Application of Relevé Method for Vegetation Community Assessment and...

Application of Relevé Method for Vegetation Community Assessment and Management

Presented by:Frances Reese, M.S.Lu Engineers

What is a relevé?

Quadrat - typically a square or circular area of defined dimension used consistently throughout a sampling regime

Relevé - can vary based on plant community characteristics, soil conditions, slope and other factors

Relevé is a plant community sampling area

Why Select the Relevé Method?

Cost-effective - Data acquisition is rapid, field time minimizedFlexible - allows for adaptation based on field conditionsEasy to learn, no complicated equipment requiredFaster than traditional point-intercept, basal area analysis, stem count, or biomass weighing techniquesAccepted by ASTM and general ecological community.

History of Relevé

Initial concept developed by Swiss ecologist Jacques Braun-Blanquet during mid-20th c.

Useful to classify species diversity of plant cover in large areas

Method Characteristics

Semi-quantitative Relies on an visual estimate of plant coverDoes not rely on

specific number of “hits” along a transect line precise measurements of cover biomass by planimetric or weighing methods

Relevé has no set size

Characteristics of Sample Area

Compositional integrityRelevés are differentiated from adjacent stands by a discernible boundary

Structural integritySimilar history or environmental setting. Relatively similar horizontal and vertical spacing of plant species. Relevés may be differentiated on basis of soil substrate, slope, moisture regime, or elevation.

Relevé Size vs. Landscape Context

Desert landscapeLarge relevé area required due to wide spacing of plants

Prairie landscapeSmaller relevé area needed due to differing topographic, moisture and soil factors in landscape

Selecting size of sample area

Size of relevé is determined by the smallest area on which the species composition of the community is adequately represented

Alpine MeadowArctic Tundra

Desert Landscapes Forested Cover

Small (≤ 50 sq. m) Large (≥100 sq. m)

Characteristics of Relevé Sample Areas

Structural and compositional aspects of relevé are combined into homogeneous units.

Homogeneous vegetation canopyHomogeneous soil type, slope, moisture regimeLarge enough to contain all the species in the communityRecognizable as a unit that is repeated in other areas of the landscape (a repeating assemblage of plants)

What information is collected for a specific relevé?Site name and location - georeference coordinates

Community type (upland deciduous woods, emergent marsh, etc.)

Site factors (soil type, moisture regime, slope, depth to bedrock)

Cover class of species (visual estimate of % cover) within relevéarea

Sociability class (how is the species aggregated within sample area)

Optional information: Vigor and phenology of species (how well plant is growing, and what stage of growth - flowering, fruiting, senescing)

Typical Minimum Relevé Sizes

10-50Calcareous grasslands10-50Alpine meadows & dwarf shrubs10-50Heathlands10-25Hay meadows10-20Mobile coastal dune communities5-10Pastures2-10Salt marshes1-10Dune grassland1-4Hygrophylous pioneer communities1-4Terrestrial moss communities

0.1-0.4Epiphytic communities

Size (sq. m)Plant Community

Source: Westhoff V. and E. van der Maarel. 1978. The Braun-Blanquet approach. In: Whittaker, R.H. (Ed.) Classification of plant communities. Boston: Junk, pp. 617-726.

Typical Minimum Relevé Sizes

Size (sq. m)Plant Community10-100Chaparral, temperate sclerophyll

shrublands25-100Weed communities

25-100Scrub communities50-100Steppe communities 100-500Temperate deciduous forest 200-800Mixed deciduous forest 200-1000Tropical secondary rainforest2000-4000Tropical swamp forest

Source: Westhoff V. and E. van der Maarel. 1978. The Braun-Blanquet approach. In: Whittaker, R.H. (Ed.) Classification of plant communities. Boston: Junk, pp. 617-726.

