Abstract: There is an increasing interest in recording early colonisation of organisms when studying changes in distribution ranges induced by climate change. Here, I describe one population of Mentha cervina L. (Hart’s pennyroyal), naturalising in the wild at South Gare, v.c.62 North-east Yorkshire. Two other populations have been reported in Britain and none are known from Ireland. Of the three populations ever reported from the wild in Britain, two are still extant. It is unclear what vectors disperse M. cervina in Britain and whether the species is becoming increasingly naturalised or not. Diagnostic characters: digitate bracteoles and four calyx teeth, are provided to facilitate the recording of this mint species by field botanists.
“This project sought to determine whether there was a link between the age of freshwater habitats and the diversity of resident molluscs. Data was collected across Cumbria, Norfolk and Glasgow to analyse biodiversity while a variety of historical mapping software was used to determine the approximate age of said sites.”
“Sources used were: Oldmaps.co.uk, GoogleEarth and GIS. National grid references (NGR) were used to access historical maps of the area, which were compared in a GIS to determine the appearance of the water body. The times in which the water body first appeared in historical mapping were compared to that of previous maps to determine approximate age. Man-made water bodies had specific build dates, which were found by contacting various land managers and local bodies. Any water bodies that existed without change from the oldest available maps were recorded as 0 and they were assumed to be of natural origin.”
“I found that younger ponds have a higher species richness on average. The opposite result was found for lakes as there is a apparent decrease in species richness with younger lakes. The oldest lakes show some of the highest species richness throughout the sample group, suggesting that more mature lakes yield the highest mollusc species richness.”
“There are many potential reasons for this trend in mollusc diversity in relation to age. For example, eutrophication and accumulation of sediments may be the reason for the trend in pond mollusc species richness. As sediments build up over time, there may be less available habitat.
Over time ponds may also experience encroachment from vegetation, particularly trees which may lead to eutrophication; building up over time and leading to a poorer water quality of which some mollusc species may be unable to tolerate.”
“Whereas, it may be that the lakes that have been established for a longer period have accumulated more mollusc species over time. This could be for a number of reasons such as: colonisation, establishment of plant species (food source and habitat) as well as the quality of the water and the maturity of natural water purification systems. Younger lakes may not have developed these yet and so cannot support the same number of species; particularly those more delicate and vulnerable to sudden change.”
“These data suggest that there is a correlation between the age of a water body and the species richness of molluscs. While older ponds decrease in biodiversity with age, lakes behave in an opposing manner.
The implications of this is a call for increased protection of older lakes as these harbour the highest diversity. Findings also suggest a reduction in richness with age in ponds may be down to accumulation of pollutants as well as sediments. This, too, may call for increased management to regenerate ponds, maintaining diversity.”
“Further research will be carried out on other organisms such as aquatic plants, beetles and dragonflies to determine any wider correlations.”
“Thank you to LTE for funding this research project and to Dr Ambroise Baker, Dr Alan Law and Dr Carl Sayer for help with research. Thank you also to NERC Hydroscape research project for providing biodiversity data.”
Law A., A. Baker, C. Sayer, G. Foster, I.D.M. Gunn, P. Taylor, Z. Pattison, J. Blaikie, N.J. Willby (2019) The effectiveness of aquatic plants as surrogates for wider biodiversity in standing fresh waters. Freshwater Biology. https://doi.org/10.1111/fwb.13369
Article first published online: 15 July 2019
This is our first research paper based on of work conducted during my second postdoc part of the research programme Hydroscape. We present some of the data Alan and I collected during two seasons of field work (some of it reported here, and here and here) as well as applying Structural Equation Modelling, aka SEM, a statistical methods we learned during a one-week long PR Statistics course.
Freshwaters are among the most globally threatened habitats and their biodiversity is declining at an unparalleled rate. In an attempt to slow this decline, multiple approaches have been used to conserve, restore or enhance waterbodies. However, evaluating their effectiveness is time‐consuming and expensive. Identifying species or assemblages across a range of ecological conditions that can provide a surrogate for wider freshwater biodiversity is therefore of significant value for conservation management and planning.
For lakes and ponds in three contrasting landscapes of Britain (lowland agricultural, eastern England; upland, north‐west England; urban, central Scotland) we examined the link between macrophyte species, macrophyte morpho‐group diversity (an indicator of structural diversity) and the richness of three widespread aquatic macroinvertebrate groups (molluscs, beetles, and odonates) using structural equation modelling. We hypothesised that increased macrophyte richness and, hence, increased vegetation structural complexity, would increase macroinvertebrate richness after accounting for local and landscape conditions.
