Arctic Tundra

Arctic Tundra

1. Oil and gas industry

   • Water
     • Melting of prmfrst + snow cover ^ run off + river discharge
       • Flooding ^ likely
       • In summer- wetlands, ponds + lakes ^ extensive
         • ^ evaporation
       • Localised bc industrial activity
         • ^ erosion
         • Run-off
     • Strip mining of aggregates- construction
       • Creates artificial lakes
         • ^ warmth than land
         • Distruct drainage + expose permafrost to further melting
         • ^ water evaporated
     • Drainage networks disrupted by road construction + seismic explosions used to prospect for O + G
     • H2O abstracted from creeks + rivers for industrial use and for building of ice roads in winter reduce localised run off
   • Carbon
     • Permafrost- major carbon store in tundra
       • Sensitive to changes in thermal balance
         • Balance disrupted due to oil and gas companies-caused melting of permafrost
         • Natural balance of temp through year
     • Melting associated with
       • Dust deposition on roadsides creating darkened surfaces- ^ absorption of sunlight
         • Albedo
       • Removal of veg cover- insulates permafrost
         • Exposed
       • Construction + operation of oil and gas installations
         • Diffusing heat
     • Permafrost melting releases co2 7-40m tonnes/year- and methane 24000-114000 tonnes
     • Gas flaring + oil spillages put co2 in atmosphere
       • Destruction of tundra veg reduces PHS and uptake of co2 from atmosphere
         • Localised
           • Also in other locations
         • Veg ^ due to warmer temps + less snow cover
           • Long term- slow C Cycle
           • Short term- fast C Cycle
       • Small food web- few trophic levels
     • Prmfst melting leads to ^ runoff and river discharge ^ flooding risk
       • ^ evaporation
       • Drainage networks disrupted by road construction
       • h2o extracted from creeks + rivers for industrial use reduce localised run off
     • Slow growing tundra veg- regeneration + recovery from damage takes decades
     • Fragile ecosystem
       • Decompostion speeds up- ^ co2 released + ^ in litter

2. Management strategies

   • Development- deliberate destruction of permafrost
     • Melting permafrost
       • Material not as solid
       • h2o cycle significantly changed
       • Sink holes exposed
       • More C released and exposed
   • Insulation pads for roads
     • Insulate+ protect prmfrst below
     • Albedo lower on tarmac road
     • ^ stable road + infrastructure
     • V. expensive
   • Elevated Infrastructure
     • Less impact on warming surface
     • Protect ground from heat from industry and industrial processes
   • Lateral Drilling
     • ^ technology- thousands of feet drilled laterally
     • Don't have to drill as much
     • Need technology
     • Vertical drilling- ^ bore holes
   • High tech + GIS
     • Device collects data for you
     • Map different features- landscape and below
   • Refrigerated supports
     • Draw heat from piles stay cold

3. Carbon

   • C flux concentrated in summer months when active layer thaws. plants grow rapidly In short summer. long daylight hours allow flowering and fruit in a few weeks. tundra biomass small depending on veg cover
   • in growing season tundra plants input C rich litter into soil. microorganism activity ^ releasing co2 through respiration. co2 ch4 emissions not just confined in summer. in winter pockets of unfrozen soil + h2o = sources of ch4 + co2
   • prmfst vast C sink. accumulation due to low temps- slow decomposition of dead plant material. amount of c in tundra soils 5x ^ in above ground biomass.
   • snow cover may insulate microbial organisms, allowing some decomposition despite low temps
   • in past prmfst functioned as C sink. today GW-might become a C source. outputs of C from prmfst ^, ^temps have stimulated plant growth and ^ uptake of co2. ^ plant litter entering store. possible C budget remains in balance

4. Water

   • limited groundwater and soil moisture stores. prmfst = barrier to infiltration, percolation, recharge and groundwater flow
   • Limited transpiration, sparseness of veg cover + short growing season
   • Extensive wetlands, ponds, lakes on tundra during summer. Temporary store of liquid water due to prmfst, impedes drainage
   • small stores of moisture in atmsphr, owing to low temps, reduce absolute humidity
   • Accumulation of snow + river/lake ice during winter months. melting of snow/ river + lake ice and uppermost active layer of prmfst in spring + early summer, results in sharp ^ in river flow
   • Low PPT, most = snow
   • Low rates of evaporation, much of suns energy melts snow so temps remain low and inhibit convection. surface and soil water frozen for most of year

5. Seasonal Changes

   • Water
     • Flows + stores of H2O influenced by temp, relief, + rock permeability
     • Lots of H2O stored as prmfst- temp usually -0 all year
       • Liquid H2O only flow in summer - active layer on top of prmfst will thaw- h2o flow on surface
     • Meltwater form millions of pools + shallow lakes, stud tundra landscape
       • winter -0 temp prevent evapotranspiration
         • Summer some occurs - standing h20, saturated soils + veg
       • deep prmfst - h2o can't infiltrate soil- tundra drainage = poor
     • Ancient rock surface reduced to gently undulating plain by hundreds of years of weathering + erosion
     • Low humidity all year, ppt sparse
       • Crytalline rocks dominate geology, ^prmfst
         • Low permeability
     • Impede drainage + waterlogging only as a result of minimal relief or chaotic glacial deposits
   • Carbon
     • Owing to permeability of prmfst, rock permeability, porosity + mineral decomposition of rocks exert little influence of H2O + C cycle
     • Low temps + waterlogging slow decomposition and flow of CO2 to atmsphr
     • Phs + NPP low, with growing season barely 3 months
       • Long hours of daylight in summer
     • Most C in tundra locked away for past 50,000 years, stored as prmfst as partly decomposed plant remains
     • Low temps, unavailability of liquid h2o for most of year + parent rocks containing few nutrients, limit plant growth
       • Total C store of biomass - relatively small