On the Active Role of Plants on Land Atmosphere Processes Amilcare - PowerPoint PPT Presentation

On the Active Role of Plants on Land ‐ Atmosphere Processes Amilcare Porporato Duke University

From stochastic rainfall to soil moisture dynamics and plant water stress INPUT: RAINFALL (intermittent- 20 stochastic) h Precipitation 15 ) (mm day t 10 5 0 interspace Evapo- transpiration canopy 0.25 q (%) 0.15 Troughfall Runoff Runoff 0.05 150 200 250 300 350 Z r Z r Julian D ay Effective porosity, n Effective porosity, n Sevilleta, NM Leakage Courtesy of Eric Small

Soil Moisture PDF: climate soil and vegetation   Rodriguez-Iturbe et al., Proc. c du         Royal Soc. A, 455, 3789, 1999 p ( s ) Exp s     Laio et al. AWR 2001; ( s ) ( u )   s Porporato et al. Am. Nat., 2004 Experimental verification Salvucci G. (2001) Water Resour. Res. 37(5), 1357-1365.

Soil moisture control on C-N cycling Biological fixation Wet and dry deposition Litter PLANTS Denitrif. Ammonia Plant Uptake SOM volatilization Litter Nitrification + - NO 3 NH 4 Ammonification Microbes Humus Immobilization Leaching Adsorption (desorption) Porporato et al. AWR 2003; Manzoni et al., Science 2008

Calhoun Critical Zone Observatory Critical Zone Observatories Calhoun, 1950 circa

NSF ‐ FESD – frontiers in earth system dynamics Geo ‐ genomics – geology, eco ‐ hydrology and evolution of biodiversity in the Amazon

Weathering • Ecohydrological mediation of weathering – soil alternate states: two brief examples – bistability and – rapid change in weathering and carbon sequestration during carboniferous. stomatal control CAM photosynthesis

Plants, Leaching & Soil formation Devoninan (400 ‐ 360 Ma) and Carboniferous (360 ‐ 300 Ma) Atmosphere �� � � �� � � ��� �� � � � � � � � �� ET Rainfall PS, photosynthesis Q Respiration, R Infiltration Organic mat’l �� � �� � J � � � �� � �� � �� �� � � �� � � � � � � � � � �� �� � �� � �� Soil depth, h Soil moisture Chemical Mineral weathering soil L, percolation & Physical export of dissolved weathering carbonates Morel and Hering, � � � � � � �� � � ��� � � � 2 �� � �� � � ��� � Aquatic chem.

Simplified model Quasi ‐ steady state assumptions in the soil solution CO2 proxy data from: DL Royer, Geochimica et Cosmochimica Acta 70 (2006) � �� � �� � � � � � � , � � � � � � � � �� � � �� � � � �� � � � � � ��� �� � �� � ⋅ � � � � � ��� we know that L decreases with h …  increased infiltration?  Increased convective precipitation?

Ecohydrology and photosynthetic pathways Water stress function on Farquhar’s model of photosynthesis only in 2004: Daly et al. JHM (2004) Tuzet et al. PCE (2004) Water stress (  l ) site of site of Calvin Calvin cycle cycle Chloroplasts in the mesophyll site of light H2O here for reactions 10 photolysis

C3 photosynthesis – Calvin cycle: a chemical engine to produce sugar Carboxylase/Oxygenase … G3P 3C compound Triose 3C sugar 11

Weathering • Ecohydrological mediation of weathering – soil alternate states: two brief examples – bistability and – rapid change in weathering and carbon sequestration during carboniferous.

C4 photosynthesis: Krantz anatomy bundle CO2 pump sheath cell mesophyll cell 13

greater WUE Kramers and Boyer 1995 very productive crops with water and energy availability � � � � a � � �� � b � � � � Wheat � � � � Corn � � �� � � � 12 �� � � � � � � � � � � � � 4 � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � �� � Y � ton ha � 1 � Y � ton ha � 1 � � � � � � � � � � � � � � � � � � � � � � � � � � � 8 � � � � �� � � � � � � � � � � � 2 � � � � � � � � � � � 4 � � � � � � �� � � � � � � � � � � � � � � 0 0 0 200 400 0 200 400 600 ET seas � mm � ET seas � mm � Vico and Porporato, AWR (2012)

A curious analogy… CO2 pump

But C4 is more sensitive to water stress Weibull-type vulnerability curve C3 C3      c   )       C4 l f ( a Exp l     d   C3 C4 C4 1 E/Ep C3 C4 0.5 C3 C4 C4 0 0 0.5 1 soil moisture Vico and Porporato, C3 and C4 photosynthesis under ‐ water stressed conditions, Plant and soil (2008) 16

Sugarcane Largescale land ‐ atmosphere feedback?

