scholarly journals Photosynthetic parameters of a sedge-grass marsh as a big-leaf: effect of plant species composition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Markéta Mejdová ◽  
Jiří Dušek ◽  
Lenka Foltýnová ◽  
Lenka Macálková ◽  
Hana Čížková
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Photosynthetic Parameters ◽  
Acorus Calamus ◽  
Dominant Plant Species ◽  
Local Plant ◽  
Rate Of Photosynthesis ◽  
Carex Acuta ◽  
Leaf P

AbstractThe study estimates the parameters of the photosynthesis–irradiance relationship (PN/I) of a sedge-grass marsh (Czech Republic, Europe), represented as an active “green” surface—a hypothetical “big-leaf”. Photosynthetic parameters of the “big-leaf” are based on in situ measurements of the leaf PN/I curves of the dominant plant species. The non-rectangular hyperbola was selected as the best model for fitting the PN/I relationships. The plant species had different parameters of this relationship. The highest light-saturated rate of photosynthesis (Asat) was recorded for Glyceria maxima and Acorus calamus followed by Carex acuta and Phalaris arundinacea. The lowest Asat was recorded for Calamagrostis canescens. The parameters of the PN/I relationship were calculated also for different growth periods. The highest Asat was calculated for the spring period followed by the summer and autumn periods. The effect of the species composition of the local plant community on the photosynthetic parameters of the “big-leaf” was addressed by introducing both real (recorded) and hypothetical species compositions corresponding to “wet” and “dry” hydrological conditions. We can conclude that the species composition (or diversity) is essential for reaching a high Asat of the “big-leaf ”representing the sedge-grass marsh in different growth periods.

PERENNIAL MONITORING OF A PASTURE DEPRESSION DEVELOPMENT UNDER DIFFERENT LOADS OF THE TERSKO-KUMSKAYA LOWLAND

1970 ◽  
pp. 15-18
Author(s):  
М. А. Babaeva ◽  
S. V. Osipova
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Plant Communities ◽  
Vegetation Cover ◽  
Climatic Factors ◽  
Atmospheric Precipitation ◽  
Anthropogenic Pressure ◽  
Dominant Plant Species ◽  
Composition And Structure

Changes in phytocenoses in the long-term regime under the influence of anthropogenic pressure, natural and climatic factors are considered. Under the conditions of growing external influence the ordinary components of the community are transformed into its dominant synanthropic forms. Geobotanical studies have shown the heterogeneity of the vegetation cover of pastures in terms of phytocenotic composition, which is in a state of severe disruption. The long-term monitoring studies of pastures show that a complex of environmental factors has a significant impact on the change in species composition and structure under various loads. Change in the vegetation cover under the influence of weak grazing is disappearance of large-sod grasses of the Stipa series with a predominance of small-sod grasses such as Festuca sulcata. Intensive grazing causes disappearance of Festuca sulcata, as well as appearance of small Artemisia shrubs and more competitive plant species that cause changes in plant communities. Such changes make it possible to determine the dominant plant species, during the development of which the next transition of penetration into plant communities of other species begins. The phytocenoses of the compared species of this region differ in the structure and productivity of the dominant forage plants which give the highest phytomass depending on the humidity of the period and the type of load. The purpose of this work is to show the long-term influence of climatic factors in the absence of a minimum of atmospheric precipitation, as well as anthropogenic influences on the transformation of phytocenoses, changes in the structure of the vegetation cover of the semi-desert at different stages of loading. The article presents research data for several years on the species composition and productivity of pastures, depending on the load by the seasons of the year. The results of monitoring studies have established the number of dominant species and their productivity of phytocenoses at different stages of development of vegetation degradation.

scholarly journals Designing cluster plots for sampling local plant species composition for biodiversity management

2020 ◽  
Vol 29 (1) ◽  
pp. e002 ◽  
Author(s):  
Christie Quon ◽  
Tzeng-Yih Lam ◽  
Ho-Tung Lin
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Forest Inventory ◽  
Similarity Index ◽  
National Forest Inventory ◽  
National Forest ◽  
Similarity Indices ◽  
Local Plant ◽  
Plot Area ◽  
Design Factors

