Acid deposition, soil pollution and plant growth: current status and future forest ecosystems

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1 IPiCEX 2008 Acid deposition, soil pollution and plant growth: current status and future forest ecosystems Sase, H, Ohizumi, T, Nakayama, S, Leong CP, & Ueda H. Network Center for EANET, Acid Deposition and Oxidant Research Center Introduction Acid Deposition Monitoring Network in East Asia (EANET): started regular-phase activities in 2001 Periodic Report on the State of Acid Deposition in East Asia: published by the Scientific Advisory Committee of EANET in 2007 No clear evidence of the impacts on forest ecosystems was reported in the periodic report. However, several abnormal phenomena have been reported recently. Possible impacts of acid deposition/air pollution on forest ecosystems in Japan and the East Asian region will be discussed in this presentation. 1

2 Acid deposition surveys in Japan Japan Acid Deposition Surveys (JADS) by the Ministry of the Environment of Japan (MOEJ): since 1983 (not 1883 ) (Local) acid deposition surveys by Japan Environmental Laboratories Association (JELA): since The wet deposition data collected by the wet- only precipitation samplers are available for more than 0 sites in Japan. Deposition amounts of non sea salt (nss-) ) SO 2-4 (n=120, ) Nagaoka Deposition Ijira Concentration Precipitation 4 2

3 Deposition amounts of NO - 3 (n=120, ) Nagaoka Deposition Ijira Concentration Precipitation 5 Deposition amounts of NH + 4 (n=120, ) Nagaoka Deposition Ijira Concentration Precipitation 6 3

4 Deposition amounts of H + (n=120, ) Nagaoka Deposition Ijira Concentration Precipitation 7 Seasonal changes in deposition amounts in a forest near the Sea of Japan (near( Nagaoka) Rainfall outside the canopy TF + SF Deposition amounts increased in winter due to effects of seasonal winds from the west (Kamisako, Sase et al., 2008). 4

5 Annual mean concentration, 0.1gN L -1 Concentration Comparison with Europe and US EMEP (N=81) NADP (N=254) Japan (N=82) N Nagaoka 25 Ijira Precipitation amount, mm y Wet deposition, kgn ha -1 y -1 Annual mean concentration, 0.1gS L Precipitation EMEP (N=81) NADP (N=254) nss-s Nagaoka 25 Japan (N=81) Ijira Precipitation amount, mm y -1 Nagaoka: 19 kgn ha -1 y -1 and 18 kgs ha -1 y -1 Ijira: 17 kgn ha -1 y -1 and 18 kgs ha -1 y -1 Japan can be characterized as having higher acid loading Wet deposition, kgn ha -1 y -1 Deposition Comparison with the EANET data Weishuiyuan,, a rural site of China: 20.9 kgn and 54.1 kgs Guanyinqiao,, an urban site in Chongqing of China: 29.7 kgn and 52.4 kgs Petaling Jaya an urban site of Malaysia: 25.3 kgn and 20.9 kgs Depositions of nitrogen and nss-sulfur sulfur in East Asia, especially in big cities and their surrounding areas, may be significantly larger than those in Europe and the United States. 5

6 Soil acidification at the Lake Ijira Catchment, Japan-1 ph(h2o) a)suface soil ph(h 2 O) Plot 37 Plot 38 Plot 41 Plot 46 Plot b)subsoil ph(h 2 O) Plot 37 Plot 38 Plot 41 Plot 46 Plot Soil acidification at the Lake Ijira Catchment, Japan-2 cmol(+) kg c)surface soil, Ex-Al Plot 37 Plot 38 Plot 41 Plot 46 Plot d)subsoil, Ex-Al Plot 37 Plot 38 Plot 41 Plot 46 Plot

7 Natural, forest management, or acid deposition? Soil acidification may be induced by rapid plant growth, especially in plantations. However, the growth rate 20 (basal area index: BAI) gradually decreased 15 during the monitoring period from Soil acidification at the 5 Ijira Catchment may be attributed mainly to the 0 high acid loading. BAI, cm 2 tree -1 y -1 C. japonica C. obtusa Effects of soil acidification? Effects on tree health were not clear at the Lake Ijira Catchment. However, river and lake waters have been acidified since the mid-1990s in the Lake Ijira catchment (Yamada et al., 2007). Acid neutralizing capacity (ANC) of soil and geology may be related to river water acidification. In Niigata (e.g. Nagaoka) and Gifu (e.g. Ijira), which suffer the highest level of acid deposition, the decreasing trends of river water ph have been identified to be in catchments dominated by acidic rocks, such as granite and rhyolite (Matsubara, Morimoto, Sase et al., 2008) 7

