Rainbow Beach Management Plan 3-11-2019.docxRainbow Beach Conservation Area – Habitat Management Plan
Chris Buelow – Restoration Ecologist – MA NHESP – 2018-March-20
Introduction:
The Massachusetts Division of Fisheries and Wildlife’s (MassWildlife) Biodiversity Initiative, in conjunction with the City of Northampton, is proposing plans to restore and maintain
the Major River Floodplain Forest natural community at the Rainbow Beach Conservation Area in Northampton, MA (Locus, Figure 01). The Rainbow Beach Conservation Area supports one of
the largest and most intact examples of Major River Floodplain Forest in Massachusetts, which is considered to be amongst the highest natural community conservation priorities for MassWildlife.
The Major River Floodplain Forest of Rainbow Beach Conservation Area also supports several highly specialized and quite rare plants and animals that are dependent upon high integrity
Floodplain Forest communities.
The burgeoning presence of invasive plant species has been identified as the primary threat to the continued function of the Major River Floodplain Forest at the Rainbow Beach Conservation
Area. A comprehensive survey of invasive species distribution, density and composition funded by MassWildlife in 2016 showed approximately 50-acres of invasive free high integrity
Major River Floodplain Forest remains at the site. The remainder of the Conservation Area is being impacted by invasive plants to various degrees, ranging from light, scattered presence,
to high density, multi-species infestations. Left uncontrolled, invasive plants at the site will continue to expand in distribution, density, and impact, resulting in the eventual
loss of the core Major River Floodplain Forest as a high integrity community, and rendering the currently impacted areas of Floodplain Forest virtually beyond restoration.
Invasive Species identified during the 2016 inventory as impacting the Conservation Area are:
Japanese knotweed, Asiatic bittersweet, winged euonymus, common buckthorn, Pachysandra, bishop’s weed, Japanese barberry, phragmites, autumn olive, reed canary grass, garlic mustard,
multi-flora rose, winter creeper, northern catalpa, and moneywort.
General Invasives Control Approach:
This plan is intended to outline the general approach expected to be used in controlling invasives species at the Rainbow Beach Conservation Area. It is intended to rely heavily upon
the principles of adaptive management: i.e., instead of laying out a specific long term sequence of specific actions, this plan will instead identify core goals of invasives control
at the site and outline the invasive plant control techniques expected to be used.
The primary Goal of this plan is to control invasive plant species at the Rainbow Beach Conservation Area in order to keep the existing high integrity Major River Flood Plain Forest
functioning at a high level, as well as to restore a high level of function to areas currently being impacted by invasive species. The eradication of invasive plants from the entire
site is not expected to be feasible: instead the primary goals of this plan are to keep new infestations from establishing in the core high integrity areas, and reducing invasive presence
in the currently impacted areas to a level that will either allow highly impacted areas to recover, or lightly impacted areas to continue functioning as Major River Floodplain Forest.
In general, a two-track approach will be taken when setting initial priorities for invasive species control in the Conservation Area. Maintaining the current high integrity area in
a state free of invasives will be an ongoing effort, and will involve annual/biennial patrols with an early detection/rapid response philosophy designed to keep new infestations from
establishing in this area. Concurrent with maintenance in the high integrity area, an initial focus will be placed upon the control of species that pose the most immediate threat to
the greater Conservation Area. Japanese knotweed has been identified as the most immediately impactful species in the Conservation Area due to its ability to spread quickly and create
monocultures, and because it’s control can require several rounds of treatments.
Longer-term, outside of the high integrity area, a more general invasive species control effort is proposed that focuses on restoring impacted units instead of targeted individual species.
Most likely, areas of low-to-moderate density invasive species presence will be targeted in broad units where multiple species can be treated at the same time using the same method.
The bulk of invasives presence at the Rainbow Beach Conservation Area are appropriate for this type of a broad control approach, and include Asiatic bittersweet, multi-flora rose,
autumn olive, common buckthorn, winged euonymus, Japanese barberry.
