Tackling the NPMS in the field: a lowland example

By now many of you will no doubt have made at least one visit to your NPMS square – we hope you have enjoyed the challenge! Don’t forget that the first visit is the hardest one, because choosing the plots is a key initial step in the National Plant Monitoring Scheme. Subsequent visits to a square will focus on monitoring your established plots, and also hopefully on continually improving your plant ID skills!

In the rest of this blog post we provide a brief example of how one of the NPMS team went about surveying their square (as a volunteer). Don’t worry if your approach differed slightly, within the guidelines there are many different things that you could do in your square; for example, whilst we have recommended 5 plots, that can be adjusted to accommodate what is possible on the ground. Likewise, the balance between square and linear plots can be adjusted to suit the access you have in your square. This example is in the lowlands, but we hope to provide an upland example as well in the coming weeks.

Square and linear plots (in blue) chosen in a lowland square
Square and linear plots (in blue) chosen in a lowland square

In the example above, I was able to use two of the randomly chosen square plots (numbers 1 and 5 above). In one case a plot (5) fell into a churchyard – a rather closely managed sward, but a little poking around turned up Adder’s-tongue – a scarce plant in West Berkshire! My second plot (number 1 on the map) was in a piece of pasture that was moderately diverse, and that had already been picked out by the basemap as lowland grassland of potential interest. I surveyed this square at the Inventory level and ended up with 27 species, with 4 species from the ‘Neutral Meadows and Pasture’ Indicator list. Don’t forget that you can vary the level (Wildflower / Inventory / Indicator) at which you survey between plots, allowing you to record more in habitats where your ID skills might be better developed.

Adder’s-tongue in plot 5.
Adder’s-tongue in plot 5

Given that only two of my suggested square plots fell into accessible habitats, my remaining plots were all linear plots, with the locations decided by the grey gridlines (although of course extra, self-selected, square plots can also be chosen if that is the only available option). I decided to begin my plots where the feature of interest (i.e. the stream, hedgerow, arable margin etc.) intersected with the mapped gridline, as you will hopefully be able to see in the illustration. Another method might be to take the intersection as the midpoint of your plot: it doesn’t really matter, as long as you are consistent and try not to be swayed by which direction looks nicest! (Flipping a coin might help you to decide which direction to extend your linear plot in.)

My ‘Rivers and streams’ plot was not terribly interesting – only one ‘Rivers and streams’ Indicator species (Bittersweet [Solanum dulcamara]), but it will be fascinating to see whether it changes over time. Here is my sketch of the plot – not a great work of art, but with the estimated grid references, it should be enough to relocate it fairly accurately. If your sketching ability improves year-on-year, or if things change, the option to upload new sketches each year is available (but this is not essential).

Plot sketch
Sketch of Rivers and streams plot

A second linear plot led to some challenges on the habitat front – the pond was really a broadening of a brook, so I was torn between ‘Rivers and streams’ and ‘Nutrient rich lakes and ponds’; however, in the end I decided that the area I was surveying was quite a broad water body, and with only very sluggish water movement, and I so opted for ‘lakes and ponds’. My final plot was an arable margin. This only had negative indicator species, but, again, it will be very interesting to see how this changes over time.

I hope you had as much fun exploring your square as I did mine. Don’t forget, if you have ended up with a square that seems a bit short on botanical diversity, you can always adopt a second square and visit the two squares on rotation (i.e. visit square 1 this year, square 2 next year, and then revisit square 1 in year 3 and so on). This could provide more variety and give you a chance to improve your ID skills. However don’t forget that even if a plot has few or no ‘Wildflower’ or ‘Indicator’ species, this is still important and valuable information to record

Please get in touch with Hayley, the NPMS coordinator, if you have any stories about your square, or if you’d like to share your approach with us, perhaps to feature on this blog or in future newsletters.




Thank you for this example. How big should the square and linear plots be?

Kind Regards,


Plot size

Hi Becky. Square plots are 5x5m unless in woodland where it is 10x10m. The linear plots are 1mx25m. Full details can be found in the survey guidance notes on pages 9-14. Best wishes Hayley


What is it that you are calling a 'flush'? There is no mention of such a noun relating to water features on the web.

You clearly don't mean a stream or spring because you use those words separately in The Guidance Notes.

So please give us a full definition of a 'flush'.


Hi Nic, here is the definition - Flushes are areas where water from underground flows out onto the surface to create an area of saturated ground, rather than a well-defined channel. See http://freshwaterhabitats.org.uk/habitats/flush/ for further information. Best wishes, Hayley


Thanks for that definition. So since the water is oozing out from below, its source will not be visible. That water could create a STREAM [habitat5] or 'saturated ground' which could be a MARSH, MIRE, MOOR, SWAMP or FEN [habitat8] or a BOG or MOOR [habitat2]. However a MARSH, MIRE, MOOR, BOG or FEN can also be formed by water accumulating or flowing onto/into flat ground, so is the difference between them the source of the water?

Is a legitimate simplification of a 'flush' for survey purposes: where water from underground on a slope creates a bog rather than a spring ?

This would mean that the ditches in our calcareous square [some of which dry out in the summer and some not], would have their sources as either SPRINGS or FLUSHES [habitat8] near the bottom of the slope and the ditches would count as STREAMS [habitat5]