BEC Management Interpretations Indicator Plants

Management Interpretations, Examples u Species selection u Free-growing guidelines u Site Index (SIBEC), Productivity Class u Vegetation Potential u Site preparation u Silvicultural systems u Wildlife habitat (by species) u Sensitive ecosystem mapping and description u Rare plants u Cultural values u Minerals u Watershed values BEC Field Guides

Management Interpretations, Examples

Management Interpretations: Site Index u What is site index? For a particular target species, site index is the height of the largest diameter (at breast height) site tree on a 0.01 ha plot at breast height age 50 u Why is site index important for forest management? provides a numeric description of site productivity Silviculture prescriptions Projections of yield (Timber supply) Inventory projections

Management Interpretations: Site Index u How can we measure site index? Available tools suitable stands Growth Intercept Models Ages Height over age curves Ages SIBEC Ages 140

Management Interpretations: Site Index and Vegetation Potential u Old format Site class: I, II, III, IV Vegetation Potential: L, M, H, VH

Management Interpretations: Site Index Douglas-fir site index in CWHdm u New format based on SIBEC

Example from SIBEC tables

Management Interpretations Site Index of lodgepole pine across moisture regimes SBS zone

Interior Indicator Plants Amelanchier alnifolia Saskatoon, dry-moist Artemesia tridentata Big sage, dry-fresh Arnica cordifolia Heart-leaf arnica, fresh-moist

Basic indicator plant concepts u Based on niche concept, where each species is uniquely affected by a complex suite of environmental factors (site quality) u Ecological amplitude=niche breadth, which is usually measured by one or more factors (e.g., SMR, SNR)

Advantages of using the indicator plant concept u Quicker than detailed physical and chemical measures of site quality u Don’t fluctuate over short time periods u Integrate several factors that govern site quality (e.g., SMR depends on precip, radiation, moisture demands, soil properties that affect soil water storage capacity, etc.)

Ecological amplitude ≠ Physiological amplitude u Ecological amplitude=niche breadth, depends on competitive influence of neighbouring plants u Physiological amplitude=optimal growing conditions without competition; most plants grow best in fresh, rich, neutral soil u At extremes of ecological amplitude, plant are sporadic in cover and vigour is low (e.g., salal on stumps and CWD in wet, rich sites)

Ecological vs physiological amplitude of lodgepole pine SMR physiological amplitude ecological amplitude Coast: SMR physiological amplitude ecological amplitude Interior:

Attributes of good indicator plants u Narrow amplitudes u Limited to three contiguous classes u Plants with intermediate ranges also considered indicator plants (e.g., swordfern) u Should consider all indicator attributes (climate, SMR, SNR, substrate)

Local versus global indicators u Global: occurs across a wide range of indicator values (e.g., fireweed is a global indicator of exposed mineral soil in full light) u Local: restricted to a narrow range (e.g., salal is local indicator of cool mesothermal climates on acidic soils)

Indicator Groups=Differentiated group u Groups of species that have similar indicator values for particular indicator attributes

Indicator attribute: SMR u SMR=long-term balance between available soil water and plant water demand u Use actual SMR when choosing indicator plants u Actual SMR=based on actual annual water balance u Relative SMR: relatively driest in any climate to relatively wettest u Both actual and relative SMR can be classified into nine classes

SMR Indicator Groups, Coastal BC u MOIST 1: Lichen group, VX-X u MOIST 2: Kinnickinnick group, X-SM u MOIST 3: Oregon grape group, SM-M u MOIST 4: Deer fern group, M-SHG u MOIST 5: Salmonberry group, SHG-HG u MOIST 6: Skunk cabbage group, HG-HD

Indicator attribute: SNR u SNR=average amount of essential soil nutrients available to plants over several years u Actual SNR=based on rooting zone mineralizable nitrogen as the single differentiating characteristic u Relative SNR: relatively poorest to relatively richest u Both actual and relative SNR can be classified into five classes (VP-VR)

Substrate Indicator Groups, Coastal BC u NITR 1: Salal group, VP-P u NITR 2: One-leaved foam-flower group, M u NITR 3: Three-leaved foam-flower group, R-VR

Indicator attribute: Ground Surface Material (Substrate) u Soil surface is source of plant water and nutrients, and influences vegetation composition; u Decomposition releases nutrients, and therefore humus form is index of available nutrients

Substrate Indicator Groups, Coastal BC u GSM 1: Red huckleberry group, Mors u GSM 2: Sword fern group, Moders and Mulls u GSM 3: Pearly everlasting, mineral soil u GSM 4: Sellaginella group, very shallow and rocky soils u GSM 5: Sphagnum group, wet soils

Indicator Plants to Learn -see course website for Indicator Plant List and photos The url is:

Premise of using indicator plants in BEC u The occurrence and vigour of a plant species on a particular site reflects the quality of the site (because we know each plants’ ecological amplitude)

Indicator values u Can be integers or names that refer to classes along environmental gradients u BEC: names for SMR (VX-HD), SNR (VP-VR); convert to integers u Ellenberg (1974): Used values 1-9 for gradients of light, temperature, soil moisture, soil nitrogen, soil acidity u The indicator value for a species reflects its correlation with its environment

Best site quality indicator factors u Soil moisture regime, soil nutrient regime, climate, substrate u All affect plant physiology, yet are relatively environmentally stable