LAKES IN DRYLANDS: VARIATION IN CHIRONOMID COMMUNITIES IN WESTERN MONGOLIA LAKES R. William Bouchard Jr. Barbara L. Hayford Leonard C. Ferrington, Jr.

Western Mongolia Western Mongolia is a semi-arid to arid – Desert steppe, typical steppe, mountain steppe, alpine forests, meadows, and glaciers Eleven Mongolian Special Protected Areas and a UNESCO world heritage site

Western Mongolia Numerous lakes that range from alpine to lowland evaporative basin lakes Lakes exhibit strong, natural environmental gradients (e.g., salinity, nutrients) High elevation, freshwater Low elevation, saline (Uvs Nuur, UNESCO World Heritage Site) Low elevation, freshwater

Threats Climate change can impact: salinity, timing of salinity, hydrograph, temperature and thermal stratification Over grazing and high density of domesticated grazers western Mongolia Desertification caused by climate change and intensive land use in arid and semi-arid lands

OBJECTIVE Climate change, over grazing and collectively desertification threaten diversity thus our objectives are: 1.To document diversity of a common lake invertebrate, the non-biting midge (Diptera: Chironomidae) 2.To relate environmental conditions to diversity, unique communities, and individual taxa in lakes of Western Mongolia

Background Diatom communities influenced largely by salinity and nutrient gradients

Methods 54 lakes Strong environmental gradients (elevation, size, depth, nutrients, salinity) Shinneman et al. (2009) Diatoms communities influenced by salinity and nutrient gradients

From Shinnerman et al. (2009)

Kranzfelder et al. (2015) Journal of Visualized Experiments 101, e Single pupal exuviae sample from each lake 500 count subsamples slide mounted Identification to species/morphospecies

Chironomid Diversity 117 species collected 54 taxa after removing rare taxa (taxa present in ≥5% of sites)

Environmental Variables Latitude, Longitude, Elevation, Water Temperature, Specific Conductance, pH, Dissolved Oxygen, Secchi Depth, Chlorophyll-a, Total Phosphorus, Total Nitrogen, Nitrate, Organic Nitrogen, Kjeldahl Nitrogen, Ammonia, Chloride, Sulfate, Sodium, Magnesium, Aluminum, Silicon, Potassium, Calcium, Iron, Manganese, Dissolved Organic Carbon, Dissolved Inorganic Carbon, Carbonic Acid, Bicarbonate, Carbonate, Lake Type

Midges and Lake Attributes Partial constrained correspondence analysis (cca; R 3.2.2, “vegan” package) performed individually on all physical and chemical variables to identify those which were significantly (P ≤ 0.01) related to chironomid community composition Total Nitrogen Kjeldahl Nitrogen Specific Conductance Chloride Sulfate Sodium Magnesium Silicon Potassium Dissolved Organic Carbon Bicarbonate Carbonate

Redundant Measures SalinityNitrogenInorganic CarbonIndependent Specific ConductanceTotal NitrogenDissolved Organic CarbonSilicon ChlorideKjeldahl nitrogenBicarbonate SulfateCarbonate Sodium Magnesium Potassium

CCA cca; R 3.2.2, “vegan” package

Salinity GrpClassification Salinity (ppt) FFreshwater<0.5 OOligohaline0.5-5 MMesohaline5-18 PPolyhaline +>18 metaMDS; R 3.2.2, “vegan” package

Taxa Richness metaMDS, ordisurf; R 3.2.2, “vegan” package

A Lake Typology Categorized lakes based on size, depth and salinity Classification Shallow Freshwater Deep Freshwater Small Shallow Saline Small Deep Saline Large Saline Terminally Valley Saline Hypersaline

Lake type comparisonTp Large SalineShallow Freshwater Large SalineDeep Freshwater Large SalineHypersaline Large SalineTerminal Valley Saline Large SalineSmall Shallow Saline Large SalineSmall Deep Saline Shallow FreshwaterDeep Freshwater Shallow FreshwaterHypersaline Shallow FreshwaterTerminal Valley Saline Shallow FreshwaterSmall Shallow Saline Shallow FreshwaterSmall Deep Saline Deep FreshwaterHypersaline Deep FreshwaterTerminal Valley Saline Deep FreshwaterSmall Shallow Saline Deep FreshwaterSmall Deep Saline HypersalineTerminal Valley Saline HypersalineSmall Shallow Saline HypersalineSmall Deep Saline Terminal Valley SalineSmall Shallow Saline Terminal Valley SalineSmall Deep Saline Small Shallow SalineSmall Deep Saline MRPP Multi Response Permutation Procedure (MRPP) tests whether communities are distinct from one another Multi-Response Permutation Procedure (MRPP; PC-ORD 6)

Taxon CodeTaxonGroup CRPTRWB1Cryptotendipes RWB pe1Large Saline CRYPSUPCryptochironomus supplicansLarge Saline CLDORWB1Cladotanytarsus RWB pe1Large Saline CLAD0VIRCladopelma viridulumShallow Freshwater CRICRWB3Cricotopus (Cricotopus) RWB pe3Shallow Freshwater PTNYDIMParatanytarsus cf. dimorphisShallow Freshwater PROHRWB1Procladius (Holotanypus) RWB pe1Shallow Freshwater CRISRWB4Cricotopus (Isocladius) RWB pe4Shallow Freshwater ORTHPOGOrthocladius (Pogonocladius) consobrinusDeep Freshwater ABLMONAblabesmyia monilisDeep Freshwater TANYTPUNTanypus punctipennisDeep Freshwater DICRLOBDicrotendipes lobigerDeep Freshwater CRICRWB2Cricotopus (Cricotopus) RWB pe2Deep Freshwater CRIISSYLCricotopus (Isocladius) sylvestrisDeep Freshwater PSECPBREPsectrocladius (Psectrocladius) brehmiDeep Freshwater CRICRWB9Cricotopus (Cricotopus) RWB pe9Hypersaline CHIRRWB2Chironomus RWB pe2Terminal Valley Saline CLDORWB2Cladotanytarsus RWB pe2Terminal Valley Saline CRIISLAECricotopus (Isocladius) laetusTerminal Valley Saline PROHRWB4Procladius (Holotanypus) RWB pe4Small Shallow Saline GLYPBARGlyptotendipes barbipesSmall Shallow Saline CGNARWB1Chironomini Genus A RWB pe1Small Deep Saline CLDORWB4Cladotanytarsus RWB pe4Small Deep Saline CRIISORNCricotopus (Isocladius) ornatusSmall Deep Saline PSECPRWB1Psectrocladius (Psectrocladius) RWB pe1Small Deep Saline Indicator Species Calculated indicator species to see which taxa best defined these communities

Indicator Species Psectrocladius (Psectrocladius) brehmi glm; R Cricotopus (Isocladius) laetus

Summary Taxa rich fauna (>100 species) Distinct communities that largely follow a salinity gradient (although nutrients are probably also important) Unique habitats face threats from climate change and changing land use

Thanks National Science Foundation (NSF) grant DEB National Science Foundation (NSF) grant DEB Jim Almendinger – Science Museum of Minnesota Jim Almendinger – Science Museum of Minnesota Mark Edlund – Science Museum of Minnesota Mark Edlund – Science Museum of Minnesota