Russian Academy of Sciences A.M. Obukhov Institute of atmospheric - PowerPoint PPT Presentation

Russian Academy of Sciences A.M. Obukhov Institute of atmospheric physics Laboratory of mathematical ecology Nikolay N. Zavalishin e-mail: nickolos@ifaran.ru Modelling the biotic turnover in ecosystems of permafrost regions of the Northern EuroAsia under climate change

Similarity and differences of a biotic turnover in terrestrial ecosystems - living form diversity of plants constituting the basis for terrestrial ecosystems serves a source for structural complexity of biotic turnover; - small amount of exchanging processes controlled by similar mechanisms in different ecosystems initiates universality in the cycle functioning. (Basilevich and Titlyanova, 2008) Сходства и различия биотического круговорота в наземных экосистемах - разнообразие жизненных форм растений , составляющих основу наземных экосистем , является источником сложности структуры круговорота ; - небольшое число обменных процессов , тождественных по своим механизмам в различных экосистемах , порождают универсальность функционирования круговорота . ( Базилевич и Титлянова , 2008)

Model classes for biotic turnover Detailed simulation Qualitative “minimal” models models Synthesis - ?

Main stages in mathematical modelling of biological turnover in ecosystems on the annual time scale - aggregation of complicated static schemes of biological - methods of aggregation and turnover in terrestrial ecosystems to the simplest their verification ? variants; - design and calibration of dynamic models for carbon - how to select flow-storage and/or combined carbon-nitrogen cycling (turnover) in dependencies ? ecosystems on the basis of aggregated static schemes; - verification of correspondence between model steady - how to interpret multiple states and real stable ecosystem types ; equilibria ? - calculation of stability boundaries for steady states - how to avoid undesirable and oscillations of single and/or combined cycles, study stability boundaries ? of their evolution under input flows and parameter variations; - how to reduce uncertainties in - numerical estimations of changes in carbon and/or the solution under uncertainties nitrogen functioning which can be considered as a in initial data ? reaction of ecosystems to external natural and anthropogenic perturbations. Problems and uncertainties

Tundra and forest tundra ecosystems in permafrost regions of Northern Euroasia Tundra peatland Distribution patterns of boreal forests ( shaded area ) and southern boundaries of the zones of continuous permafrost ( thick broken line ) and those of discontinuous permafrost ( thin broken line ) in northern hemisphere. Location of Tura is indicated by an asterisk . Dots and numerals: Moscow (1), Krasnoyarsk (2), Ulaanbaatar (3), Yakutsk (4), Fairbanks (5), Edmonton (6), Winnipeg (7), and Montreal (8). Larch sparse forest Photos from (Bazilevich and Titlyanova, 2008) (Forest ecosystems of the Enisey meridian, 2002)

Biotic turnover in tundra and forest tundra ecosystems of permafrost region ? Local ecosystem of moss-shrub tundra at the Taymyr peninsula (Tareya): Local low-parametric dynamic biotic cycles of carbon, nitrogen and mineral elements model of coupled carbon- (Bazilevich et al., 1986; Bazilevich and Gilmanov, 1985) nitrogen cycles with climatic parameterization and steady states corresponding to tundra ecosystem types Photo from (Bazilevich and Titlyanova, 2008)

Biotic turnover in larch forests in permafrost region of Northern Euroasia ? Carbon budget of larch forest at age 105 in northern taiga Local low-parametric dynamic model of Eastern Siberia (Permafrost ecosystems, 2010) of coupled carbon-nitrogen cycles with climatic parameterization and steady Carbon and nitrogen budgets of larch forests ( Larix gmelinii, states corresponding to larch forest or Larix cajanderi ) in forest tundra Enisey region in Eastern forest tundra ecosystem types Siberia (Forest ecosystems of the Enisey meridian, 2002) Photo from (Bazilevich and Titlyanova, 2008)

Universal scheme of a biotic turnover in terrestrial ecosystems Carbon and nitrogen flows in an ecosystem: G D+D’ Ph+Z photosynthesis, respiration, denitrification and nitrogen fixation consumption, Pr V+L+{ Slh } Mo+F+ Sph litterfall, excretion accumulation in real increment, import and export, abiotic oxidation, translocation Sln R Reservoirs : G – green phytomass, Pr – perennial phytomass, R – living roots, D + D’ - dead standing phytomass, V + L +{ Slh } – dead roots + litter + {humus}, Ph + Z – phyto- and zoophagues, Mo + F + Sph – microorganisms+fungi+saprophages, Sln – soil reserve nutrients.

