Regional impacts of warming on biodiversity and biomass in high latitude stream ecosystems across the Northern Hemisphere

Warming can have profound impacts on ecological communities. However, explorations of how differences in biogeography and productivity might reshape the effect of warming have been limited to theoretical or proxy-based approaches: for instance, studies of latitudinal temperature gradients are often conflated with other drivers (e.g., species richness). Here, we overcome these limitations by using local geothermal temperature gradients across multiple high-latitude stream ecosystems. Each suite of streams (6-11 warmed by 1-15°C above ambient) is set within one of five regions (37 streams total); because the heating comes from the bedrock and is not confounded by changes in chemistry, we can isolate the effect of temperature. We found a negative overall relationship between diatom and invertebrate species richness and temperature, but the strength of the relationship varied regionally, declining more strongly in regions with low terrestrial productivity. Total invertebrate biomass increased with temperature in all regions. The latter pattern combined with the former suggests that the increased biomass of tolerant species might compensate for the loss of sensitive species. Our results show that the impact of warming can be dependent on regional conditions, demonstrating that local variation should be included in future climate projections rather than simply assuming universal relationships

Invertebrate pictures. Data supporting the thesis, "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques"

Supplementary material of the PhD thesis entitled: "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques". This complements Chapter 5 of the thesis.Contains 1,722 high quality pictures (863 Mb uncompressed) in 30 folders (one per taxonomic group) used to identified all morphospecies of aquatic macroinvertebrates found in the Okavango Delta (Botswana). The folder includes pictures of all life stages and also of other non-macroinvertebrate organisms, such as zooplankton, Platyhelminthes, parasites, terrestrial and semiterrestrial taxa.Pictures were taking after sorting of specimens, using an iPhone 11 pro at 100-1000x magnification. There are several pictures of each morphospecies showing key features for its identification. Each individual picture has been cropped and edited using the iPhone picture edition software

Supplementary material 4 (Chapter 6). Data supporting the thesis, "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques"

Supplementary material of the PhD thesis entitled: "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques". Contains Chironomidae (Diptera, non-biting midges) data from sorting of samples from recession and peak phase of the flood, also analysis of distribution per sampling site, total number of morphospecies and source data used to create graphs for the thesis. It complements Chapter 6 of the thesis

Supplementary material 2 (Chapter 3). Data supporting the thesis, "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques"

Supplementary material of the PhD thesis entitled: "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques". The file contains tables of references for Chapter 3 and tables with species number for each main group of freshwater organisms found in the Okavango Delta (Botswana)

Supplementary material 3 (Chapter 5). Data supporting the thesis, "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques"

Supplementary material of the PhD thesis entitled: "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques". This is the master spreadsheet that contains all data from the sorting of bulk macroinvertebrate samples and chironomid slides. It is divided into 12 sheets. It also includes a list of all morphospecies, an analysis of morphospecies per site and a comparison between eDNA and taxonomical data. It complements Chapter 5 of the thesis

Chironomidae pictures. Data supporting the thesis, "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques"

Supplementary material of the PhD thesis entitled: "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques". Contains 2,194 high quality pictures (1.57 Gb) used to identified all morphospecies of Chironomidae (Diptera) found in the Okavango Delta (Botswana). The folder includes pictures of larvae, pupae, pupal exuviae, adults and anecdotic findings such as deformities. Pictures were taking after sorting and mounting of specimens on microscope slides, using an iPhone 11 pro at 100-1000x magnification. There are several pictures of each morphospecies showing key features for its identification. Each individual picture has been cropped and edited using the iPhone picture edition software

Supplementary material 1 (Chapter 3). Data supporting the thesis, "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques"

Supplementary material of the PhD thesis entitled: "Characterising freshwater macroinvertebrate diversity in the Okavango Delta (Botswana) using taxonomic and molecular techniques". Contains conservation status, species taxonomic classification, habitat, ecology, distribution, site coordinates, references and notes for each group of freshwater organisms found in the Okavango Delta (Botswana)

Finding clean water habitats in urban landscapes: professional researcher vs citizen science approaches

This study investigated patterns of nutrient pollution in waterbody types across Greater London. Nitrate and phosphate data were collected by both citizen scientists and professional ecologists and their results were compared. The professional survey comprised 495 randomly selected pond, lake, river, stream and ditch sites. Citizen science survey sites were self-selected and comprised 76 ponds, lakes, rivers and streams. At each site, nutrient concentrations were assessed using field chemistry kits to measure nitrate-N and phosphate-P.The professional and the citizen science datasets both showed that standing waterbodies had significantly lower average nutrient concentrations than running waters. In the professional datasets 46% of ponds and lakes had nutrient levels below the threshold at which biological impairment is likely, whereas only 3% of running waters were unimpaired by nutrients. The citizen science dataset showed the same broad pattern, but there was a trend towards selection of higher quality waterbodies with 77% standing waters and 14% of rivers and streams unimpaired.Waterbody nutrient levels in the professional dataset were broadly correlated with landuse intensity. Rivers and streams had a significantly higher proportion of urban and suburban land cover than other waterbody types. Ponds had higher percentage of semi-natural vegetation within their much smaller catchments. Relationships with land cover and water quality were less apparent in the citizen-collected dataset probably because the areas visited by citizens were less representative of the landscape as whole.The results suggest that standing waterbodies, especially ponds, may represent an important clean water resource within urban areas. Small waterbodies, including ponds, small lakes < 50 ha and ditches, are rarely part of the statutory water quality monitoring programmes and are frequently overlooked. Citizen scientist data have the potential to partly fill this gap if they are co-ordinated to reduce bias in the type and location of the waterbodies selected