We found that macrophyte richness, via macrophyte morpho‐group diversity, was an effective surrogate for mollusc, beetle, and odonate richness in ponds after accounting for variation caused by physical variables, water chemistry, and surrounding land use. However, only mollusc richness could be predicted by macrophyte morpho‐group diversity in lakes, with no significant predicted effect on beetles or odonates.
Our results indicate that macrophyte morpho‐group diversity can be viewed as a suitable surrogate of macroinvertebrate biodiversity across diverse landscapes, particularly in ponds and to a lesser extent in lakes. This has important implications for the restoration, conservation, and creation of standing water habitats and for assessing their effectiveness in addressing the decline of global freshwater biodiversity. Management actions prioritising the development of species‐rich and structurally diverse macrophyte assemblages will be likely to benefit wider freshwater biodiversity.
In addition to my talk at the BES annual meeting, Althea Davies from the University of St Andrews and I had organised a session for which we invited keynote speakers on the theme: “Advancing our understanding of long-term ecology”
The Line up:
Maria Dornelas, University of St Andrews, UK: Temporal change in biodiversity change in the Anthropocene
Lizzy Jeffers, University of Oxford, UK: Plant controls on Late Quaternary whole ecosystem structure and function
Will Gosling, University of Amsterdam, Netherlands: Advancing palaeo-fire ecology
Helen Bennion, University College London, UK: Assessing the potential for aquatic plant recolonisation after local extirpation
Alistair Seddon, University of Bergen, Norway: Assessing ecological resilience using long-term ecological data: perspectives and prospects
Sandra Nogué, University of Southampton, UK: Comparative ecology of the Laurel forest pollen rain from Tenerife and La Gomera
Jack Williams, University of Wisconsin-Madison, USA: Ecological and Environmental Novelty
I was so excited when I received an email from the British Ecological Society (BES) saying that the abstract submitted with Sandra Nogue (University of Southampton) had been accepted for an oral presentation at the 2018 BES Annual Meeting!
And here I am presenting our review paper in preparation – thank you Sandra for taking this picture and many thanks also to the PollerGEN project for providing the illustration for the slide captured here.
Abstract: Modification of pollen production in response to global change: a review
How pollen abundance and quality impacts human–environment system is a significant focal point in: i) public health, with pollen-born allergies and asthma, ii) ecosystem services with crop pollination and nutrient cycling in nutrient-poor wetlands iii) global change ecology and conservation with reproductive limitation and vegetation regeneration. Atmospheric dispersal and pollinators are key dispersal mechanism currently investigated to quantify and forecast pollen impacts. However, pollen production by plants from natural, semi-natural and urban vegetation can be extremely sensitive to environmental conditions, while being at the same time the ultimate driver of these pollen impacts. Despite this crucial role, it is currently un-clear how pollen production will be modified by global change in the future. As a result, longer-term forecast of pollen impact may be associated with extremely large uncertainty.
As a first step towards addressing this key knowledge gap, we reviewed the environmental factors governing pollen production, in terms of pollen quantity and quality. We focussed on factors directly modifying pollen production, given existing vegetation cover and composition; and therefore excluded factors such as habitat loss. Studies tended to focus on the response of a single, or a small set of species, to a single factor. There appears to be a dearth of research studying pollen response at the vegetation plot or ecosystem level. The principal factors driving pollen production in the species studied were nutrient enrichment, increased atmospheric CO2 levels, changes in UV levels, and climatic factors modifying water availability, seasonality and temperatures. Other factors, including biological interaction such as grazing were extremely under-researched. The studied factors often had effects in opposite directions but the outcome of interaction between factors was rarely quantified. In addition, we found a body of literature that concerned flowering response. However, there was only limited quantitative data linking flowering response to pollen production.
My teaching and research are focussed on understanding how biodiversity and ecosystems respond to environmental change. This understanding is critically important to developing evidence-based policies to conserve biodiversity, protect the environment and maintain ecosystem services in the current context of global change.
Professor Helen Bennion presented some of our NERC Hydroscape research at the joint meeting of the International Paleolimnology Association and the International Association of Limnogeology, Stockholm, Sweden, June 18-21, 2018 (see site).