Undergrowth

About: Undergrowth is a research topic. Over the lifetime, 795 publications have been published within this topic receiving 11911 citations. The topic is also known as: understorey & underbrush.

Suppressed Undergrowth of Siberian Spruce (Picea obovata Ledeb.) in Early Ontogeny: One-Way Ticket or Survival Strategy?

Abstract: The study examined the growth characteristics of the Siberian spruce (Picea obovata Ledeb.) under the canopy of coniferous forests in early ontogeny. We revealed that spruce undergrowth in adverse conditions is suppressed, is slow to grow and has xylorhizomes. The result is a significant difference in height, age and stage of ontogeny that affects the forest’s growth dynamics. The formation of xylorhizomes changes the relative dimensions of the above-ground part and the plant’s absolute height from 42 to 75%, depending on age. We identified two periods of growth intensity (slow and stable) and the critical age for spruce undergrowth to move from one stage of ontogeny to the next. If it does not make the transition, it will die. There are two strategies for developing spruce undergrowth: a “direct” path during rapid growth and a “waiting” path when the plants are suppressed. Such growth pathways in the pre-generative stage of the Siberian spruce’s ontogeny allow the undergrowth, even in a suppressed state, to survive in an adverse environment under the forest canopy.

Species Diversity in Undergrowth of Artificial Forests on Lower Hilly Land

Abstract: Artificial pure forests of Pinus rigida var. serotina, P. elliottii,Eucalyptus robusta,Schima superba, Liquidambar formosana,and mixed forests of L. formosana / P. massoniana or P. elliottii,which were planted in 1991 in seriously disturbed lower hilly land in Taihe county, Jiangxi Province, were investigated after 10 years. Changes of species diversity in the restored vegetation were measured. Before afforestation there were only 7 species such as Setaria viridis,Arundinella hirta,Rosa laevigata and Smilax china. In 1993 and 2001, the number of species increased to 21 and 58, respectively. In condition of the same density of plantation, the species diversity in the vegetation of the plantations was high in pure conifer forest, followed by conifer broadleaved mixed forest and broadleaved pure forest. The effects of afforestation species, stand structure (pure or mixed) and especially stand density on species diversity were obivious. However, conifer forest was poor in water holding, the soil under which had lower content of organic matters. Conifer broadleaved mixed forest is best for maintenance and restoration of species diversity and for improvement of soil and ecological environment.

Changes in the spruce forests of the Polish Tatra Mts. during the last 80 years

Abstract: On the basis of the historical (dating from the 1920s) and contemporary phytosociological releves, taken in the spruce forests of the Polish Tatra Mts., the changes were determined that took place in these forests. This area had been for centuries under the influence of human economic activities, mainly pasturing and wood extraction, and then protected in the Tatra National Park. These changes differ according to the altitudinal vegetation belts. In the coniferous forests of the upper montane belt, the changes due to wind breaks or tree stand ageing did not lead to transition to other forest associations. A tendency can yet be noticed of losing a part of the species combinations characteris- tic for the associations or higher syntaxonomic units, which might be linked with the stopping of grazing in the forests and de- velopment of the undergrowth of tall herb character. The association of the fir-and-spruce forests in the lower montane belt displayed much bigger changes. There was an in- crease of the role of species of the deciduous forests, while the role of the coniferous forest species was limited in the studied patches, which clearly indicates the evolution of the forests towards the beech woods, typical for the lower montane belt. This means a progressing limitation of the spruce forests in the limestone Tatras to the advantage of return of the beech woodsdominated there in older time.

Development of undergrowth phenological spruce forms in different species composition of forest stands

Abstract: The aim of research was to determine peculiarities of relations between mature layer of the stand with distribution of spruce (Picea abies. Kr.) regeneration according phenology forms and growth specifics. The study examined the success of the resumption of spruce in the Leningrad region under the canopy of the parent stand. In stands with different share of spruce and in various forest-typological conditions, the features of the relationship between the maternal canopy of the stand, the distribution of the natural resumption of spruce by phenological forms and its course of growth were investigated. The account of the undergrowth was carried out by two methods: continuous reading and selective-statistical method. Regardless of the state of viability of spruce undergrowth, the increase in success of regeneration goes from a late vegetation season growth start form to an early one. Under the canopy of the maternal tree stand, young spruce of the early form has the best growth and development indices. In general, under the canopy of spruce stands, the annual height increment in spruce undergrowth, regardless of the phenological structure, the size categories and the state of viability, is greater than under the canopy of pine, pine-spruce and birch-spruce stands. The best characteristics of spruce undergrowth, regardless of phenological forms in vaccinio-myrtillo-pinetum type of forest. When analyzing the characteristics of spruce undergrowth under the canopy of the stand, taking into account the phenological and altitudinal structure, and the state of viability, it was revealed that at the average age prevailing in the spruce undergrowth of the transitional form, the best parameters of growth have small and medium forms and growth in the early form. Analyzing the characteristics of spruce undergrowth under the canopy of the stand, taking into account the phenological and height structure, as well as vitality status, it was revealed that at average age, dominating for the spruce undergrowth of transitional form, the best parameters of small and medium groups of undergrowth has early vegetation season growth start form. The best parameters of the growth have a large group of undergrowth of late vegetation season growth start form.