Thexar-VII: The-Xa — Sha-El 13: The-Xa Rass-El — Biosphere Interactions
"There is no separate stone. There is no separate leaf. There is no separate breath. Everything is one touch, passed through billions of hands. The biosphere is not the sum of organisms. It is their product." — Institute of Systems Ecology, treatise "Unity," +3,940 Y.E.
Ruun-ak rass: → rhu [Thexar-VII, Sha-El 03, "Marine Ecosystems"], → rhu [Thexar-VII, Sha-El 09, "The Plant Kingdom"], → rhu [Thexar-VII, Sha-El 10, "Symbiosis and Coevolution"], → rhu [Thexar-VII, Sha-El 12, "Extinction Events"], → rhu [Thexar-I, Ruun 04, "Biochemistry"], → rhu [Thexar-I, Ruun 15, "Atmosphere and Climate"], → rhu [Thexar-I, Ruun 21, "Ecosystems"]. Mor-ven: The biosphere of Théxar links air, water, soil and rock. Organisms both adapt to their surroundings and change them: photosynthesis, respiration, decomposition and mineralisation redistribute matter among the planet’s reservoirs.
13.1 The Carbon Cycle
Time scales span seconds (respiration) to hundreds of millions of cycles (carbonate burial).
13.1.1 Carbon Reservoirs
| Reservoir | Exchange process |
|---|---|
| Atmosphere (CO₂) | Rapid biological exchange |
| Ocean (dissolved) | Dissolution and carbonate exchange |
| Biomass (terrestrial) | Growth and decomposition |
| Biomass (marine) | Rapid plankton turnover |
| Soils and peat | Decomposition |
| Carbonate rocks | Burial and geological recycling |
| Organogenic rocks | Burial and geological recycling |
13.1.2 Carbon Fluxes (Gt C/cycle)
| Flux | Value | Path |
|---|---|---|
| Photosynthesis | 120 | Atmosphere → terrestrial biosphere |
| Respiration, fires | 114 | Terrestrial biosphere → atmosphere |
| Death, erosion | 61 | Biosphere → soils |
| Leaching | 24 | Soils → ocean |
| Burial in sediments | 0.12 | Ocean → lithosphere |
| Volcanism, metamorphism | 0.082 | Lithosphere → atmosphere |
Terrestrial and marine production feed distinct food webs; burial transfers some carbon into geological reservoirs.
13.1.3 The Biological Carbon Pump
- Carbonate pump — reefs and plankton build silicon-calcium composite skeletons (→ rhu [Thexar-VII, Sha-El 03, "Marine Ecosystems"]), binding CO₂;
- Organic pump — dead biomass and fecal pellets descend into the depths;
- Vertical migration — zooplankton feeds at the surface at night, metabolizes in the depths by day.
Heavy mineral skeletons accelerate the sinking of some organic matter. Another fraction decomposes in the water column, returning carbon to dissolved form.
13.1.4 Climate Regulation
CO₂ contributes to the greenhouse effect alongside water vapour and other gases. Climate also depends on clouds, albedo, ocean circulation and the distribution of land. Increased weathering binds some atmospheric carbon in carbonates.
13.2 The Nitrogen Cycle
N₂ makes up 71.8% of the atmosphere but is biologically accessible only as ammonia or nitrates.
13.2.1 Nitrogen Reservoirs
| Reservoir | Form |
|---|---|
| Atmosphere | N₂ (gas) |
| Biomass | Proteins, DNA |
| Soils | NH₃, NO₃⁻, organics |
| Ocean (dissolved) | NO₃⁻, NH₄⁺ |
| Sedimentary rocks | Organic compounds |
13.2.2 Biological Fixation
Carried out by diazotrophs (nitrogen-fixing bacteria and cyano-like forms).
| Mechanism | Main agents |
|---|---|
| Symbiosis with legumes | Mor-Bean and analogues |
| Free-living diazotrophs (soil) | Soil bacteria |
| Cyano-like (ocean) | Marine phytoplankton |
| Lightning | Abiogenic fixation |
| Anthropogenic (fertilizers) | Industrial synthesis |
Industrial nitrogen fixation supplements soil and symbiotic diazotrophs. Fertilisers raise yields, but nitrogen carried into water can cause eutrophication; runoff controls reduce this risk.