Aim of study: Cluster plot designs are widely used in national forest inventory systems to assess current forest resources. By spreading subplots apart, a cluster plot could potentially capture a large variety of local plant species. This aspect has rarely been examined in the past. This study is conducted to understand how design factors of a cluster plot affect estimates of local plant species composition.Area of study: Two large census forest plots in Taiwan and Peninsular Malaysia over 25 ha with different species richness were used.Material and methods: Design factors of a cluster plot were plot configuration (PCONFIG), plot area (PAREA), cluster layout (CLAYOUT), and extent of ground area covered by a cluster (CEXTENT). Jaccard and Sørensen similarity indices were used to compare species compositional similarity between two cluster plot designs. A simulation study was carried out.Main results: Results were consistent among the study sites and similarity indices. PAREA, CLAYOUT, and CEXTENT notably influenced how species composition was sampled. Larger PAREA increased similarity in species composition between two cluster plot designs. Square and rectangle CLAYOUT had the most dissimilar species composition between them. Larger CEXTENT decreased similarity in species composition.Research highlights: We recommend that for CEXTENT ≤ 1000 m2 and PAREA ≤ 500 m2, a cluster plot of rectangle CLAYOUT is preferred for information gain. The study could potentially benefit forest managers designing cluster plots for plant diversity assessment.Keywords: Biodiversity assessment; composition similarity; national forest inventory; species diversity; sampling design; sampling efficiency.Abbreviation used: extent of ground area covered by a cluster (CEXTENT); cluster layout (CLAYOUT); Jaccard similarity index (JAC); plot area (PAREA); plot configuration (PCONFIG); Sørensen similarity index (SOR).

In Situ Burning and Ecological Recovery in an Oil-Impacted Phragmites australis Tidal Freshwater Marsh at Delta National Wildlife Refuge, Louisiana

2017 ◽  
Vol 2017 (1) ◽  
pp. 2348-2368
Author(s):  
Scott Zengel ◽  
Jennifer Weaver ◽  
Zachary Nixon ◽  
Susan L. Wilder ◽  
Jeff Dauzat ◽  
...  
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Phragmites Australis ◽  
Tidal Freshwater ◽  
Tidal Freshwater Marsh ◽  
Plant Species Composition ◽  
National Wildlife Refuge ◽  
Marsh Vegetation ◽  
Ecological Recovery

ABSTRACT In situ burning of oiled marshes is a response method that can be more effective and less damaging to the marsh environment than more intrusive manual and mechanical methods, given appropriate conditions for burning. In situ burning has been examined for a variety of oiled marsh types and vegetation species; however, little to no published data are available for in situ burning of oiled Phragmites australis marshes (common reed, Roseau cane). In late May 2014, a pipeline spill occurred in Delta National Wildlife Refuge, Louisiana, releasing an estimated 4,200 gallons of South Louisiana crude oil into a semi-permanently flooded Phragmites tidal freshwater marsh located on the Mississippi River Delta. Due to the remote location, degree of oiling, and difficulty of oil removal within the dense vegetation, an in situ burn was conducted in early June 2014 while the marsh was flooded. In order to examine the effectiveness and environmental effects of in situ burning for this marsh type, and ecological recovery over time, we monitored oiling conditions and ecological metrics for more than two years, comparing sites from three oiling/treatment classes: (a) reference (not oiled or burned), (b) oiled-and-not-burned, and (c) oiled-and-burned. The burn was effective in rapidly removing much of the gross oiling from the marsh, and also reduced residual oiling on the marsh vegetation. Oil concentrations in marsh soils were initially elevated in the oiled-and-burned sites, but were similar to reference conditions and below background levels after three months. Initial oiling and burning drastically affected the marsh vegetation and a common marsh invertebrate; however, overall ecological recovery was relatively rapid and habitat quality in terms of native plant species composition and wildlife value was enhanced by burning at a local scale, at least for several years. Based on these findings, in situ burning appears to be a viable response option to consider during future spills in marshes with similar plant species composition, environmental setting, and oiling conditions.

scholarly journals Family graveyards form underappreciated local plant diversity hotspots in China's agricultural landscapes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng Gong ◽  
Liangtao Li ◽  
Jan C. Axmarcher ◽  
Zhenrong Yu ◽  
Yunhui Liu
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Natural Habitat ◽  
Plant Species Richness ◽  
Agricultural Landscapes ◽  
Natural Habitats ◽  
Landscape Features ◽  
Habitat Islands ◽  
Local Plant ◽  
Ecological Functioning