8 Bedrock geology of Niigata Pref. (K) (J) (C) Granite Andesite Limestone 15 Long-term term trends of river water ph in Niigata from 1986 to 2003 Area River name Sampling point n Zscore K Omata River k * K Miomote River k ** Ara River k *** k *** k *** k *** Tainai River k k * k Agano River k k k k k *** k *** Araya River k *** Tokonami River k *** C Ikarashi River c C Aburuma River c Sanashi River c Saguri River c Uono River c Kiyotsu River c ** c Nakatsu River c *** c *** J Yashiro River j J Sibue River j ** Seki River j j *** Nou River j Hayakawa River j Himekawa River j j *=p<0.05 ** =p<0.01 *** =p<0.001 ph decline: 11sites ph increase : 5sites All sites where the declining trend was observed are located in area (K). ph Zscore= p=9.2e-04 K

9 % of declined trees Current condition of the EANET forest monitoring site Jinyunshan No.1 Jinyunshan No.2 natural factors unknown factors insect or disease cn jp ph kr ru th Dabagou XPZ-01 XPZ-02 XPZ-03 XPZ-04 Zhuxiandong No.1 Zhuxiandong No 2 Zhuxiandong No 3 Lake Ijira Yamato Banryu Iwami-rinku FP Mt. Makilling UP Quezon-Land Grant Mt. Naejang Bolshie Koty Irkutsk Mondy Vachiralongkorn Puye Vachiralongkorn Dam No clear evidence of acid deposition/air pollution (EANET, 2007) Tree decline at Mt. Bogdkhan, Mongolia A1 Thermal Power plant No.3 B A2 C D RF1 RF2 Bogdkhan Mountain 1km 9

10 Site B Boundary area between grassland and forest SO2 (ppbv) a) Air concentrations and S contents of larch (Larix sibirica) ) needles at Mt. Bogdkhan Two-week week mean by passive samplers O3 (ppbv) b) SO 2 ac a O 3 a b bc c bc d a b ac c mg-s/g-dry needles S contents of larch needles A B C RF1 RF2 Site Larger effects at the slope facing the thermal power plant, site B and C (Sase et al. 2005; EANET,2006) A1 A2 B C RF1 RF2 Site

11 Severe air pollution in Ulaanbaatar City in winter The Ulaanbaatar City is located in a basin surrounded by mountains. In winter, many people come back to the basin and live in the mobile house, Ger,, around the City. Coal combustion in the ger and thermal power plants causes severe air pollution in the Ulaanbaatar City, especially in winter. Effects on forests in the mountains should be investigated furthermore. Decline of Japanese cedar (Cryptomeria( japonica) and oxidants index in Kanto Plain, Japan OI, oxidants index: accumulated hours, whose oxidants concentration was over 0.06 ppm from May to September (Takahashi et al., 1987) 11

12 IPICEX 2008 Epicuticular wax structure of C. japonica leaves-1 Clear crystal structure of 0-y leaves in Spring 23 Epicuticular wax structure of C. japonica leaves-2 A stoma of 0-y leaves in Spring 24 12

13 IPICEX 2008 Epicuticular wax structure of C. japonica leaves-3 Destroyed crystals of 0-y leaves in late autumn 25 Enhanced wax production and erosion in the plain area Erosion rate rate Approx. 30% Approx. 20% Wax erosion is faster in the plain (declining) area, even if the initial production was stimulated (Sase et al., 1998). 13

14 Wax amount and cuticular transpiration rate Not only wax amounts but also other factors may accelerate the water loss (Sase et al., 1998). Particulate matters trapped at the stomata Stomata clogged by particulate matters could be seen in 1-y 1 y leaves. Takamatsu, Sase, & Takada

15 Malfunction of the stomata A: collected in the mountainous area (The dye was stopped at the stomata) B: collected in the plain area (The dye was leaked even after abscisic acid treatment ) Water loss from the leaves may be accelerated. (Sase & Takamatsu, in press) Dry condition enhanced the water loss (Sase et al., 1998) 15

16 High ozone concentration in Nikko Mountainous Area (Ministry of the Environment, Japan) High ozone concentration in East Asia Ozone concentration is increasing year by year in several countries. High ozone concentration was recorded also in forest area,, for example in Sakaerat SRS Thailand b v, p 40 O day mean by Passive samplers O3 NH3 NO v p b, O 2 N & H 3 N 16

17 Conclusion-1 Amount of acid deposition in the East Asian region is quite large compared with Europe and the United States. So far, effects of acid deposition/air pollution on forest ecosystems have not been apparent on the regional level. However, evidence showing soil acidification, river water acidification, and tree decline has been reported in several sensitive areas recently. Emission of nitrogen and sulfur is still increasing annually. Conclusion-2 In regions with sensitive geology and high acid loading,, impacts of acid deposition may become obvious. Identification of such hot spots and long-term and comprehensive monitoring on soil, forest vegetation, and streams/rivers may be important for the conservation of forest ecosystems. Synergistic effects by acid deposition and other factors including meteorological events and forest management should also be considered. 17