Methane Emissions from the Stems of Living Trees in Upland Forests

Transcription

1 The 12th Interntionl Symposium on Biogeochemistry of Wetlnds in Corl Springs, Florid, USA, April 23-26, 218 Methne Emissions from the Stems of Living Trees in Uplnd Forests Zhi-Ping Wng Institute of Botny, Chinese Acdemy of Sciences, Beijing

2 Acknowledgements Pt Megonigl Sunith Pngl

3 Outline 1. Do plnt-bsed CH 4 emissions constitute distinct source? 2. CH 4 production / emissions in / from the hertwood / stems of living trees 3. Fctors controlling CH 4 production in hertwood 4. Perspective: Novel nd lrge source?

4 Are plnt-bsed CH 4 emissions distinct source? Aerobic CH 4 Hygrophyte CH 4 Hertwood CH 4 Downwood CH 4 Trnsport CH 4 Crmichel et l. 214

5 Plnt-bsed emission of Tg CH 4 yr 1 (Crmichel et l., 214)? Globl emission of 645 Tg CH 4 yr 1 (Schlesinger & Bernhrdt, 213) Tree stem-bsed emission?

6 Forest Wetlnds versus Uplnd Forests 5% Are 95% CH 4 CH 4

7 Uplnd Forests

8 Outline 2. CH 4 production / emissions in / from the hertwood / stems of living trees Hertwood Stem

9 () Upper plot Lower plot Mountin Hedqurter (b) G 19 Mountin Well Pck-wy N (c) (d) Stem chmber Twig chmber Ground chmber The experimentl lyout in the Beijing Forest Ecosystem Sttion (), the upper plot (b), the lower plot (c), nd chmbers (d).

10 July 214 July 215 Spring Summer Autumn Winter

11 Trunk CH 4 emission (μg m 2 h 1 ) Upper plot Lower plot 3 Air 5 cm 2 15 cm July December 214 Jnury July Temperture ( o C) CH 4 Groundwter Root distribution -4cm

12 Soil depth (cm) CH 4 concentrtion (1 4 μl L 1 ) Mteril CH 4 concentrtion (μl L 1 ) (b) e e e e e P. dvidin C. cthyensis Brk Spwood Hertwood b c d P. dvidin e b c d C. cthyensis e,f f e,f f () Poplr tree

13 CH 4 production (ng gdw 1 h 1 ) CH 4 production (ng gdw 1 h 1 ) CH 4 oxidtion (ng gdw 1 h 1 ) Aerobic n.. n.. n.. n.. n.. n.. Brk Spwood Hertwood P. dvidin C. cthyensis Anerobic P. dvidin C. cthyensis P. dvidin C. cthyensis S, 4cm S, 8cm S, 12cm R, 4cm R, 8cm Mteril Brk Spwood Hertwood Anerobic () (b) (c)

14 CH 4 production in the hertwoods of living P. dvidin in smll terrce in the Xiolongmen Forest Frm. Position Averge Trunk dimeter ge (y) (cm) Wter content CH 4 concentrtion CH 4 production (%) (μl L 1 ) (ng gdw 1 h 1 ) '6.8"E, 31 57'3.5"N (5.7) 68.5 (3.) 23.6 (2.) (63.9) 115 m bove se level Vlue is Men (SD), n = 5 for trunks. Wood mterils were smpled in August 9, 215. Hertwood

15 Previous studies Our study CH 4 CH 4

16 Trunk CH4 emission (μg m 2 h 1 ) cm cm cm cm Jul 214 Aug Sep Oct Nov Mr 215 Month Apr My Jun Jul

17 CH 4 flux clcultions nd CH 4 budget estimtes Tble 1 Annul budget of CH 4 in the forest ecosystem Component Jul 214 Aug Sep Oct Nov Dec Jn 215 Feb Mr Apr My Jun Jul Annul Tree Populus dvidin Trunk I n Trunk II Trunk III Twig nd lef n.. n.. Cry cthyensis n.. n.. n.. n.. Lrix gmelinii n.. n.. n.. n.. Soil Plot-wide CH 4 (g plot 1 ) Tree Men Rnge 7.3~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~43.3 Soil Plot-wide CH 4 were estimted using the prmeters of living tree species, such s the 84 trunks of living P. dvidin in the lower plot of 16 m 2 (Tree bses were ssumed s zero nd not excluded in plot re) nd the men 15.3 m trunk height of P. dvidin (see Tble S1). Trunk I, II, nd III indicte trunk CH 4 emissions clculted by rithmetic verge, logrithm function, nd power function, respectively. Annul CH 4 is the sum of those in months; CH 4 in July is n verge of two vlues in July 214 nd July 215. The CH 4 fluxes mesured were undetectble nd defined s n.. for not pplicble (no dt vilble). CH 4 flux (μg trunk 1 h 1 for tree or μg m 2 h 1 for soil)