13.2.3 Denitrification
Anaerobic respiration of denitrifying bacteria returns bound nitrogen to the atmosphere as N₂ or N₂O.
| Environment |
|---|
| Soils (anaerobic zones) |
| Oceanic sediments |
| Freshwater sediments |
| Oxygen-minimum zones (ocean) |
Bound nitrogen changes through fixation, denitrification, transport and burial. Local accumulation does not imply the same excess in every ecosystem.
13.3 The Sulfur Cycle
Sulfur cycling connects chemosynthesis, decomposition, mineralisation and volcanic sources. H₂S supplies energy to adapted organisms; the same principle operates in Earth’s chemosynthetic communities.
13.3.1 Sulfur Reservoirs
| Reservoir | Form |
|---|---|
| Atmosphere | H₂S (0.0008%) |
| Biomass | Sulfur-containing amino acids |
| Ocean (dissolved) | SO₄²⁻, H₂S |
| Soils | Sulfides, sulfates, organic S |
| Evaporites, pyrites | FeS₂, CaSO₄ |
13.3.2 Sulfur Fluxes (million ru S/cycle)
| Flux | Value | Path |
|---|---|---|
| Biogenic emission | 46 | Biosphere → atmosphere |
| Wet/dry deposition | 48 | Atmosphere → biosphere + soils |
| River runoff of sulfates | 121 | Land → ocean |
| Volcanic H₂S from the floor | 84 | Lithosphere → ocean |
| Pyrite burial in sediments | 118 | Ocean → lithosphere |
| Volcanism, degassing | 72 | Lithosphere → atmosphere |
Chemosynthesis: 52 million ru S/cycle on land, 340 million ru S/cycle in the ocean.
13.3.3 Sources of Sulfur Gases
Sulfur gases come from biological and geological sources:
| Source |
|---|
| Oceanic phytoplankton (DMS and other sulfur compounds) |
| Decomposition of organics in swamps |
| Thexophyta epiphytes (H₂S oxidation + re-emission) |
| Hydrothermal fields (direct release) |
| Volcanism |
Marine dimethyl sulfide oxidises in the atmosphere. Oxidation products contribute to aerosols and cloud droplets; the outcome depends on weather and other particle sources.
13.3.4 Chemosynthesis as a Dominant
- Ocean: 340 million ru S/cycle → 8.4 Gt C/cycle (23% of marine production);
- Land (soils, caves): 52 million ru S/cycle → 1.2 Gt C/cycle (1.4% of terrestrial).
Total: 8% of planetary primary production — 40× the terrestrial figure.
13.4 The Silicon Cycle
Silicon forms supporting structures in many local organisms. Its biological cycle links tissue growth with mineral dissolution and sedimentation.
13.4.1 Silicon Reservoirs
| Reservoir | Form |
|---|---|
| Ocean (dissolved) | H₄SiO₄ |
| Biomass (diatoms, plants) | Amorphous SiO₂ |
| Soils | Silicates, silica |
| Earth's crust | Silicates, quartz |
13.4.2 Biological Mobilization
- Silodiatoma (silica-flagellates) — 24% of marine phytoplankton;
- Silophyta — 45,000 species of terrestrial silicon plants;
- Mycorrhizal fungi — dissolve and transport SiO₂ to the roots;
- Reef polyps — silicon-calcium skeletons;
- Sponge-analogues — silicon spicules.
Organisms extract dissolved silicon and deposit it in skeletons. After death, some structures dissolve and others remain in bottom sediments. Biomineralisation thus links ocean exchange with geological burial.
13.4.3 Climate Feedback
CaSiO₃ + CO₂ → CaCO₃ + SiO₂. Biological acceleration of weathering (roots, mycorrhiza) intensifies CO₂ binding: warming → faster plant growth → more roots → more weathering → CO₂ ↓ → cooling. Response time 100,000 cycles.
