Tree Lake Association.

It’s too nice, not to care!

Management Recommendations

1. Become involved in the Self-Help Volunteer Lake Monitoring Program again, monitoring water clarity.

2. Chemical treatments for plant growth are not recommended in Tree Lake due to the undesirable side effects of chemical treatments. 

· The decaying plant material dies in place, enriching the sediments, encouraging more plant growth.

· The decay releases nutrients that feed algae growth that reduce water clarity. 

· Broad-spectrum treatments would open up areas that would be vulnerable to the introduction of the exotic species. 

· Copper compounds used to treat algae will build up in the sediment, resulting in toxic sediments. 

· Plant growth appears to have actually increased during the time period that chemical treatments occurred.   The shift from dominant plant species in 1978 and 1997 that are disturbance tolerant to a dominant species dependent of clear water may signal a recovery from past herbicide treatments. 

1. Restore natural shoreline.  Disturbed shoreline covers nearly half of the shore; mowed lawn alone covers more than one-quarter of the shore.  Un-mowed native vegetation reduces shoreline erosion and run-off into the lake and filters the run-off that does enter the lake. Shoreline restoration could be a as simple as leaving a band of natural vegetation around the shore by discontinuing mowing or as ambitious as planting native grasses, flowers, shrubs and trees on the shore and native wetland vegetation in the shallow water zone off shore.

2. Protect emergent plant beds for habitat and to stabilize the shore and prevent erosion.

3. Reduce nutrient input to the lake.  Tree Lake is near the entropic range and small increases in nutrients could result in much greater plant and algae growth. A University of Wisconsin-Stevens Point (Turyk 2004) study suggested that nutrients from lawn fertilizers and septic systems were entering the lake through the groundwater.

· Restoring natural shoreline and protecting emergent plant beds will also help reduce nutrient input to the lake by reducing erosion and sediment that carry nutrients and by slowing and absorbing nutrients in run-off.

· Eliminate all lawn fertilizer use, organic or inorganic.

· Check and maintain septic systems.

· Devise a harvesting plan that will among other things, remove nutrients contained in the plant biomass. 

1. Harvesting can remove significant plant biomass and its nutrients and can be used to control species that are invasive or that have become overabundant.  The harvesting plan should focus on removing nutrients, providing navigation, targeting nuisance species, preventing the spread of species that are encouraged by harvesting and improving habitat (Figure 16).

· Removing nutrients.  The 1.5-5ft depth zone has the greatest density of plant growth.  Harvesting in the 3-5ft zone would more effectively remove nutrients.  This is also the zone with the highest density of Chara spp., which has been dominant in some years and is currently exhibiting a habit of dense growth.  Chara can be scooped out as the harvester cuts in this zone and filamentous algae can be skimmed and removed before it decays and releases nutrients.

· Providing navigation.  Cutting vegetation in the 3-5ft zone will provide a ring around the lake for navigation.  In addition, where the ends of docks are shallower than 3 feet or deeper than 5 feet, additional channels can be added at the end of the docks that join with the 3-5ft zone.  Channels cut into the docks can be added where needed.

· Controlling invasive species.  No exotic species exist currently in Tree Lake.  Harvest minimally at the boat ramp, one channel the width of an average boat.  The public access is the site at which new invasions generally start.  By not disturbing the plant bed at this site, harvesting will not open up an area for exotic species to colonize.

· Nuisance species.  Ceratophyllum demersum is not yet a nuisance condition, but has increased lake-wide more than the other species.  This species is not rooted and can be skimmed as the cutter cuts channels and harvests the 3-5ft zone.  The 10-20ft depth zone can be cut as necessary.  This is the most appropriate zone for higher speed boat traffic and is colonized only by C. demersum and Najas flexilis (a low-growing plant). Cleaning the C. demersum from this zone will reduce obstructions to recreation and help reduce C. demersum in Tree Lake.

· Prevent spread of abundant species.  Avoid harvesting in the 5-10ft depth zone, only cutting where a channel from a boat dock needs to be extended to the >10ft zone.  This is the zone with the greatest species diversity and should be left undisturbed.  Vallisneria americana is dominant in this zone and harvesting this species encourages its growth. 

· Improve habitat.  The colonization of plants in Tree Lake is currently higher than ideal for quality fish habitat.  But cutting the channels and areas indicated above, areas would be opened for wildlife use and as cruising lanes to facilitate hunting by predator fish.  This will encourage a more balanced fishery.