax is called succession Movement away from climax is called retrogression (e.g. Desertification) Multiple equilibrium communities and complex successional pathways may be possible within a sere. General Comments On Ecosystem Succession

To manage an ecosystem, managers need to know: 1. What is the potential or climax seral stage of the area? 2. What is the present seral stage of the area? Is it all the same or are there different seral stages in different parts of the area? 4. Can the preferred seral stage be achieved with the present technology, time, legal, political, and economic constraints? 3. Are there several acceptable seral stages and a preferred seral stage of the area and/or its parts?

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annuals Time Most choices are here! Conifers Deciduous trees Shrubs Perennial grasses and forbs

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annuals Time What seral stage Has the most Plant and animal Diversity? Conifers Deciduous trees Shrubs Perennial grasses and forbs

Diversity (number of plant & animal Species) Bare Rock Climax Seral Stage

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annuals Time Can the Seral stage Ever be above Climax? Conifers Deciduous trees Shrubs Perennial grasses and forbs

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annuals Time Yes! Deciduous trees Artifical inputs of water and nutrients (Fertilizer) Example: Perennial grasses and forbs(Desert grasslands) (Pecan orchard) Must have adequate soil depth!

Concept of the Sere Bare Rock Lichens Mosses Soil depth and richness Climate Annual grasses and forbs Perennial grasses and forbs Time When retrogression occurs, increased erosion rates can be expected. Example: Native Great Plains Converted to cropland (corn, soybeans, wheat, cotton)

Nature abhors a void Nature abhors topographical prominence Nature abhors a crowd Natural changes are often dynamic and catastrophic with unpleasant consequences for humans Changes in nature due to human activities may be dynamic and catastrophic, or static, controlled, predictable, and beneficial to humans, animals, and the land where they live. Human influence is most probable for avoiding catastrophes and assuring ecological, social, and economic stability. Conclusions

Healthy Land = preferred seral state is attained Sustainability = preferred seral stage is maintained against the processes of succession and retrogression, including invasions, especially by exotics Conclusions

God bless America! And Pistol Pete!

Thank you!