Changes in plant species composition along an elevation gradient in an old-growth bottomland hardwood-Pinus taeda forest in southern Arkansas1

Old-growth longleaf pine savannas are characterized by diverse ground-layer plant communities comprised of graminoids, forbs, and woody plants. These communities co-exist with variable-aged patches containing similar-aged trees of longleaf pine (Pinus palustris Mill.). We tested the conceptual model that physical conditions related to the cycle of longleaf pine regeneration (stand structure, soil attributes, fire effects, and light) influence plant species’ composition and spatial heterogeneity of ground-layer vegetation. We used a chrono-sequence approach in which local patches represented six stages of the regeneration cycle, from open areas without trees (gaps) to trees several centuries old, based on a 40-year population study and increment cores of trees. We measured soil characteristics, patch stand structure, fuel loads and consumption during fires, plant productivity, and ground-layer plant species composition. Patch characteristics (e.g., tree density, basal diameter, soil carbon, and fire heat release) indicated a cyclical pattern that corresponded to the establishment, growth, and mortality of trees over a period of approximately three centuries. We found that plants in the families Fabaceae and Asteraceae and certain genera were significantly associated with a particular patch stage or ranges of patch stages, presumably responding to changes in physical conditions of patches over time. However, whole-community-level analyses did not indicate associations between the patch stage and distinct plant communities. Our study indicates that changes in composition and the structure of pine patches contribute to patterns in spatial and temporal heterogeneity in physical characteristics, fire regimes, and species composition of the ground-layer vegetation in old-growth pine savanna.

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Short communication: The dissimilarity in plant species composition of savanna ecosystem along the elevation gradient on Flores Island, East Nusa Tenggara, Indonesia

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d210209 ◽

2020 ◽

Vol 21 (2) ◽

Author(s):

Sutomo Sutomo ◽

I Dewa Putu Darma ◽

Rajif Iryadi

Keyword(s):

Species Composition ◽

Plant Species ◽

Plant Community ◽

Short Communication ◽

Elevation Gradient ◽

Floristic Composition ◽

Centella Asiatica ◽

Imperata Cylindrica ◽

Plant Species Composition ◽

Melastoma Malabathricum

Abstract. Sutomo, Darma IDP, Iryadi R. 2020. Short communication: The dissimilarity in plant species composition of savanna ecosystem along the elevation gradient on Flores Island, East Nusa Tenggara, Indonesia. Biodiversitas 21: 492-496. Savannas in Indonesia are located from west to the east across the archipelago. The objective of this research was to investigate the dissimilarity of floristic composition among savannas at different elevations in Flores. Sixteen sampling plots, each measuring 20 x 20 m were spread over the lowland, midland, and upland savannas. We analyzed the differences in plant community composition among the savannas using NMDS ordination and SIMPER analyses available in PRIMER V.6. As many as 41 species of plants were found in all of the sampling plots. The lowland savanna plant community consisted of Themeda arguens, Zoesya sp., Chromolaena odorata, Crotalaria sp., Adenanthera pavonina, Ocimum sp., Lantana camara in the groundcover layer, and Ziziphus jujube, and Borassus flabellifer at the tree layer. The midland savanna had almost similar composition, except the occurrence of Imperata cylindrica and Leucaena leucocephala, and the upland savanna plant species were Cyperus sp., Polygala paniculata, I. cylindrica, Melastoma malabathricum, C. odorata, Centella asiatica, Vaccinium sp., and Cymbopogon sp. The savannas in Flores were invaded by invasive exotic species, namely L. camara and C. Odorata which may pose serious threat to the existence of savannas.

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Comparison of structural and compositional characteristics in old-growth and mature, managed hardwood forests of Minnesota, U.S.A.

Canadian Journal of Forest Research ◽

10.1139/x99-076 ◽

1999 ◽

Vol 29 (10) ◽

pp. 1479-1489 ◽

Cited By ~ 53

Author(s):

C M Hale ◽

J Pastor ◽

K A Rusterholz

Keyword(s):

Species Composition ◽

Plant Species ◽

Coarse Woody Debris ◽

Woody Debris ◽

Structural Features ◽

Hardwood Forests ◽

Plant Species Composition ◽

Managed Forests ◽

Old Growth ◽

Old Growth Forests

Extended rotation of managed temperate hardwood forests is sometimes presumed to provide the important compositional and structural features of old-growth hardwood forests. However, the features of temperate hardwood old-growth and managed stands of extended rotation age have not been fully quantified and compared. This study compared quantitative parameters (density and volume of logs and snags, coarse woody debris volume (volume of logs + volume of snags), the proportion of hollow logs, basal area and tree, sapling, large seedling and small seedling densities), distributional patterns (diameter class and rot class of live trees, decay class of logs), and vascular plant species composition and diversity in old-growth and mature, managed sugar maple (Acer saccharum L.) - basswood (Tilia americana L.) and northern red oak (Quercus rubra L.) stands. Old-growth forests had higher coarse woody debris volumes and higher proportions of hollow logs, of live trees in large diameter classes, of logs in decay classes 1 and 2, and of live trees in rot classes 3-5 than the mature, managed forests. Old-growth and mature, managed forests did not differ significantly in plant species composition. These results indicate that, while older extended-rotation, managed stands can be very similar compositionally to old-growth forests, they differ quantitatively in structural features.

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