New Jersey Field Office
Northeast Region
 

Knieskern's Beaked-rush (Rhynchospora knieskernii) [threatened]

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Guidance

Additional Information

 

IN BRIEF

Habitat:
Early successional (open, sparse) wetlands

Main Threats:
Habitat loss
Disturbance
Succession

Fun Fact:
Knieskern's beaked-rush is only found in New Jersey.


Overview

Knieskern’s beaked-rush was federally listed as a threatened species in 1991.

A semi-perennial member of the sedge family, Knieskern’s beaked-rush is a grass-like plant that grows 0.6 to 24 inches tall and is distinguished from other species by its fruit (achene). Fruiting typically occurs from July to September.

Knieskern’s beaked-rush is found only in (endemic to) New Jersey. An obligate wetland species, Knieskern’s beaked-rush occurs in early successional wetland habitats, often on bog-iron substrates adjacent to slow-moving streams in the Pinelands region. In the past, fire may have played an important role in creating and maintaining suitable habitat for Knieskern’s beaked-rush. This species is also found in human-disturbed wet areas that exhibit similar early successional stages due to water fluctuation or periodic disturbance from vehicles, mowing, or fire. These human-influenced habitats include abandoned borrow pits, clay pits, ditches, rights-of-way, and unimproved roads. Knieskern’s beaked-rush is often associated with other sedge and grass species. However, it is intolerant of shade and competition, especially from woody species, and is sometimes found on relatively bare substrates.

Threats to Knieskern’s beaked-rush include habitat loss from development, agriculture, hydrologic modification, and other wetland alterations; excessive disturbance from vehicle-use, trash dumping, and other activities; and natural vegetative succession of the open, sparsely-vegetated substrate preferred by this species.

Distribution of Knieskern's Beaked-rush in New Jersey by municipality
Map of distribution of Knieskern's Beaked-rush in New Jersey by municipality

Distribution

Species Range: Knieskern's beaked-rush occurs in New Jersey. The species may have historically occurred in Delaware, but records are questionable.

Distribution in New Jersey: Knieskern's beaked-rush occurs in Monmouth, Ocean, Burlington, Camden, and Atlantic Counties.

Examples of actions that may affect this species

The following is provided as technical assistance only and is not intended as a comprehensive list of all activities that may affect this species.

Within wetlands supporting Knieskern’s beaked-rush:

  • any activity, especially
    • vegetation removal
    • wetland flooding, filling, draining, ditching, tiling, or excavating, including activities that may puncture a clay layer leading to incidental draining of a perched wetland
    • stream channelization, diversion, stabilization or impoundment
    • discharge of storm or waste water
    • application of herbicides, pesticides or fertilizers
    • changes to current management practices that may lead to vegetation succession
    • operation of motor vehicles
    • planting of woody or herbaceous vegetation

Within 500 feet of wetlands supporting Knieskern’s beaked-rush:

  • any ground or vegetation disturbances, especially
    • construction or development (e.g., residential or commercial structures, sewers, utilities, roads, parking lots, driveways, and other structures or impervious surfaces)
    • stream channelization, diversion, stabilization or impoundment
    • storm water or sediment control facilities (e.g., basins, manufactured treatment devises)
    • discharge of storm or waste water
    • application of herbicides, pesticides or fertilizers
  • permanent or temporary increases in disturbance or human activity including but not limited to installation of new public access facilities (e.g., parking lots, trails)

In, or within 150 feet of, waterbodies with hydrologic connection to wetlands supporting Knieskern’s beaked-rush:

  • any ground or vegetation disturbances, especially
    • impervious surface
    • sediment-generating activities
    • storm water control facilities
    • storm water or waste water discharges (ground or surface)
    • water withdrawals (ground or surface)
    • water control structures

Best Management Practices

The following Best Management Practices are examples of typical Conservation Measures frequently recommended by the New Jersey Field Office in the course of consultation or technical assistance.

  • Avoid direct modifications to wetlands supporting Knieskern’s beaked-rush (e.g., clearing, flooding, filling, draining, ditching, tiling, excavating), and to waterbodies with hydrologic connection to Knieskern’s beaked-rush habitat (e.g., channelizing, diverting, stabilizing, impounding).

  • Provide adequate upland buffers around wetlands supporting Knieskern’s beaked-rush, often at least 300 feet of native vegetation. A site-specific buffer design is often necessary.

  • Provide at least 150-foot buffers of native vegetation along waterbodies with hydrologic connection to wetlands supporting Knieskern’s beaked-rush.

  • Implement Low Impact Design Techniques in the New Jersey Stormwater Best Management Practices Manual.

  • Avoid reforestation or landscaping within 150 feet that would increase shading of Knieskern’s beaked-rush habitat.

  • Avoid planting of native vegetative competitors within 150 feet of Knieskern’s habitat. Where possible (e.g., where erosion is not a concern), allow natural re-vegetation of bare mineral wet soils within 300 feet of Knieskern’s sites.

  • Avoid temporary impacts to wetlands supporting Knieskern’s beaked-rush, for example through

    • locating temporary work areas and access routes outside of wetlands;
    • constructing storm water management infrastructure prior to all other components of a development project to control storm water and sediment during the remaining construction;
    • installing two rows of silt fencing around work areas, with daily inspection and maintenance;
    • using jute matting or other erosion control blankets on disturbed areas immediately after project completion to minimize sedimentation; and
    • controlling invasive vegetation following temporary disturbance.
  • Avoid introductions of invasive species to wetlands supporting Knieskern’s beaked-rush , for example through

    • thoroughly washing construction equipment offsite before use within 500 feet of Knieskern’s beaked-rush habitat; and
    • using only native plant species and weed-free mulches and soils for landscaping within 500 feet of Knieskern’s beaked-rush habitat.
  • Avoid public access or other human activities in and around wetlands supporting Knieskern’s beaked-rush.

  • Place wetlands supporting Knieskern’s beaked-rush and associated upland buffers in permanent conservation ownership or easement.

  • Work with the Service to design and implement a management plan that will maintain early successional vegetative conditions.

What to do if this species occurs on your property or project site

  • Contact the Service early in planning for any project or activity that may affect Knieskern's beaked-rush or its habitat. See New Jersey Field Office Procedures for Consultation and Technical Assistance for instructions. Through the technical assistance or consultation processes of the Endangered Species Act, the Service will provide project-specific recommendations to avoid or minimize adverse effects to listed species.

  • Individual landowners with suitable habitat can also contact the Service for site-specific, proactive conservation recommendations. Most land in New Jersey is privately owned. Voluntary conservation efforts by New Jersey's residents are critical in the conservation and recovery of threatened and endangered species.

  • Also see "Endangered Species and You" Frequently Asked Questions.


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Last updated: January 28, 2014
New Jersey Field Office
Northeast Region Ecological Services
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