18 Trditionl hypothesis Our result 1% 37% CH 4 CH 4 63% Almost pure poplr forest 1% 1%

19 Outline 3. Fctors controlling CH 4 production in hertwood Tree species with cpcity of substntil CH 4 production in hertwood Temperture Wter content (Wng et l., 217, Journl of Geophysicl Reserch: Biogeosciences) Most of tree species with no cpcity of substntil CH 4 production in hertwood (Wng et l., 217) Even if high wter content, no CH 4 production! Why? Secondry metbolites, e.g. crbohydrtes, phenolic compounds? (Unpublished)

20 Field investigtion N Chngbishn Beijing Midtemperte Shennongji 2 2 m 2 plots Increment borer Sub-tropicl Wrm temperte

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22 Proportion of tree species (%) Proportion of tree stems (%) 1 The rnges: R1 < 21.6; 21.6 R2 < 1; 1 R3 < 1,; 1, R4 < 1,; nd R5 1, μl L b Mid-temperte Sub-tropicl Wrm temperte R1 R2 R3 R4 R5 Mid-temperte Sub-tropicl R1 R2 R3 R4 R5 Wrm temperte The rnge of hertwood CH 4 concentrtion b () 4 13% (b) 8 31% The rnges: R1 < R2 < 1 1 R3 < 1, 1, R4 < 1, R5 1, μl L 1 CH 4 emission?

23 Stem CH 4 emission (μg m 2 h 1 ) U M L () 15 Jul 17 Jul 29 Aug 2 Aug 14 Aug 24 Sep 2 Sep 11 Sep 22 Oct 5 Oct 22 Hertwood CH 4 concentrtion (1 4 μl L 1 ) On sesonl scle Jul 17 Jul 29 Aug 2 Aug 14 Aug 24 Sep 2 Sep 11 Sep 22 Oct 5 Oct 22 Time Methne concentrtion Wter content (b) Hertwood wter content (v/v, %)

24 Hertwood CH 4 concentrtion (1 4 μl L 1 ) 36 3 Mid-temperte () y = 2E-61x R²= Sub-tropicl y = 1E-58x R²=.6856 (c) 4 3 Wrm temperte (b) y = 9E-6x R²=.9675 Assumed threshold Hertwood wter content (w/w, %)

25 Extrctive solution of hertwood of tree species tht hs no cpcity of substntil CH 4 production in hertwood Adding Answering why no cpcity of substntil CH 4 production Fresh hertwood of nother tree species tht hs the cpcity of substntil CH 4 production in hertwood

26 CH 4 production (ng gdw 1 h 1 ) 1 8 () 6 4 b U. dvidin + DW A A U. dvidin + Extrctive Hertwood + DW Hertwood + Extrctive U. dvidin P. cndensis Tretment U. dvidin + utoclved Extrctive Wter-soluble extrctives enhnced microbil CH 4 production. () Tretments re the 1 g hertwood of Ulmus dvidin + 1 ml Deionized Wter, + Extrctive (1 ml hertwood extrctive solution of Slix mtsudn (no CH 4 production)) nd + utoclved Extrctive. (b) Tretments re the 1 g hertwood of U. dvidin or P. cndensis + 1 ml DW nd + 1 ml hertwood extrctive solution of P. tbuliformis (no CH 4 production). b (b)

27 CH 4 production (ng gdw 1 h 1 ) b P. dvidin + DW P. dvidin + extrctives Tretment Ethnol-soluble extrctives enhnced microbil CH 4 production, when ethnol s effect ws removed. Tretments re the.8 g fresh hertwood of Populus dvidin + 1 ml DW nd + 1 ml 1% E extrctive solution of Pinus tbuliformis (no CH 4 production) evported nd then 1 ml DW dded.

28 CH 4 production (ng gdw 1 h 1 ) 3 24 Hertwood + DW Hertwood + Extrctive b b b P. cndensis U. dvidin P. dvidin Tretment Acetone-soluble extrctives inhibited microbil CH 4 production, when cetone s effect ws removed. Tretments were the 1 g fresh hertwood of P. cndensis or U. dvidin + 1 ml DW or 1 ml hertwood extrctive solution of P. tbuliformis (no CH 4 production), the 1 g fresh hertwood of P. dvidin + 1 ml DW or + 1 ml hertwood extrctive solution of S. mtsudn (no CH 4 production).

29 No substntil CH 4 in the hertwood of most tree species in uplnd forests, when other vribles re pproprite Net effect of secondry metbolites on microbil CH 4 production in hertwood? Inhibition!

30 Summry For tree species with cpcity of substntil CH 4 production, when temperture ws not limiting fctor for CH 4 production in summer nd utumn, nd thus, most of the CH 4 production my be explined by wter content in the hertwood of living trees. For tree species with no cpcity of substntil CH 4 production, net effect of secondry metbolites my inhibit microbil CH 4 production in the hertwood.

31 Perspective: Novel nd lrge source? 1, Ecogeogrphy: temporl nd sptil distribution, the mgnitude of CH 4 emission? 2, CH 4 production mechnism nd dynmics? 3, More reltionships between CH 4 production/emission nd fctors?

32 Thnk you for ttention