THE RESULTS OF THE COMPREHENSIVE STUDY OF SIBERIAN SPRUCE SEEDLINGS - PowerPoint PPT Presentation

THE RESULTS OF THE COMPREHENSIVE STUDY OF SIBERIAN SPRUCE SEEDLINGS RESPONSE TO UV-B RADIATION EXPOSURE Е.М. Korotkova 1 , V.V. Zuev 1,2,3 , N.E. Zueva 1 , O.G. Bender 1 , A.V. Pavlinsky 1 , V.L. Pravdin 1 1 Institute of Monitoring of Climatic and Ecological Systems, Tomsk, Russia 2 Tomsk State University, Tomsk, Russia 3 Tomsk Polytechnic University, Tomsk, Russia ENVIROMIS-2016 11-16 July 2016 , Tomsk

UV-B radiation as a factor of mountain forests drying - UV-B radiation is a reason of plant stress, photosynthesis degradation and growth inhibition; - Forest drying is a complex process, including climatic, biotic and anthropogenic factors; The main goal: - Quantity of UV-B radiation depends on ozonosphere conditions; - There is lower ozone content above the mountain territories; Estimation of the role of the UV-B radiation in forest - Thus, drying of conifer forests of South Siberia mountains can be associated drying of South Siberia mountains with UV-B radiation. Ozone depletion above the South Siberia mountains Forest drying in the mountains of South Siberia is observed at: Kuznetskiy Alatau East Sayan - Kuznetskiy Alatau; Khamar-Daban West Sayan - West Sayan; - East Sayan; - Khamar-Daban.

Experiment as a decision The aim of the present study: To investigate the effect of additional UV-B radiation exposure on the state of conifers using not only biological, but ecological approach We are interested in: - Vital status of the plants - Photosynthesis and transpiration changes - Soil moisture changes (evaporation, consumption by plants)

About experiment The experiment was carried out on spruce seedlings during the period from June to August of 2015. The test plants were divided into two groups: one experimental and one control group. The seedlings were planted in plastic containers and placed in the experimental room with access for the background solar radiation and natural ventilation. The experimental group of plants was exposed to UV-B radiation at a wavelength of 308 nm for 4 hours daily. The plants received daily a dose of additional ultraviolet radiation comparable to a 30% deficit of ozone in the atmosphere for Tomsk. Both groups of plants were further exposed to photosynthetically active radiation from fluorescent phytolamps.

Experiment Experiment design Measurments: - Photosynthesis of the 1- and 2- Timer year old needle; - Transpiration of the 1- and 2-year UVB-308 old needle; Lamp PAR Lamps - Needle water content; - Chlorophyll fluorescence response; - Soil moisture. Air temperature, humidity and Soil Emitter/fluor. signal other weather conditions were also hygrometer receiver fixed. Gas analyzer

Photosynthesis, transpiration, needle water content Photosynthesis rate : Needles: 1-year old, cont 1-year old, exp 1,4 -1 1- and 2-year-old needles in -2 s 2-year old, cont CO 2 absorbtion, mkmol m 1,2 2-year old, exp the experimental group - 28% 1,0 and 40% lower than that in the 0,8 0,6 control group. 0,4 0,2 0 10 20 30 40 50 60 70 80 90 100 Transpiration rate: 0,6 -1 -2 s 1- and 2-year-old needles in H 2 O excretion, mkmol m 0,5 the experimental group - 16% 0,4 and 33% lower than that in the 0,3 0,2 control group. 0,1 0 10 20 30 40 50 60 70 80 90 100 76 72 Needle water content, % Needle water content: 68 64 No significant changes. 60 56 52 0 10 20 30 40 50 60 70 80 90 100 Day

Soil moisture drying and air parameters dynamics control control experiment experiment 3,0 soil 2,5 Soil drying velocity, %/day 2,4 2,5 2,3 2,2 2,0 Soil drying velocity, %/day 2,1 1,5 2,0 1,9 Air temperature 30 70 Air humidity 1,8 29 65 28 1,7 Air temperature, ° C 60 27 Air humidity, % 1,6 26 55 25 1,5 50 24 1,4 45 23 22 40 1,3 21 35 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 Day Day

The results of the fluorescence response study Control 1,06 Experiment 1,04 1,02 1,00 685/740 nm, rel. units. 0,98 0,96 0,94 0,92 0,90 0,88 0,86 10 20 30 40 50 60 70 80 Day The chlorophyll fluorescence response in the experimental plant group showed the behavior opposite to normal response of the control plant group, revealing photosynthesis degradation and plant stress.

Ozonosphere behavior analysis Ozone normals 1979-1991 and 1992-2012 differences (active Pinatubo Ozone ( V-VIII) vegetation period V-VIII) Average 360 350 Kuznetskiy Alatau Ozone, D. u. 344 340 East Sayan Khamar-Daban 331 330 West Sayan 320 1976 1980 1984 1988 1992 1996 2000 2004 2008 2012 Years Negative deviations of ozone from normal, The increase of Territory % intensity of conifer forests drying process 1979-1991 гг . 1992-2012 гг . in South Siberia Kuzneckiy Alatau 20 74 mountains is registered West Sayan 16 76 since the second half of 1990-s. East Sayan 13 75 Khamar-Daban 13 76

Summary - The experiment showed the negative impact of UV-B radiation on photosynthesis and its decrease in the needles of different ages. Chlorophyll fluorescence response also reveals the changes in the photosynthetic apparatus in the experimental plant group. The additional UV-B radiation exposure led to an increase in water consumption from the soil, reducing the level of soil moisture available to plants. Thus, the set of adverse effects due to an extra dose of UV - B radiation exposure, can be manifested not only directly, resulting in the weakening by inhibiting photosynthesis and growth, but also indirectly, i.e. creating a moisture deficit in the soil, due to increased water consumption. - Actually, the increase of intensity of conifer forests drying process in South Siberia mountains since the second half of 1990-s is observed against a backdrop of ozone depletion from 1992.

THANK YOU FOR ATTENTION! Е.М. Korotkova 1 , V.V. Zuev 1,2,3 , N.E. Zueva 1 , O.G. Bender 1 , A.V. Pavlinsky 1 , V.L. Pravdin 1 ENVIROMIS-2016 11-16 July 2016 , Tomsk