The ecology of Najas flexilis (Slender naiad)

NatureScot

Description

Records from a survey and autoecological study of Najas flexilis (Slender naiad) and associated waterplants from Scotland (Mainland Scotland records only). </br>

This dataset contains zero abundance records for N. flexilis. These were collected as part of a structured survey using the methodology described below

Geographic Description

Scotland

Purpose

Najas flexilis (Willd.) Rostk. & Schmidt is a submerged rooted macrophyte occurring in lakes. It is a Red Data Book species and is listed in Annexes II and IV of the EC Habitats Directive 92/43/EEC. It is also protected under domestic legislation, being listed in Schedule 8 of The Wildlife and Countryside Act, 1981, and Schedule 4 of The Conservation (Natural Habitats & c.) Regulations, 1994. In order to protect this species information is required on the ecological tolerances of the plant and the main threats to the species need to be elucidated. In addition, effective monitoring strategies are required to identify when and where the plant is endangered. The Biodiversity Action Plan for this species suggests reintroduction of N. flexilis to sites where the species has become extinct in recent years. If this is to occur information is required on when to reintroduce the plant, in what form (seed or plant) and from where. This study attempts to address some of these gaps in our knowledge of the ecology of N. flexilis.

Data quality

High: Survey was carried out by an experienced contractor, using approved methodology.

Methods

42 lakes from which N. flexilis had been recorded were investigated in Scotland. At each site N. flexilis presence or absence was recorded. The location of N. flexilis populations was determined within a loch from past records, where available, especially the Scottish Loch Survey data and the results of previous surveys for the plant. Three basic survey methods were used to locate N. flexilis within the lake; boat, shoreline and snorkel surveys. Snorkel surveys were considered the most effective for finding N. flexilis, and were adopted as the standard approach wherever feasible. Boats were used when the lakes were particularly large and there was no knowledge of exactly where the plant could be found; this enabled a larger area to be surveyed. When boats were not available, a shoreline search was carried out. Shoreline search included searching the drift, wading into the water as far as safety would allow, and throwing grapnels into the deeper water.

Citation

No citation information available.

Rights

OGL

Digitised records