Morphology and photosynthesis of Larix sibirica needle in Ural region Zagirova Svetlana Institute Biology Komi SC URB RAS

Afforested areas in Komi Republic: 1- spruce, 2- pine, 3- fir, 4- larch, 5- cedar, 6- birch, 7- aspen, 8- others

The investigations were carried out in western mountainside of the Northern and Sub-Polar Ural (Pechora-Ilych reserve, National park “Yugyd Va”)

Larch stands on the Northern and Sub-Polar Ural

Larch trees at altitude timber line of Sub-Polar Ural

Morphology of larch stand at altitude timber line on the Northern Ural of plot Altitude, m a.s.l. Stand composition, % Age of trees Average value of Number of trees/ 1 he height, m diameter, cm 1 623 90 Larix 10 Betula In total 61-135 32-109 6.5 3.4 20 6.9 144 200 344 2 550 80 Larix 20 Betula Single Abies 78-110 40-100 -* 6.6 4.5 3.8 20.9 10.2 9.0 456 556 22 1034 3 540 70 Larix 10 Abies 71-248 43-100 47-137 9.6 4.9 4.3 28.2 10.9 10 133 400 378 911 4 502 60 Abies 20 Larix Singl Cedar 89-130 - 34-88 41-240 5.1 7.7 5.3 5.7 11.9 28.6 12.5 14.0 1167 78 289 1556 Примечание. * - нет данных

The objects of investigation Methods and instruments Morphologic structure of larch needles Light and electronic microscope methods Structure of photosynthetic tissue and cells in needles Photosynthetic activity of larch at high altitude on the Ural Mountains LiCor 6400 gas analiser

Shoots and needle of larch Last annual long shoot Brachyblasts on the annual shoot and trunk 2 year old annual long shoot (auxiblast)

Total biomass of needle(1) and stem(2) at different height of larch tree

Variation of 2 year old annual shoot length (1), number of brachyblasts per 1 shoot (2) and number of needle per 1 brachyblast (3) in the crown of larch tree

1 Biomass of needles (1) and stems (2) on the branch from middle part of larch crown 2

2-8 year old larch brachyblasts Number of needles in brachyblast and length of needle

Apex on transverse section of larch brachyblast

Partial volume (%) of mesophyll in needles of conifer trees Transverse section of larch needle Partial volume (%) of intercellular space in mesophyll

Characteristics of chloroplasts in larch needle in July Spruce Square of chloroplast transverse section (except for starch granule), mkm2 4.0±1.0 8.5±1.1 Number of : granum per 1 chloroplast section 22±5 thylakoids per 1 granum 5±2 7±2 thylakoids per q chloroplast section 110 154 thylakoids per 1 mkm2 chloroplast section 28 18

Photosynthesis of larch (1) and spruce (2) on the Northern Ural in July

Daytime dynamics of PAR (1) and photosynthesis (2) of larch at altitude tree line of North Ural Partly cloudy day 1 2 Cloudless hot day

Photosynthesis of larch needle and microclimatic date in upper part of forest in the North Ural (2006) Date Weather Photosynthesis, mkmol CO2 m-2 s-1 PAR, mkmol m-2 s-1 Air temperature , °С Air moisture, % min max 4 July Partly cloudy 1.49 2.56 278 1194 7 14 41 64 8 July Cloudless 1.44 3.09 282 1834 15 29 27 58 11 July 1.27 3.10 201 1681 23 36 25 57 17 July 2.26 4.20 481 1510 21 31 42 73

Variation of photosynthesis of larches Species Region Ph, mkmol СО2 m2 s-1 Authors L.desidua Europe 3 Beneck et al., 1981 Moscow region 25 (mg СО2 g-1 h-1) Малкина, 1995 L. cajanderi Central Yakutia 6-13 Максимов и др., 2005 L. gmelinii 8-10 Vygodskaya et al., 1997 L. sibirica Irkutsk region Суворова и др, 2003 Komi Republic, extreme north taiga 4-10 (mg СО2 g-1 h-1) Бобкова , Тужилкина, 199 Archangelscaja obl.., 27 (mg СО2 g-1 h-1) Коновалов, 2002 North and Subpolar Ural 3-4 Zagirova S. (unpublished)

Conclusion: High photosynthesis of larch on the Ural Mountains is provided for large needle surface of brachyblasts, intercellular space in mesophyll and peculiar properties of chloroplasts in its cells. Efficiency of photosynthesis depends on weather in vegetation season.

Thank you for attention! The investigations were supported by Project of Presidium RAS “Biological diversity of terrestial and water ecosystems of the Polar Ural” in 2009-2010 Thank you for attention!