% Cover Concept10 m

10 m5 m

2 m

10 m x 10 m square area = 100 sq. m

10% of area = 10 sq. m

2 m x 5 m area represents10% cover

Individual species (taxon) is said to have 10% cover if it covers 10% of the area of a relevé. In field data collection, each taxon (species) is rated with a cover class of 1-5, with 1 being 75-100% to 5 (1-5%).

Sociability Concept

Class 1 - Species occurs in large, nearly pure standClass 2 - Species occurs in large aggregates or carpetsClass 3 - Species occurs in small aggregates or clustersClass 4 - Species occurs in isolated clumps or bunchesClass 5 - Single occurrence of species in relevé

10 m 10 m 10 m

Sociability Class 5

10 m

Sociability Class 1

10 m

Sociability Class 3

10 m

Sample Relevé Data

Sheet

Two Examples of UseRochester Army Aviation Support Facility

Small area (< 10 acres) required detailed site investigation for project impact analysisSmall relevé size required due to complex moisture regimes created by development activities

Oriskany Flats Wildlife Management AreaLarge Area (100+ acres)Screening level analysisRelevé size adjusted to fit forested and open, monospecificcover types

Rochester Army Aviation Support Facility, Greater Rochester International Airport, Monroe County, New York

Project is an expansion of an existing helicopter maintenance facility, including tarmac area and hangars; will impact 0.24 acre of federal wetland

ACOE requested base line vegetation community data on wetland that may be affected by storm water discharge

Data used to assess potential impact to wetland of discharging storm water without retention from the expanded project site

How was the Relevé Method used?

142 AVIM, 1 Bn53d Troop Command

Rochester Army Aviation Support Facility Site Location Map

33 acre site, drains to 3rd order tributary of Genesee RiverCannot do on-site wetland mitigation because it is located in an airportSpace limitations constrain ability to put storm water retention facilities above ground


Schematic View of ImprovementsProposed at RAASF Site


Rochester Army Aviation Support Facility Relevé Locations

58 relevés used to cover 9.0 acre wetlandDominant species

cattailcommon reedpurple loosestrifered osier dogwoodgreen asheastern cottonwood


Relevé Information Used to Assess Impact of Increased Storm Water Discharge

Will use under-tarmac pipe storage system to retain storm water if necessaryStudy completed to see if adjacent wetland would be adversely affected by discharge of storm water without detention


Airport Concerns

Airport concerned that discharge of storm water into wetland without detention could cause increase in open water area and expansion of wetland boundary

Open water areas and wetlands are “wildlife attractants.”

FAA Advisory Circular 150/5200-33 recommends separation distance of 5,000 feet from aircraft movement or parking areas serving piston-powered aircraft for wildlife attractants.


Corps of Engineers Concerns

Loss of wetland habitat (0.24 acre)Quality of water discharging from tarmac directly into the wetlandAvoidance, minimization and mitigationAppropriate off-site mitigation required due to site’s location at airport


Study ResultsRelevé study results:

Plant community comprised of species that tolerate frequent, rapid water level fluctuationsSpecies composition of wetland is not expected to change as a result of discharge of storm water without detentionNo increase in wetland size likely

Hydrology study results:No increase in storm water retention time under 100 yr storm eventNo increase in open water areasStorm water residence time in wetland ≤ 2.1 days (not sufficient to cause change in wetland plant community)

Project status: in review with ACOE/NYSDEC


Oriskany Flats Wildlife Management Area, Oneida County, New York

774 acre wildlife refuge owned and managed by the NYS Dept. of Environmental ConservationLocated in flood plain of Mohawk RiverNear Revolutionary War era OriskanyBattlefield and Fort Stanwix

New York State Department of TransportationThomas J. Madison, Jr., Commissioner

New York State Department of Environmental ConservationDenise M. Sheehan, Commissioner


Project Overview

Site investigation completed as part of mitigation effort for bridge reconstruction project.

