Here is the states position on Tree Cutting. I would be very careful what and how you do things around the waters edge.. Many folks looking around for people that are not following the rules. The 6" tree next to house can be removed without any issues. Please read below and review the link for clarification of policies on Shoreline Protection.
http://www.des.state.nh.us/cspa/
Can I cut trees or remove stumps and vegetation within the protected shoreland?
The protected shoreland extends from the reference line landward 250'. Within the protected shoreland is a natural woodland buffer. The “natural woodland buffer” extends 150' landward from the reference line. There are restrictions on vegetation removal in the natural woodland buffer. The restrictions per RSA 483-B:9 are:
Not more than a maximum of 50% of the basal area of trees, and a maximum of 50% of the total number of saplings shall be removed for any purpose in a 20-year period. A healthy well distributed stand of trees, saplings, shrubs, ground cover, and their living, undamaged root systems shall be left in place.
Stumps and their root systems that are located within 50' of the reference line, shall be left intact in the ground, unless specifically approved by the department, pursuant to RSA 482-A.
Structures within the natural woodland buffer are afforded openings for building construction that are excluded when computing the percentage limitations listed above.
The openings for building construction are:
For primary structures constructed behind the primary building line, the construction envelope shall not exceed 25' from the exterior edge of the footprint of the structure.
For primary structures that fall partially within or entirely within the primary building line, the envelope shall not exceed 15'.
For accessory structures, or water-dependent structures, the construction envelope is 10' from the exterior edge of the structure.
This means vegetation can be removed but only up to the limits specified above in #1 and #2 and within the building envelopes. The understory of shrubs and herbaceous ground cover may not be removed in any amount outside of the building envelopes.
Vegetation is a key component in preserving the ecological integrity of the shoreland. The canopy created by trees, shrubs and herbaceous vegetation, moderates the impact of heavy rains, shades the shoreline thereby reducing water temperature, and produces organic matter and woody debris essential to shoreland ecology. Root systems help give soil structure, help hold soil in place, direct rainfall down into the soil instead of over the soil, and can extract nutrients and some contaminates from the soil. Vegetation is also critical element of wildlife habitat. For these reasons, DES strongly recommends that landowners leave as much vegetation in place as possible.
Vegetation removal from areas outside a building construction envelope should be done very carefully and extra care must be taken to ensure a healthy well distributed stand of all vegetative layers remain. It is a violation of the law punishable by fines to exceed the limits and prohibitions of the natural woodland buffer.
What is basal area?
Basal area (BA) is the area of the tree taken at a height of 4½ feet from the ground. Basal area is expressed in square feet. (To visualize this, imagine cutting the tree at 4½ feet. The cross section of the top of the stump, would be the basal area.). BA measurements are taken from a point on the tree 4½ feet from the ground (this is commonly referred to as diameter at breast height or “DBH.” If your tree is on a slope, take the measurement from the high side of the slope.
Measurements are made with calipers or diameter tapes, or simple measuring tapes.
Using a standard measuring tape:
Determine the Circumference (“C”) of the tree at 4½ feet from the ground.
Calculate: BA = C x C x 0 .07958. For example, a tree having a circumference of 36 inches has a BA of 36”x 36” x 0.07958 = 103”2. To express this in feet, divide by 144. (103”/144 = 0.716 sq. ft.).
Using a diameter tape or calipers (where “d” is the diameter in inches):
BAfeet = d x d x 0.005454
For example, where the diameter is 10 inches, then 10” x 10” x 0.005454 = .54 sq. ft.