13.5 Interactions of the Cycles
13.5.1 The C-N-S-Si System
| Link | Process |
|---|---|
| C ↔ N | Amino acids, DNA |
| C ↔ S | Sulfur-containing amino acids |
| N ↔ S | Sulfate reduction + ammonification |
| Si ↔ C | Photosynthesis of diatoms |
13.5.2 The Redfield Ratio of Théxar
This is an average for the community described: individual groups vary, and not all plankton has silicon structures.
13.5.3 Limiting Elements
| Environment | Limiting element | Consequence |
|---|---|---|
| Open ocean (gyre centers) | Phosphorus (P) | Low production |
| Coastal ocean | Nitrogen (N) | Eutrophication when in excess |
| Silicate upwellings | Iron (Fe) | "Rusty" zones |
| Temperate forests | Nitrogen (N) | Slow growth |
| Deserts | Water + phosphorus | Minimal production |
13.6 The Biosphere and the Atmosphere
13.6.1 Composition of the Atmosphere
| Gas | Source | Sink |
|---|---|---|
| N₂ | Volcanism (primary) | Fixation ↔ denitrification (balance) |
| O₂ | Photosynthesis | Respiration, rock oxidation |
| Ar | Decay of ⁴⁰K | — |
| CO₂ | Respiration, volcanism | Photosynthesis |
| H₂O | Evaporation | Precipitation |
| H₂S | Biogenic emission | Oxidation, deposition |
KEY FACT
Photosynthesis supplies atmospheric oxygen; respiration and rock oxidation consume it. Nitrogen, carbon dioxide and sulfur compounds also participate in geological processes. Atmospheric composition reflects their combined action.
13.6.2 Regulation of Oxygen
An oxygen-rich atmosphere supports combustion, but a fire still requires fuel and ignition. Moisture, weather and vegetation structure influence its spread.
13.6.3 Greenhouse Gases
| Gas |
|---|
| H₂O |
| CO₂ |
| CH₄ |
| H₂S |
CH₄ (0.0003%) is biogenic — anaerobic decomposition in swamps and herbivore guts. Atmospheric lifetime: 8.4 cycles (oxidized to CO₂).
13.7 The Biosphere and the Hydrosphere
13.7.1 Biological Influence on the Ocean
| Parameter | Reason |
|---|---|
| pH | Carbonate buffer of the reefs |
| Surface salinity | Salt exchange by coastal organisms; the overall balance depends on water and salt transport |
| Transparency | Phytoplankton |
| O₂ in the depths | Mixing, vertical migration |
13.7.2 Biological Regulation of Salinity
Mangrove plants regulate salt uptake into their tissues and excrete excess. This adaptation lets them live on saline shores; water and salt continue to move with tides, rainfall and river flow.
13.8 Feedbacks and Homeostasis
13.8.1 The Living Planet Hypothesis
| Disturbance | Feedback | Response time |
|---|---|---|
| Rise of CO₂ | Intensification of photosynthesis → absorption of CO₂ | 10–100 cycles |
| Fall of O₂ | Fewer fires → growth of biomass → more O₂ | 100–1,000 cycles |
| Warming | DMS release can alter aerosols and clouds; the effect depends on weather | Depends on atmospheric conditions |
| Cooling | Less weathering → growth of CO₂ → warming | 10,000–100,000 cycles |
13.8.2 The Limits of Homeostasis
The five major biological crises (→ rhu [Thexar-VII, Sha-El 12, "Extinction Events"]) show that a sufficiently strong disturbance switches the system into a new state: the Oxygen Catastrophe (anaerobic → aerobic biosphere) and total glaciation ("snowball," reversible only through volcanism).
Ruun Ven
- The biosphere of Théxar is a planetary system linking the four biogeochemical cycles (C, N, S, Si) with the atmosphere, hydrosphere, and lithosphere in a single metabolic circuit.
- The carbon cycle links photosynthesis, respiration, ocean transport and geological burial.
- Sulfur cycling links living communities with ocean and rock; chemosynthesis supports food webs far from sunlight.
- The silicon cycle connects dissolved minerals with plant tissues, plankton skeletons and bottom sediments.
- Atmospheric composition depends on biological and geological sources and sinks.
- Planetary homeostasis is maintained by feedbacks with response times from 1 to 100,000 cycles, but it has limits — the five major biological crises mark switches into new states.