Some invasive species present in the Conservation Area present unique challenges for control due to either their structure (ex. northern catalpa) or their required control technique
(ex. Pachysandra, bishop’s weed). These species will likely be targeted in Conservation Area-wide control efforts focused on the individual species.
Areas of high-intensity infestation, where most ecosystem function has already been lost, will likely not be treated until later in the treatment cycle. This approach is to ensure that
higher integrity areas are treated early in the process, before invasives severely impact their function. Eventually, even the high-intensity infestations should be treated with the
goal of returning them to functioning natural communities. Exceptions to delayed treatments in high-intensity stands may arise when other conservations targets occur in high-intensity
stands, such as rare plants. In these cases, the initial treatments will most likely be focus around the conservation target, with the intention of simply maintaining the conservation
target’s presence until a larger scale treatment is scheduled.
Proposed Techniques:
In most cases chemical treatment is the only practical way to effectively control established populations of invasive plants. Fortunately, herbicide treatments are very effective, and
when properly applied, herbicide treatments are also safe and ecologically sound. MassWildlife has a long history of experience with invasive plant control projects and a demonstrated
track record of achieving clear benefits to target rare species and other wildlife while reestablishing appropriate native plant communities on the footprints of former invasive plant
infestations. In the case of this project, it is expected that the majority of invasive treatments in the Conservation Area will be accomplished through the use of foliar herbicide
applications. The primary reason for favoring foliar applications in the Conservation Area is because foliar applications allow for by far the most efficient means of treating large
scale infestations at a high level of efficacy while still obtaining a high level of control over non-target impacts.
Using Herbicide
The following proposed activities could potentially occur in wetland resource areas and buffer zones and are designed to improve habitat for wildlife, restore plant communities and ecosystem
function, and are designed to avoid changes to hydrology, soil conditions, and the buffering capacity of wetland vegetation to filter runoff and attenuate pollution.
When using herbicide on DFW related projects, the following are required of both DFW staff and contractors:
Applicators must be currently licensed Massachusetts Pesticide Applicators.
Applicators may only use herbicides and surfactants approved for use in Massachusetts, and all herbicide use must comply with labeled instructions. Only herbicides and surfactants labeled
for use in wetlands may be used in wetland resource areas.
Applicators will log activities (amount of herbicide used, locations of daily treatments, hours spent at the site, etc).
Applicators will use best application practices at all times. In particular, applicators will focus on reducing drift and non-target effects. Key aspects of this are:
Only spraying when wind speeds are below 10 mph
Selecting the most appropriate application technique for each situation; i.e.:
only using mist-blowers in dense invasive stands
using a hydraulic back-pack sprayer on smaller invasive patches
using the most discrete application methods around rare plants
There are several ways that herbicide is applied when treating invasive plants, including mist-blower, hydraulic backpack-sprayer, wick, glove and cut-stem. Each method or combination
is appropriate for specific situations:
Mist-blower: A mist-blower is a motorized applicator that forces a stream of herbicide through a blast of air that atomizes the herbicide into fine droplets. Typical mist-blowers resemble
(and function somewhat like) back-pack style leaf-blowers. The primary advantage of mist-blowers is that a large area can be treated in a short amount of time while using less herbicide
than more conventional applications. Mist-blowers are often used in large, dense patches of target vegetation. Mist-blowers are important tools in treating large areas, and when used
by experienced applicators, drift to non-target plants is minimal.
Hydraulic Backpack-Sprayer: A hydraulic backpack sprayer is a non-motorized pump worn on the back of an applicator. The applicator uses a hand-lever attached to the tank that keeps
the tank pressurized, forcing a spray of herbicide through a nozzle on demand. Hydraulic backpack sprayers are capable of treating much less area than a mist-blower while using a higher
volume of herbicide. The advantage of a hydraulic back-pack sprayer is greater control of herbicide drift. The primary use of a hydraulic back-pack sprayer is for spot-treatments.
