Research Progress on Iron-Heart Cunninghamia lanceolate

Cunninghamia lanceolate (Lambert.) Hooker is one of the main fast-growing timber forest species in southern China which has a long history of cultivation and spreads across 28 provinces, cities, and regions. Recently, a variant of fir was discovered in the Xiaoxi National Nature Reserve in Hunan Province. The heartwood is hard as iron and its ratio is more than 80%, with the especial character of anti-corruption. It is a natural germplasm resource, called Iron-heart Cunninghamia lanceolate. Study on it is still in the stage of data accumulation. In this paper, we studied it from three points as follows: (1) Plus tree selection and construction of germplasm resources nursery. (2) Study on cone and seed quality. (3) Genetic structure analysis of natural population. The research of Iron-heart Cunninghamia lanceolate lays a theoretical foundation for the protection, development, and utilization of the black-heart wood germplasm resources of Iron-heart Cunninghamia lanceolate in the future.

Finite Sequentiality of Finitely Ambiguous Max-Plus Tree Automata

We show that the finite sequentiality problem is decidable for finitely ambiguous max-plus tree automata. A max-plus tree automaton is a weighted tree automaton over the max-plus semiring. A max-plus tree automaton is called finitely ambiguous if the number of accepting runs on every tree is bounded by a global constant. The finite sequentiality problem asks whether for a given max-plus tree automaton, there exist finitely many deterministic max-plus tree automata whose pointwise maximum is equivalent to the given automaton.

Resistance of Pinus Sibirica clones to insect conobionts in the Yelbashinsky nursery of JSC «Berdsky forestry» in Novosibirsk region

The inter-clonal variability of Siberian cedar in resistance to insect conobionts was studied. The authors revealed that the main pests of cones and seeds are cone moth Dioryctria abietella Schiff and giant cone moth Eupithecia abietaria Goeze in the archives of plus-tree clones of Novosibirsk region (Yelbashinsky Nursery of JSC «Berdsky forestry», Iskitimsky district). The moth’s infestation of buds was 23.4%, and the infestation of buds by the moth was 2.0%. Selection of cedar for resistance to cone moths can be an effective way to increase yield at breeding and seed production facilities of this breed based on the study of inter-clonal variability in the degree of cone moth damage and other traits. Selection for resistance to cone moth disease will not significantly change stem wood produc- tivity due to the absence of a reliable interclonal correlation between the degree of cone damage and tree size. The authors described the result of the findings of the inter-clone correlation, consisting of a significant positive correlation between cone size and «granularity» and stem height and diameter. This result was against the background of the complete absence of any correlation between cone damage by conobionts and tree and cone size. The authors also concluded that selection for stem wood productivity in cedar would be accompanied by an increase in cone size and «granularity» (and vice versa), while selection for resistance to conobionts will not lead to significant changes in other vegetative and generative traits.

A Reevaluation of Superior Tree Performance After 48 Years for a Loblolly Pine Progeny Test in Southern Arkansas

A plus-tree progeny test of full- and half-sib “superior” loblolly pine (Pinus taeda) was installed in 1969 on the Crossett Experimental Forest (CEF) to consider the performance of 28 improved families with unimproved planting stock from the CEF (family W29). Performance was evaluated using data from young (3-year-old; early 1970s), maturing (25-year-old; 1994), and mature (48-year-old; 2017) trees. With the exception of a single improved family, early survival was high (>80%), with most families exceeding 90%. Three years post-planting, fusiform rust infection rates were also low, with most families having less than 1% of seedlings infected. At this early stage, the unimproved CEF family W29 only slightly underperformed the best full- and half-sib superior families. By 1994, W29 had slightly higher than average merchantable volume. This trend continued for W29 when remeasured in 2017, with the average merchantable volume yield for W29 statistically similar to the most productive families. This study found only limited volume performance gains from crossing plus-trees. However, it was important to note that several of the best height growth-performing families in 1972 were not the highest merchantable volume producers at 25 or 48 years, and some of the worst early performers moved into the upper tiers by the later remeasurements. These outcomes suggest that depending solely on early height performance to select families for long-term (>50 year) volume (especially if adjusted for wood density) or biomass yields may not be the best approach for forest managers seeking to increase carbon sequestration.

