Dr M’s MalHam diary #3

eXtreme botany heads North to Malham Tarn Field Studies Centre with Dr M and University of Reading Plant Diversity MSc students, this is #3 of Dr M’s MalHam Diary.

Day 3 Monday: which was a day of species-rich vegetation in calcicolous grassland and calcicolous fun in the Ha Ha Fen!

The group walked from the FSC centre down the hill to the calcicolous grassland overlooking Malham Tarn looking at its absolutely fabulous best in glorious sunshine

Dr M and students stopped and set up a 2m x 2m quadrat and while students checked the quadrat  under the guidance of Guest Tutor Hermione, Dr M headed off to locate a second quadrat in the calcicolous mire of Ha Fen.

The grassland contains a number of calcicolous indicators (i.e. species found in chalk or other limestone grasslands):

Galium sterneri (Limestone Bedstraw)
Helictotrichon pratensis (Meadow Oat-grass)
Linum catharticum (Fairy Flax)
Sanguisorba minor (Salad Burnet)
Sesleria caerulea (Blue Moor-grass)

At MalHam and in similar locations, the high annual rainfall reduces the effect of limestone on the soil through the process of leaching, as a result, soil pH can be reduced locally,  allowing some acid indicators to coexist with the calcicoles, a situation which we don’t find so marked in southern England:

Anthoxanthum odoratum (Sweet Vernal-grass)
Danthonia decumbens (Heath-grass)
Potentilla erecta (Tormentil)

Focus on Student ID of Poaceae:

Amongst the monocots, students identified three sedges:

Carex flacca (Glaucous Sedge)
Carex panicea (Carnation Sedge)
Carex caryophyllea (Spring-sedge)

And the following grasses:

Briza media (Quaking-grass)
Anthoxanthum odoratum (Sweet Vernal-grass)
Festuca ovina (Sheep’s-fescue)

Students had located but hadn’t managed to ID two of the grasses by the time Dr M returned:

Danthonia decumbens (Heath-grass). ID hints: Ligule a fringe of hairs and whiskers on the collar, leaves glaucous above and bright yellow green below, inflorescence a small panicle with few large (“chunky”) spikelets.

Koeleria macrantha (Crested Hair-grass). ID hints: leaf blade ribbed, with three deep ribs each side of midrib, densely softly hairy, inflorescence silvery, compact panicle.

More tricky grasses to find:

Sesleria caerulea (Blue Moor-grass). ID hints: Leaves flat and hairless, glaucous and pruinose (often sparingly so), with tramlines, sheath closed below, ligule ciliate, shoots flattened with lots of dead sheath at bases. Inflorescence ovoid and dead / over in the summer! A key indicator species of northern calcicolous (limestone grassland). 

Helictotrichon pratensis (Meadow Oat-grass). ID hints: Open sheath below, leaves glaucus, narrow and wiry, often twisted or slightly spiralling, leaf blade with parallel rows of tiny white dots (stomata) above and sparingly below, tramlines and boat-shaped (hooded) tip, so like Poa but not! Inflorescence branched Panicle with large spikelets, lemmas with conspicuous dorsal awn (hence Tribe Avenea).

Dr M’s Poaceous lesson of the day: how not to miss important grasses in your quadrat. A family of grasses green and wonderful, so keep your eyes open for different shades of green as different shade = different species (probably!). Look all through the vegetation at all different levels – top, middle and bottom and look for different colours, textures, shapes and leaf angles (e.g. inclined or erect or flat to ground), look in different areas, e.g. Sesleria caerulea (Blue Moor-grass) is often found growing around rocky outcrops.

David Streeter approached when we were half way through the quadrat and we took a short digressionary diversion into the adjacent Ha Mire for an impromptu bryophyte masterclass in which David Streeter introduced us to the bryophytes growing there with a fist full of brown mosses including:

Calliergonella cuspidatum
Campylium stellatum
Cinclidium stygium – a rare glacial relict species.
Climacium dendroides
Cratoneuron filicinum
Plagiomnium rostratum
Scorpidium revolvens

After the masterclass back to the calciolous grassland quadrat to wrap up and lunch and then Dr M moved students on to the calciolous fen and the quadrat set up some hours ago now!

Having moved off the drier limestone soils down to where the water table is near the surface, the vegetation could hardly be more contrasting. With a wet and soggy fen peat substrate and vegetation with a characteristic  mix of fen calcicoles and dominance by a fist full of Cyperaceous and Poaceous monocots!

Carex dioica (Dioecious Sedge)
Carex echinata (Star Sedge)
Carex hostiana (Tawny Sedge)
Carex lepidocarpa (Long-stalked Yellow Sedge)
Carex panicea (Carnation Sedge)
Carex pulicaris (Flea Sedge)
Briza media (Quaking-grass)
Molinia caerulea (Purple Moor-grass)

Other species included: 

Drosera rotundifolia (Round-leaved Sundew)
Pinguicula vulgaris (Common Butterwort)
Primula farinosa (Bird’s-eye Primrose)
Succisa pratensis (Devil’s-bit Scabious)

Adding to the excitement, the Lycopod: Selaginella selaginoides (Lesser Clubmoss)

Having had the benefit of the Masterclass earlier, students identified the following bryophytes in the quadrat:

Calliergonella cuspidatum
Campylium stellatum
Cratoneuron filicinum
Hylocomium splendens
Scorpidium revolvens

No rest for the eXtreme botanical students, and after dinner evening work continued with  Cyperaceous theme with careful identification of Carex lepidocarpa (Long-stalked Yellow-sedge) using the advanced keys in the BSBI Sedge volume and the Book of Stace.

Then to finish, a shift to Poaceae and keying out a tall spiky grass with dark purplish spikelets from the quadrat in the species-rich fen in Tarn Fen on day 1.  After a few wrong turns, students reached a new genus for the field course module, Calamagrostis, but with the time having flown (not surprising with such extreme botanical enjoyment!) the specific epithet will have to wait until tomorrow!

Day 3 Sedge Tally:

The number of sedges new for the field course today totalled four:

Carex dioica (Dioecious Sedge)
Carex flacca (Glaucous Sedge)
Carex hostiana (Tawny Sedge)
Carex lepidocarpa (Long-stalked Yellow Sedge)

This takes the overall tally to thirteen, no wonder the Sedge Queen has been so full of Cyperaceous smiles today!