Wick: Wicks come in many forms, but they are essentially a rope wick attached to a reservoir of herbicide. When in operation, the wick becomes saturated with herbicide and is then wiped
on the target vegetation. Two of the more common types of wicks used are a weed-wand and a boom. A weed-wand is essentially a wick at the end of a handle; the applicator stands and
wipes the wick against the vegetation. A boom is a long wick mounted on a horizontal bar and moved over the vegetation as a desired height. This can be done either by mounting the
boom to a tractor, or by tying a rope to each end of the bar and dragging the boom through the vegetation. The advantage of the wick is the ability to very precisely treat an area
while minimizing herbicide volumes.
Glove: The glove technique is essentially a variation of a weed-wand, but the wick is a glove worn on the hand. The applicator simply wears a wooly glove with a protective rubber
glove beneath, dips the gloved hand into herbicide until it is saturated, and then wipes their gloved hand against the target vegetation. This method is typically used in sensitive
areas.
Cut-stem: The cut-stem technique consists of an applicator cutting stalks/stems and dripping herbicide into/onto the hollow stem/cut stump of the plant. Cut-stem treatments are the
most precise of all listed treatments, but are also by far the most labor/time intensive.
Pulling
Pulling invasives can occasionally be an effective technique used in invasive plant control, particularly in situations of low density infestations of shallow-rooted species. There
are three primary pulling techniques: Hand-Pulling, chaining or cabling, and Weed-Wrenching. Hand-pulling is a technique used to opportunistically remove small, isolated invasive plant
targets, or certain shallow-rooted herbaceous targets. Soil disturbance resulting from hand-pulling is usually minimal. Chaining involves wrapping a plant with a chain or cable attached
to a vehicle and tearing the plant from the ground. Resulting soil disturbance is moderate, usually impacting an area immediately around the stump and primary root trail. A Weed-Wrench
is a hand tool that uses leverage to pry woody vegetation up to 4”dbh from the ground. Resulting soil disturbance is moderate, usually impacting an area immediately around the stump
and primary root trail. Only hand-pulling is anticipated in the Rainbow Beach Conservation Area.
Flame-Weeding
Flame-weeding employs a propane torch to apply heat/flame to the targeted plant. Targets are typically unwanted woody vegetation (heat applied to boil cambium), or unwanted cool season
grasses (heat applied to the base of culm). Flame weeding is either used under conditions of low ignition probability (cold or wet) or with the presence of supporting staff with appropriate
suppression equipment (water pump and/or hand tools). Flame -Weeding is currently not anticipated in the Rainbow Beach Conservation Area.
Biological-Control
For this document, the term Biological-Control refers to biological agents that are introduced to control another species that is considered to be noxious; typically a non-native, invasive
species. Bio-control agents are highly regulated and are not approved for release unless they have been proven to exhibit strict host specificity. All Biological-control agents require
USDA-APHIS approval, as well as permits from the State of Massachusetts. Currently, Biological-control agents are not commonly used by MassWildlife, though it is possible that a situation
may arise in the future where a Biological-control agent may be considered for use in the Rainbow Beach Conservation Area..
Invasive Treatment Site Preparation
In some cases it is advisable to cut vegetation before herbicide treatment. This is usually done to A) lower target biomass to a reachable level to focus application of herbicide; B)
weaken the target plant so that it will be more susceptible to the herbicide treatment; C) remove dead individuals in order to ensure that the maximum amount of herbicide reaches the
target plant; and/or D) remove above ground non-target vegetation from a target invasive plant area to further reduce the chance of non-target effects. Cutting typically is done with
a chainsaw, brushsaw, or walk-behind mower. In most cases, cut material is left behind unless it contains a large amount of seed or is a species capable of vegetative reproduction.
An important use of cutting at the Rainbow Beach Conservation Area involved the cutting of Japanese knotweed stands several months prior to an herbicide treatment to increase the efficacy
of control.
Figure 01: Rainbow Beach Conservation Area Locus
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