Growth of Scots pine plus trees clones, selected by resin productivity in Nizhny Novgorod region

The taxational indicators of clones of plus trees of Scots pine, selected by resin productivity, were studied in comparison with similar characteristics of plants, selected by linear parameters of the trunk. They are represented They are presented in the assortment of the forest seed plantation No. 10 in the Semenovsky forestry of the Nizhny Novgorod region, created in 1984 on a plot with the type of forest growing conditions — B2, and the type of forest — maynikovo-lingonberry pine. In the organization of the work, the principle of the only logical difference was observed, as well as the requirements for the typicality, suitability and expediency of the experience. As a test marker for checking the purity of the clonal composition of the plantation, the value of the angle of attachment of the first-order lateral branches to the trunk was used. The height and diameter of the trunk are taken into account in 571 trees with a continuous list. The distribution of the average values of the analyzed indicators in the vegetative offspring of plus trees compared with each other is not uniform. The highest height (16,70 ± 0,43 m) observed in clones of the K-011 plus tree selected by resin productivity is 2,65 m or 1,19 times higher than the lowest value (14,05 ± 0,44 m) inherent in clones of the K-113 plus tree selected by the same criteria, and 2,02 m or 1,14 times higher than the lowest value (14,23 ± 0,31 m) inherent in clones of the K-171 plus tree selected by the same criteria taxational indicators of the trunk. Differences in the taxational indicators of clones in the group of plus trees distinguished by resin productivity, as well as in the group of trunks distinguished by characteristics, correspond to the level of significant ones, which indicates the specificity of their genotypes. The degree of similarity of the plus trees in terms of trunk parameters is not the same, which indicates a different level of individual non-identity of each of the plus trees in relation to the others in their considered population.

Criteria for Assessment of Plus Oak Stands

In the Voronezh region the share of seed plantations is less than half of the area of oak forests. Therefore, the regeneration of high-quality forests of seed origin with improved hereditary characteristics is a major challenge. In the production of seeds of improved breeding categories, plus stands play an important role. They produce improved seeds, if minus trees are removed. Moreover, permanent forest seed plots which were planted by the plus stand offspring, produce seeds of the required breeding category. Current laws and regulations do not provide specific recommendations on selection of plus stands. To address this issue and establish the criteria by which such forest stands should be selected we examined all the best stands containing plus trees in the Voronezh region (those that are candidates for plus stands). The frequency of occurrence of plus trees varies from 2 to 10 trees per 10 ha. We took the average value as the minimum to classify the forest plot as a plus stand. Marking forest stands as plus stands based on selection inventory data is recommended regardless of the time of the forest management fieldwork. Besides this, we performed a detailed inventory of the plus stand in the quadrant 41 of the Krasnoye divisional forestry area in the Vorontsovskoye forestry area on the area of 10.7 ha. The study was carried out on 10 trial plots (1 ha each), where a selection inventory was conducted, as well as an inventory of trees by technical assessment with a detailed description of each oak specimen by inventory characteristics, condition and the presence of flaws. The data obtained by selection inventory with identification of “good trees” (sum of plus and normally best trees) correlate with distribution of trees by technical assessment categories. The identified patterns can be used for selection inventory of oak plantations. We recommend to place stands in a category of plus stand if their forest density ranges from 0.7 to 0.9, more than 35 % of the trees have commercial wood and if this plot has at least one plus tree per two ha. Restoring oak forests with acorns harvested from plus stands will improve the quality of forest plantations.

Growth and Yield of Avicennia Officinalis (Baen) L. And Heritiera Fomes (Sundri) Buch. Ham. Plantations Established From Plus Tree Seeds in the Western Coastal Belt of Bangladesh

not available Asiat. Soc. Bangladesh, Sci. 46(2): 209-214, December 2020

Finite Sequentiality of Unambiguous Max-Plus Tree Automata

We show the decidability of the finite sequentiality problem for unambiguous max-plus tree automata. A max-plus tree automaton is called unambiguous if there is at most one accepting run on every tree. The finite sequentiality problem asks whether for a given max-plus tree automaton, there exist finitely many deterministic max-plus tree automata whose pointwise maximum is equivalent to the given automaton.