Editing Askham Bog (section)

==Natural history==
===Herbaceous plants===
[[File:Rubus caesius fruit - Keila.jpg|thumb|European dewberry]]
The diverse flora of Askham Bog is similar to plant communities in southern England.<ref name = "FitterSmith"/> Notable species include [[Ranunculus lingua|greater spearwort]], [[Stellaria palustris|marsh stitchwort]], [[Cladium mariscus|saw sedge]], [[Thelypteris palustris|marsh fern]], [[Rumex hydrolapathum|great water dock]], [[Cirsium dissectum|meadow thistle]], [[Calamagrostis canescens|purple small reed]], ''[[Carex appropinquata]]'' and [[Hottonia palustris|water violet]]. Askham Bog also holds the largest and most north-eastern colony in England of the rare gingerbread sedge ''[[Carex elongata]]'',<ref>David R.&nbsp;W. 1978. The distribution of ''Carex elongata'' in Britain. ''Watsonia'' '''12''': 158–60.</ref> and is renowned for the presence of [[Osmunda regalis|royal fern]].

The vegetation of Askham Bog can be divided into two main groups, reflecting the broad underlying dichotomy between basic and acidic soil. One is a species-rich fen community around the margins. This includes characteristic species such as [[Filipendula ulmaria|meadowsweet]], [[Thalictrum flavum|common meadow rue]], [[Urtica dioica|stinging nettle]], [[Galium palustre|marsh bedstraw]], [[Rubus caesius|dewberry]], [[Solanum dulcamara|bittersweet]], [[Scutellaria galericulata|skullcap]], [[Lysimachia vulgaris|yellow loosestrife]], [[Lysimachia nummularia|creeping Jenny]] and [[Poa trivialis|rough meadow grass]]. The other community is a species-poor acid one towards the centre, including species such as ''[[Sphagnum palustre]]'', [[Molinia caerulea|purple moor grass]], ''[[Rubus fruticosus]]'' and [[Lonicera periclymenum|honeysuckle]].<ref name = "Fitter1980"/> Although the drop in pH and elevational increase on the peat domes is attributable to sphagnum growth,<ref name = "Fitter1980"/> no sphagnum has been found in one vegetation assemblage characterized by honeysuckle and ''Rubus fruticosus'' within the acid centre of the bog.<ref name = "Wilson">Wilson K.&nbsp;A., Fitter A.&nbsp;H. 1984. The role of phosphorus in vegetational differentiation in a small valley mire. Journal of Ecology 72: 463–473.</ref> This appears to be inconsistent with the usual course of succession and may be explained by unusually high concentration of inorganic [[phosphate]].<ref name = "Wilson"/> Low water tables in the raised area may promote mineralization of phosphate, with low pH counteracting microbial conversion to organic phosphate, so that the resultant high inorganic phosphate component in the raised peat favours growth of this plant community.<ref name = "Wilson"/>

===Birds===
Over 90 bird species have been recorded at Askham Bog, attracting both winter and summer visitors. Despite the proximity of potential sources of human disturbance, the bog provides suitable refuge for wildlife within a relatively unfavourable agricultural landscape and offers a rich supply of fruit and seed supply in winter and invertebrates in summer.<ref name = "FitterSmith"/> Known resident species include [[marsh tit]], [[willow tit]], [[Eurasian treecreeper|treecreeper]], [[common kingfisher|kingfisher]], [[goldcrest]], [[Eurasian bullfinch|bullfinch]], [[tawny owl]], [[common buzzard|buzzard]], [[Eurasian sparrowhawk|sparrowhawk]] and sometimes [[Eurasian green woodpecker|green woodpecker]]<ref name = "yorkbirding">{{cite web |url=http://yorkbirding.org.uk/sites/askham-bog/ |title=Askham Bog YWT |publisher=York Ornithological Club |accessdate=14 May 2020}}</ref> Winter visitors include [[fieldfare]], [[redwing]], [[brambling]], [[Eurasian siskin|siskin]], [[lesser redpoll]], [[European goldfinch|goldfinch]], [[common snipe|snipe]], [[jack snipe]], [[Eurasian woodcock|woodcock]], [[Eurasian coot|coot]] and sometimes [[common grasshopper warbler|grasshopper warbler]].<ref name = "yorkbirding"/> All migrant warblers have been found at the bog in spring and summer,<ref name = "yorkbirding"/> with the reed beds in the northeast part in Near Wood comprising an important colony for [[Eurasian reed warbler|reed warblers]].<ref name = "FitterSmith"/>

===Invertebrates===
Askham Bog is nationally recognised for its diverse invertebrate fauna, including a variety of water beetles such as  [[Haliplidae]], [[Noteridae]], [[Dytiscidae]] and [[Gyrinidae]]. The bog is also home to some rare beetle species including ''Dromius sigma'', ''Agabus undulatus''; alongside one record of ''Pselaphus dresdensis'' which has been found in moss from pond margins at the bog, the only known location in England.<ref name = "FitterSmith"/> Beetle abundance and species richness have been decreasing at Askham Bog since the early 20th century.<ref name = "FitterSmith"/> This coincides with the establishment of a municipal landfill site at the adjacent Challoner's Whin.<ref name="ywtreserves"/> Other characteristic insect species include the [[Diarsia florida|fen square-spot moth]]<ref name = "LP"/> and the [[Anax imperator|emperor dragonfly]].<ref name="ywtreserves">{{cite web |url=http://www.ywt.org.uk/reserves/askham-bog-nature-reserve |accessdate=15 April 2018 |title=Askham Bog Nature Reserve |publisher=Yorkshire Wildlife Trust}}</ref>

There is a large proportion of wetland indicator spider species given the relatively dry status of the reserve and gradual encroachment by trees. This may be because the present spider community reflects historic moisture levels within the bog and is yet to completely respond to the habitat changes.<ref name = "Oxford"/> A very rare spider species ''Cornicularia kochi'' (O.P.-C) in its hundreds was once recorded in piles of cut-down ''Phragmites'' during winter.<ref name = "Smith"/>

===Mammals and amphibians===
Typical amphibians of Askham Bog include [[Rana temporaria|common frog]], [[Bufo bufo|common toad]], and [[Triturus vulgaris|smooth newt]]. Typical mammals include [[roe deer]] and [[red fox]]es. The [[European water vole|water vole]] was once common at Askham Bog, but has now been largely displaced by invasive [[American mink]].<ref name = "yorkbirding"/>