ABL development and convective precipitation as the ABL grows, the conditions for convective precipitation: 1) LCL crossing 2) CAPE>400 18

Slab or mixed ‐ layer models of the ABL • Idealized ABL – Hydrostatic atmosphere – Homogeneous horizontal conditions – Well ‐ mixed vertically (instantaneous) – Zero ‐ order “jump” at capping inversion – No latent heat release • Simplified profiles/geometry – Constant in mixed layer – Linear in free atmosphere

It is a good approximation  : e.g., Large Eddy Simulation of ABL after Stevens – J. Atm. Sci. (2007)

 c h d dh        – Surface energy balance: H c ( ) p p f dt dt h dq q dh      E ( q ) f dt dt      H c g ( )   dh ( 1 2 ) H  p a 0 a    dt c h p g g     s a E ( q q )  w i a g g s a     Q H E n w w – Conservation equations in the mixed layer:  d dh        c h H c ( ) p p f dt dt dq dh       h E ( q q ) w f dt dt e.g., Garrett 1994 (   ) dh 1 2 H  Porporato BLM 2009   dt c h  p 21

s=0.25 s=0.32 s=0.25 s=0.32 400 400 8 8 300 300 Altitude (km) Altitude (km) J/kg J/kg 4 4 200 200 2 2 100 100 0 0 0 0 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 time (hr) time (hr) time (hr) time (hr) s=0.38 s=0.45 s=0.38 s=0.45 400 400 8 8 300 300 Altitude (km) Altitude (km) J/kg J/kg 4 4 200 200 2 2 100 100 0 0 0 0 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 time (hr) time (hr) time (hr) time (hr) Yin et al. (in preparation) Huang et al. WRR (2007)

(A) Dry soil advantage (E) No crossing regime (D & F) LCL crosses at certain soil conditions but CAPE<400J/Kg (B) Transitional regime wet (C) Wet soil unstable advantage regime s max soil moisture that likely triggers strongest convection for the given atmospheric conditions Yin et al. (in preparation)

C3 vs C4 s=0.3 s=0.8 2 2 1.5 1.5 Altitude (km) Altitude (km) 1 1 0.5 0.5 0 0 0 2 4 6 8 0 2 4 6 8 time (hr) time (hr) s=0.8 s=0.3 800 800 600 600 (J/kg) (J/kg) 400 400 200 200 0 0 0 2 4 6 8 0 2 4 6 8 time (hr) time (hr)

CAM Weathering = Crassulacean • Ecohydrological mediation of weathering – soil alternate states: two brief examples Acid – bistability and Metabolism – rapid change in weathering and carbon sequestration during carboniferous. CAM pathway

Thick-leaved orchid: Phalaenopsis amabilis 27

Storage of malic acid in cell vacuoles + control system (circadian rhythm) Bartlett, Vico and Porporato, Plant and Soil (2014) Hartzell et al. JTB in revision

Pursuing the analogy a bit further… Porporato et al. in preparation 2014 • Similar evolutionary sequence • C4: low CO2  turbocharger: low oxygen (more power/works well at high elevations) • CAM  hybrid: storage limits and costs: variability is essential NOBEL, P.S. Biologia ambiental. K. Orkun and J. Michalek, Influence of driving patterns on In: Agroecologia, cultivo e uso da palma forrageira. life cycle cost and emissions of hybrid and plug ‐ in electric FAO, 1995. SEBRAE ‐ PB. p.36 ‐ 48. 216p. 2001. vehicle powertrains. Energy Policy 60 (2013): 445 ‐ 461.

Model for CAM photosynthesis  Demand ‐ driven dM    A R A  sv dv vc stomatal dt  Circadian rhythm dz conductance     M ( z , T ) M  E l dt z A c (c i ,T l ,  ) classic Farquhar et al. (1981) model Plant capacitance Bartlett, Vico and Porporato, Plant and Soil (2014) Hatzell et al. JTB in revision

results Clusia minor Agave tequiliana

Comparison of C3, C4 and CAM plants Decreasing rainfall frequency

Back to our analogy C4 C3 CAM

Conclusions • Work in progress… • Fascinating interactions between plant and their environment which are impacted by and in turn control the water cycle • Important for long term dynamics of soils , biogeochemical cycles and landscape formation • Optimizing our management of soil and water resources ( quantitative answers to the problem of sustainability )