|Influence of environments on the formation of Larix cajanderi
Mayr wood anatomy in the amur River Region, Russian Far East
Blokhina N.I.1, Bondarenko O.V.1, Osipov S.V.2
1Institute of Biology and Soil Science FEB RAS, Vladivostok, Russia,
2Pacific Institute of Geography FEB RAS, Vladivostok, Russia, firstname.lastname@example.org
The Cajander larch, Larix cajanderi Mayr, is one of the main forest-forming species in the boreal zone of the continental Russian Far East (RFE). The species is characterized by the broad edaphic range, and it grows well in sites with a variety of soils: permafrost, waterlogged and dry, peaty and stony, rich and poor in mineral nutrients. The purpose of this work is to characterize specific features of the formation of L. cajanderi wood anatomy, the process and rate of mature wood formation under the influence of environments in the Amur River region, RFE. The materials for our study were collected in the montane taiga belt of the Bureya River basin (51°41' N, 134°18' E, 600 m a.s.l., the Amur River basin, Khabarovsk Region, RFE).
Age variability of the L. cajanderi wood anatomy has been studied in the direction from pith to bark at the level of 1.3 m above the ground, i.e. at breast height, on 4 model trees taken from different area points. The L. cajanderi model trees Nos. 1 and 4 were selected on a river terrace in open larch woodland. Height of the terrace is 2 m above river level. Habitat of the community is more rigorous than zonal one because of permafrost and overwetting. The model tree No. 2 was selected in a larch forest on a down part of W slope (azimuth 270°, tilt 5°). Habitat of the forest is closed to a zonal site. The model tree No. 3 was selected on a river terrace in a larch forest. Height of the terrace is 1 m above river level. It consists of alluvial deposits and does not include permafrost. Habitat of the community is one of the best for L. cajanderi growth in the montane taiga belt of a region. This habitat is more comfortable than environment in a zonal site. All model trees are typical for the plant communities.
The model tree No. 1 is characterized with 8.3 m height and 11 cm diameter with 237 growth rings of 0.06-1.07 (in average 0.22) mm wide at breast height. The model tree No. 2 is characterized with 14.6 m height and 17.5 cm diameter with 119 growth rings of 0.10-0.80 (in average 0.30) mm wide at breast height. The model tree No. 3 is characterized with 23.6 m height and 25 cm diameter with 138 growth rings of 0.05-3.07 (in average 0.96) mm wide at breast height. The model tree No. 4 is characterized with 6.5 m height and 8.5 cm diameter with 260 growth rings of 0.05-0.45 (in average 0.14) mm wide at breast height.
Comparative analysis of the age variability of wood anatomy has shown that the earliest formation of mature wood (in the growth rings nos. 31-40 inclusively) is characteristic of the model tree No. 3 selected from habitat more comfortable than environment in a zonal site. In the model tree No. 2 taken from habitat closed to zonal site, mature wood is forming in the growth rings nos. 51-60 inclusively, and in the model trees from habitat more rigorous than zonal one, mature wood is forming in the growth rings nos. 91-100 inclusively in the model tree No. 1, whereas in the No. 4 anatomical features characteristic the mature stem wood are not forming, For instance, the No. 4 differs from the other model trees by the lacking of triseriate fusiform rays containing resin canals, and elliptic biseriate bordered pits in the radial walls of tracheids. Besides, this model tree is characterized by shorter uniseriate rays, and smaller pits in the radial walls of earlywood tracheids as well as a very occasional presence of 7-8 pits per cross-fields. In addition to the above, the model tree No. 4 has narrowest growth rings. The model trees Nos. 1 and 4 come from the same habitats with permafrost and overwetting, however, wood anatomical structure of the tree No 4 testifies more overwetting site than that of the No 1.
Correlation between the formation of wood anatomical structure in L. cajanderi and habitat environments was considered for the first time.
This work was supported by the Russian Foundation for Basic Research (project no. 08-04-00419), and the Presidium of the Russian Academy of Sciences and the Presidium of the Far East Branch of the Russian Academy of Sciences (project no. 09-I-P15-02).