Aggregation of biotic turnover schemes in terrestrial ecosystems G D+D’ Ph+Z V+L+{ Slh } Mo+F+ Sph Pr Sln R C C q 1 y 11 C y 12 C q 1 N y 1 G+Pr+R N N y 12 y 2 G+Pr+R C y 1 N q 2 C f 12 N N f 21 f 31 C q 2 Ph+Z+F+Mo N f 12 +Sph C f 12 N f 12 C C N y 2 f 13 f 13 C f 32 C C q 2 y 21 C q 3 N N f 32 f 23 N q 2 C N f 23 N q 3 y 21 D+D’+L+V+Sln D+D’+L+V+Sln C N y 31 y 32 C y 33 C y 32 C N y 32 y 31

Minimal aggregated compartment schemes of carbon and nitrogen cycles in tundra and forest tundra ecosystems Storages of carbon and nitrogen: C C q 1 y 1 NPP C 1 , N 1 - phytomass; N y 1 G+Pr+R C 2 , N 2 – phytophages and destructors N y 2 C 1 , N 1 (animals, fungi, bacteria); N q 2 C f 12 N C 3 , N 3 – dead organic matter of litter f 31 C y 2 Ph+Z+F+Mo+Sph and root-based soil layer N f 12 C 2 , N 2 C N f 13 f 13 C f 32 C q 3 N N f 32 f 23 D+D’+L+V C N f 23 q 3 C 3 , N 3 C N C y 31 y 31 y 32 Flows : q 1 C – carbon assimilation from the atmosphere, q 1 N , q 2 N – nitrogen input from adjacent ecosystems with atmospheric nitrogen fixation by microorganisms, q 3 C – dead organic matter input from adjacent ecosystems, y 1 C – autotrophic respiration, y 2 C – heterotrophic respiration, f 12 C , f 12 N – consumption of phytomass by phytophages, f 32 C , f 32 N – decay of dead organic matter by destructors with denitrification, f 23 C , f 23 N – death of destructors and phytophagues, y 31 C , y 31 N – export and run-off, y 32 C – abiotic oxidation of dead organic matter, f 31 N – nitrogen uptake by vegetation from soil, f 13 C , f 13 N – litterfall.

Two approaches to a dynamic model design by given «storage-flow» diagrams f ik (x i , x k ) dx q k ( t ) q i ( t ) Mass-balance equations: n x k ( t ) x i ( t ) i q y ( f f ) = − + − ∑ f ki ( x k , x i ) i i ki ik dt k 1 , k i = ≠ y k ( x k ) y i ( x i ) x 1 ( t ) q 1 ( t ) y 1 ( x 1 ) “Global” approach – started from (Svirezhev,1997) “Local” method 1) any number of static schemes for various 1) q * + f * = y * - at least one of the given time moments can be a source for a diagrams is a dynamic equilibrium; dynamic model; 2) y i = m i x i – output flows are linear; 2) y i = m i x i – output flows are linear; 3) q i = q i ( x i ), f ki = f ki ( x k , x i ); f ik = f ik ( x i , x k ) – 3) f ki = f ki ( x k , x i ); f ik = f ik ( x i , x k ) – flow functions flow functions are selected using biological are represented asymptotically near the given information and expert knowledge, e.g., equilibrium, : ~ x x x ∗ ij x - donor type, = − α i i i i - recipient type, ij x β ~ ~ ~ ~ ~ ~ ~ 2 2 f ( x x ) f x x x x x x ... j ∗ ∗ x x + = + α + β + γ + ξ + η + - Lotka-Volterra type, γ ij ij ij i ij j ij i j i i i j ij i j saturation types: ~ d x ~ ~ i x x ( ) ∑ ∑ = β − α + α − β + K x x K x x K x x i ji ij j ji ij dt ij i j ij i j ij i j j i j i , , ≠ ≠ ~ ~ ~ ( L x )( N x ) L x L x 2 + + ( ) x x x ( ) ... + + ∑ ∑ + γ − γ + ξ + η + ij j ij i ij j ij i ji ij i j j j j j i j i ≠ ≠

Modelling a combined carbon-nitrogen turnover in tundra ecosystems: biological mechanisms NPP Consumption Run-off LOM C 1 , N 1 LOM – living organic matter without consumers, Litterfall Consumption DOM – dead organic matter Decay Input Run-off DOM C 2 , N 2 Carbon and nitrogen interaction is provided by two mechanisms (Logofet, Alexandrov, 1984): 1) intensity of litterfall ( f 12 C ) is proportional to the C 1 / N 1 ratio in the living phytomass that reflects nitrogen starvation of plants; 2) decay rate for dead organic matter decreases with the increase of C 3 / N 3 ratio.

Modelling a combined carbon-nitrogen turnover in ecosystems: mathematical form NPP Consumption Run-off LOM C 1 , N 1 Litterfall Consumption Decay Input Run-off DOM C 2 , N 2 Mathematical form for coupled N-C потоков (Alexandrov et al., 1994): 1) Litterfall : 2 C N N C C f C - carbon flow: , nitrogen flow: f 1 = α = α 12 12 12 12 1 N 1 2) Decomposition of dead organic matter: 2 N C = N = N - carbon flow: , - nitrogen flow: C y d 2 y d N 21 2 21 2 2 C 2 2 N 3) nitrogen uptake from soil by plants: N N f 2 C = γ 21 21 1 C 2