Point-intercept aquatic plant sampling

Ray Valley, Cindy Tomcko, Donna Dustin

19 November 2008

Development of plant indicators that reflect status of plant community and habitat

Understanding factors contributing to curly-leaf pondweed dominance in lakes.

Short-term variability of plant indicators in a range of lakes

Development and publication of a point-intercept protocol.• Suggested sample effort• Indicators to monitor, ways of

analyzing• Recommended frequency of

assessment

Objectives

Highlights from 2008Highlights from 2008

Completing surveys on all sentinel Completing surveys on all sentinel lakes were a collective effort of lakes were a collective effort of Area and Regional Fisheries, Area and Regional Fisheries, Research, SWCD’s, SNF.Research, SWCD’s, SNF.

P-I surveys took a fair amount of P-I surveys took a fair amount of time on the large sentinel lakestime on the large sentinel lakes

Help in 2009 - Master Help in 2009 - Master Naturalist ProgramNaturalist Program

Cooperative U of MN extension & DNR volunteer Cooperative U of MN extension & DNR volunteer program that teaches adults about Minnesota`s program that teaches adults about Minnesota`s natural resources- empowers them to educate others natural resources- empowers them to educate others and provides opportunities to do conservation and provides opportunities to do conservation projectsprojects

Mission: to promote awareness- understanding- and Mission: to promote awareness- understanding- and stewardship of Minnesota`s natural environment by stewardship of Minnesota`s natural environment by developing a corps of well-informed citizens developing a corps of well-informed citizens dedicated to conservation education and service dedicated to conservation education and service within their communitieswithin their communities

Cooperation with Master Cooperation with Master Naturalist programNaturalist program

1-2 volunteers to help on Aq. plant 1-2 volunteers to help on Aq. plant surveyssurveys

1 DNR or SNF Crew leader1 DNR or SNF Crew leader I forward interest to crew leader, I forward interest to crew leader,

crew leader coordinates logisticscrew leader coordinates logistics Program coord. believes interest Program coord. believes interest

will be highwill be high

Recommended changes in Recommended changes in 20092009 Continue sampling 0.7 pt/acre grid with minor Continue sampling 0.7 pt/acre grid with minor

tweaks to some lakes (Elk, Cedar, Carlos) to more tweaks to some lakes (Elk, Cedar, Carlos) to more representatively sample steep slopesrepresentatively sample steep slopes

Avoid throwing rake over waste lands.Avoid throwing rake over waste lands.• Verify plant absence occasionallyVerify plant absence occasionally• Record depth at sample point, move to next pointRecord depth at sample point, move to next point

Measuring maximum depth of plants (optional)Measuring maximum depth of plants (optional)• Travel perpendicular to shore from one VP to VPTravel perpendicular to shore from one VP to VP• Capture waypoint and depth at edge of plantsCapture waypoint and depth at edge of plants• Save waypoints to shapefile, forward to GIS shopSave waypoints to shapefile, forward to GIS shop• Topic and justification discussed further on SLICE blogTopic and justification discussed further on SLICE blog

What to look at for final What to look at for final protocolprotocol

Best allocation of sampling effortBest allocation of sampling effort• Effort required to robustly yet quickly assess Effort required to robustly yet quickly assess

“status” or biotic integrity“status” or biotic integrity

• Stratify effort by depth?Stratify effort by depth? 0 – 5 ft zone – most diverse and vulnerable to 0 – 5 ft zone – most diverse and vulnerable to

nearshore disturbancenearshore disturbance Focus only on areas with substrate supporting veg Focus only on areas with substrate supporting veg

growth?growth?

• Issue: should baseline surveys follow this same Issue: should baseline surveys follow this same protocol or be more comprehensive to delineate protocol or be more comprehensive to delineate areas of veg growth and species list?areas of veg growth and species list?

AnalysisAnalysis Many discussion topics on how to analyze Many discussion topics on how to analyze

data posted to BaseCamp feedback is data posted to BaseCamp feedback is encouragedencouraged

i.e., Over what depth do we calculate i.e., Over what depth do we calculate percent frequency?percent frequency?• Constant number (15 ft) – current methodConstant number (15 ft) – current method• Compute over depth ranges?Compute over depth ranges?• Geostatistics (kriging) the best but most Geostatistics (kriging) the best but most

complex waycomplex way• Addresses issues comparing results within/among Addresses issues comparing results within/among

lakes with differing sample intensity.lakes with differing sample intensity.• Evaluates patterns of areal coverEvaluates patterns of areal cover• Addresses thorny issues of spatial autocorrelation of Addresses thorny issues of spatial autocorrelation of

neighboring survey points.neighboring survey points.

Geostatistics - ExamplesGeostatistics - Examples

CLP - KrigingPearl Survey Points

Acoustic Biovolume Point-intercept CLP