Classification of Lentic Riparian Areas: Challenges and Opportunities

Linda Vance Montana Natural Heritage Program University of Montana

SRM Lentic Symposium Billings, MT February 9,2011 Goals of the presentation

 Introduce the concept of wetland classification and its benefits

 Discuss the various classification systems in effect and under development

 Evaluate strengths and weaknesses of major systems

 Assess potential for crosswalking across systems Lentic vs. Lotic Wetlands

Lentic riparian wetlands:  are associated with still water systems.  occur in basins, on slopes or on flats  lack a defined channel and floodplain.

Lotic riparian wetlands  are associated with running water systems  contain a defined channel and floodplain.  have am open-conduit channel carrying flowing water and dissolved and suspended material. We’re done, right?

 No: defining wetlands is not the same as classifying them.

 Why classify?

 Inventory and mapping

 Assessment

 Monitoring

 Management Inventory and mapping

 Classifying wetlands into discrete types allows us to track change over time, and to identify trends that may only affect specific types of wetlands

 Example: USFWS Status and Trends measures changes in acreage by wetland class Assessment

 Wetlands are typically assessed in relation to a “reference standard” representing minimally disturbed, least disturbed, or best available condition.

 Requires ability to distinguish between attributes that result from different geographic or environmental drivers or those that have been brought about by human disturbance Monitoring

 By classifying wetlands into similar types, it is easier to track the impacts of environmental variables such as drought or to predict return intervals for processes like fire

 Classification also helps predict transitions, expected restoration pathways, and community composition, so that natural change over time can be distinguished from anthropogenic change Management

 Classifying wetlands into discrete types helps managers by identifying specific responses to management actions, susceptibility to invasives, sensitivity to disturbance, etc. Great idea, let’s do it….

 Multiple classification systems already in effect and in development across the country

 Three main kinds of classification:

 Structurally-based, generally not regionally specific

 Structure and geography- based, emphasizing regional groupings

 Geography-based with strict boundaries Classification based on structure: Cowardin

 Cowardin classification is best  Landform: Palustrine, known Lacustrine, Riverine

 Designed to facilitate mapping  Vegetation/Habitat: Forested, emergent, shrub-scrub, aquatic bed  Directed at waterfowl management efforts: describes water and food availability  Water regime: Seasonally flooded, permanently flooded, saturated, etc  Widely used as a result of National Wetlands Inventory  Hydrogeomorphic modifiers: Excavated, ditched, diked,  Consistent across the country impounded PALUSTRINE AQUATIC BED PERMANENTLY FLOODED PALUSTRINE EMERGENT SEMI-PERMANENTLY FLOODED PALUSTRINE SHRUB-SCRUB SEASONALLY FLOODED

Fact that this is in the Middle Rockies is irrelevant for classification purposes Classification based on structure: HGM

 Hydrogeomorphic method is used  Geomorphic: lacustrine fringe, by the ACOE and many state tidal fringe, slope, mineral flats, transportation and water quality organic flats, depressional, agencies riverine

 The HGM emphasizes the  Water source: precipitation, functions that particular classes of groundwater, surface flow wetlands provide, e.g., flood attentuation, ground water  Hydrodynamics: direction and recharge, sediment capture, strength of flow nutrient cycling, steam flow maintenance, aquatic habitat, etc.

 It is especially useful in permitting and mitigation contexts GEOMORPHOLOGY: DEPRESSIONAL WATER SOURCE: SURFACE HYDRODYNAMICS: THROUGHFLOW

Regional handbooks have been developed to provide further guidance to classification, e.g., for prairie potholes, wet pine flats in the Atlantic coast, rainwater basin depressional wetlands in Nebraska…..but again, emphasis on geomorphology rather than vegetation Classification based on structure and geography: GAP/Landfire

 Recurring groups of biological  Level 1: Lifeform (Forest, communities in similar physical Grassland, Sparse and Barren) environments that are influenced by similar dynamic  Level 2: Climatic and ecological processes, like fire elevational gradients (e.g., or flooding alpine grassland, montane  551 ecological systems and 39 grassland) land use classes at the national level  Level 3: Geographic gradients,  Designed for use with e.g., “Northern Rocky predictive distribution models Mountain Conifer Swamp” but of wildlife species and for “Intermountain Basin predicting fire intervals and Greasewood Flat”” severity NORTH AMERICAN ARID WEST EMERGENT MARSH

Ecological systems are linked to the National Vegetation Classification Standard, and detailed information on dynamics, structure, composition and (in some cases) restoration and management is available through Natureserve and Heritage programs Classification based on structure and geography: The National Vegetation Classification Standard

 There are 8 classification levels based on 5 criteria: Level 1 Formation Class  Diagnostic growth forms Level 2 Formation Subclass  Dominant growth forms  Compositional similarity Level 3 Formation  Diagnostic species  Dominant species Level 4 Division  Biogeographic criteria enter at Level 5 Macrogroup Level 4, e.g., Level 6 Group  Division: North American wet Meadow, Riparian and Marsh  Macrogroup: Great Plains Freshwater Wet Meadow, Level 7 Association Riparian and Marsh  Group: Great Plains Prairie Level 8 Alliance Pothole Classification based on defined biogeographic boundaries: Ecological sites

 Interagency effort to define common units for inventory, monitoring and analysis

 Depends on defined biogeographic boundaries established through expert knowledge or analysis (MLRAs, LTAs)

 Includes climate features, soil features, ecological dynamics; includes state & transition models, and wildlife habitat elements and vegetation Ecological s

ECOLOGICAL SITE CHARACTERISTICS ECOLOGICAL SITE CHARACTERISTICS Site Type: Rangeland Site Type: Rangeland

Site Name: Draft Wet Meadow (WM) RRUSite 46- CName: 15-19" p.z.Draft Wet Meadow (WM) RRU 46- / / Carex rostrata - Carex aquatilis var. aquatilisC 15-19" p.z. ( / / beaked sedge - water sedge)

Site ID: R046XC518MT (Carex rostrata - Carex aquatilis var. aquatilis

Major Land Resource Area: 046-Northern( beaked Rocky Mountain sedge Foothills - water sedge)

Site ID: R046XC518MT

Major Land Resource Area: 046-Northern Rocky Mountain Foothills Strengths and weaknesses

MAPPING INVENTORY ASSESSMENT MONITORING MANAGEMENT

NWI Strong Strong Weak Weak Weak

HGM Strong-weak Strong * Strong Moderate Moderate

LF/GAP Strong Depends Moderate** Strong Moderate-weak

NVC Depends Depends Depends Depends Depends

ESD Weak Depends Strong Strong Strong Crosswalks allow for effective information mining

Palustrine Aquatic bed/ Palustrine emergent, semi-permanently flooded

Depressional, surface water through-flow

Arid West Emergent Marsh

Typha latifolia western herbaceous vegetation

No ESD (not rangeland) Take home messages

 Classification systems are vexing, but classification is vital to many monitoring and management activities

 Range professionals with an interest in wetlands need to familiarize themselves with the classification systems and their uses

MORE INFO: www.mtnhp.org