NYSDEC needed base line information on habitat to plan improvements at OFWMA

Wetlands at OFWMA drained for agriculture 75 years ago; planted with reed canary grass and used as pasture



AssessmentArea

First Steps in Landscape Restoration

NYSDEC consulted on needs for OFWMARelevé assessment of 100 acres done to create a base line of habitat information



Erie Canal

Mohawk River

RelevéSurveyArea

Rt. 922EBridge

ReconstructionSite

Photo source: NYSGIS, ca. 1994

How was Relevé Method Used?22 relevés used to cover 100 acres

Relevé size smaller because cover types were simple

Large monospecific reed canary grass standsCorn fieldsPatches of flood plain woods and hedgerowsOld fieldsDrainage ditches

Preliminary site walkover required



Recommendations from Relevé Study

Cover type: Reed canary grass emergent marsh

Condition: Little species diversity

Recommendation: Place water level control structure at outlet from drainage channel to increase water levels inmonospecific stands of reed canary grass




Cover type: Flood plain woods - silver maple, green ash, black willow

Condition: Flood plain woods mainly comprised of silver maple, green ash and black willow. No mast-bearing trees.

Recommendation: Plant native, flood-tolerant mast-bearing trees (swamp white oak, sycamore, beech)




Cover types: Hedgerows, drainage ditches, and spoil pilesCondition: Invasive species such as common buckthorn, European alder, and tartarianhoneysuckle reduce habitat valueRecommendation: Develop monitoring and control plan for invasive species


Cover type: Drainage ditch Condition: Erosion along edge of drainage ditches reduces water quality. Large willows and silver maples block waterways, creating pools. Pool and flooded areas show greater diversity. Recommendation: Use large woody debris to create more pools to increase diversity and restore bank stability



Continuing Activities

April, 2001 - NYSDOT, NYSDEC, USACOE, local groups form working groupUSACOE, NY District currently preparing an Ecological Restoration Plan for OFWMA2004 - Hydrology and hydraulic studies completed by USACOE2006 - Ecological Restoration Plan due

Uses of Relevé Method

Base Line Natural Resource Condition SurveysPark or Trail PlanningHabitat Restoration or Management Plans Invasive Species Surveys Climate Change Studies - long term study plotsEnvironmental Impact AssessmentsWetland and Water Quality MonitoringPermitting Studies

Cost Factors

Why are you collecting the data and how will it be used? Litigation - data defensibility and replicabilityBasic scientific researchProject planning and mitigation - need answers fast

Size and number of field teams (best to use 2 persons per field team)

Size and complexity of site to be investigated: size ofreleves, accessibility, time frame of investigation

Physical factors: topography, climate, safety issues

The Lu Engineers Experience

Be clear on your project purpose and objectivesPre-plan your field work with aerial photography and a preliminary site visit Clear all access, safety and security issues with your client and the site ownersRelevé method is good for rapid data acquisition and has fast learning curveGeneral rule of thumb: for a mixed habitat area in the northeastern U.S., allow about 2 days/100 acres/field team.

Selected References

American Society for Testing and Materials. 1997. Standard Guide for Sampling Terrestrial and Wetlands Vegetation. Standard E-1923-97 (2003). Download from http://www.astm.orgBarbour, M.G., Burk, J.H., and Pitts, W.D. 1980. Terrestrial Plant Ecology. Benjamin/Cummings Publishing Co. CNPS Vegetation Committee. October 20, 2000 (Revised 2/5/03). California Native Plant Society Relevé Protocol. Available at: http://www.cnps.org/archives/forms/releve.pdfDombois, D.M. and Ellenberg, H. 1974. Aims and Methods of Vegetation Ecology. John Wiley & Sons. Greig-Smith, P. 1964. Quantitative Plant Ecology. Butterworth & Co., Publishers. Moore, P.D. and Chapman, S.B. (eds.). 1986. Methods in Plant Ecology(2nd ed.), Blackwell Scientific Publications.

Questions?

Web Site: http://www.luengineers.com

E-mail contact:[email protected]

Application of Relevé Method for Vegetation Community Assessment and...

Documents

Transcript of Application of Relevé Method for Vegetation Community Assessment and...