AbstractIn the intensively farmed, homogenous agricultural landscape of the North China Plain, family graveyards form distinct cultural landscape features. In addition to their cultural value, these graveyards represent semi-natural habitat islands whose potential roles in biodiversity conservation and ecological functioning has remained poorly understood. In this study, we investigated plant species richness on 199 family graveyards of different ages and sizes. In accordance with biogeography theory, both overall and insect-pollinated plant species richness increased with area and age of graveyards. Even small graveyards show a strong potential for conserving local plant richness, and a mosaic of both large and small family graveyards could play an important role in the conservation of farmland biodiversity and related ecosystem functions. The launch of agri-environmental measures that conserve and create semi-natural habitats, in turn benefitting agricultural biodiversity and ecological functioning, has proven difficult in China due to the shortage of dispensable arable land. Given the great value of family graveyards as semi-natural habitats reflected in our study, we propose to focus preliminary efforts on conserving these landscape features as existing, widespread and culturally important semi-natural habitat islands. This would represent an effective, complementary policy to a subsequent re-establishment of other semi-natural habitats for the conservation of biodiversity and ecological functioning in agricultural landscapes.

Drivers of plant species composition of ecotonal vegetation in two fishpond management types

2021 ◽  
Author(s):  
Kateřina Francová ◽  
Kateřina Šumberová ◽  
Andrea Kučerová ◽  
Michal Šorf ◽  
Stanislav Grill ◽  
...  
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Plant Species Composition ◽  
Fishpond Management

In situ studies on alginic acid synthesis and other aspects of the metabolism of Laminaria digitata

1972 ◽  
Vol 50 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Johan A. Hellebust ◽  
Arne Haug
Keyword(s):  
Amino Acids ◽  
Time Course ◽  
Alginic Acid ◽  
Acid Synthesis ◽  
Short Term ◽  
Fresh Weight Basis ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Rate Of Photosynthesis

Amino acids, particularly alanine and aspartate, become more strongly labeled than mannitol in short-term 14C-photoassimilation experiments. The amino acids are the most likely sources of carbon for alginic acid synthesis and respiration in the dark, in contrast to mannitol, which appears to be relatively unavailable. Temperature is very important in determining the rate of loss of recent photoassimilate in L. digitata. The rate of photosynthesis, on a fresh weight basis, is much higher for blades than for stipes.The time course for incorporation of photoassimilated carbon into alginate differs for the stipe and blade both in light and dark periods. Very little 14C enters alginate in blades in the dark, while alginate in stipes acquires considerable amounts of activity during dark periods. Alginate in both blade and stipe acquires 14C predominantly in mannuronic acid residues of their alginate during short-term photoassimilation periods, while guluronic acid residues become relatively more rapidly labeled during dark periods.

scholarly journals Effects of grazing on plant species diversity and above ground biomass in a Trans- Himalayan Rangeland

1970 ◽  
Vol 17 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Anita Pokharel ◽  
Madhu Chhetri ◽  
Chiranjibi P Upadhyaya
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Plant Species ◽  
Diversity Index ◽  
Livestock Grazing ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Grazing Effect ◽  
Significant Difference ◽  
Palatable Species

Limited information is available on the species composition, above ground biomass and its relations to grazing in a trans-Himalayan rangeland. Its assessment is essential for long term conservation and management. In the present study, we compared species composition, phenology, diversity index and biomass between controlled (without grazing) and open (free grazing) plots to assess the effects of grazing in the selected experimental sites of Upper Mustang during July and November 2005. Species encountered were classified as high, medium, low and non palatable and in three life form categories-grasses, shrubs and forbs. The experimental sites are dominated by forbs (80%) followed by grasses (15%) and shrubs (5%). Disturbance caused by grazing affects the phenological characteristics of the plant community. Result also reveals that species diversity, maximum possible diversity, evenness and species richness was higher in the grazed plots during July and November. A comparison of the aboveground biomass in July showed that mean percentage biomass of high, medium and low palatable species is higher in ungrazed plots. In November, the percentage biomass of only medium palatable species was higher in ungrazed plots and rest of the category is higher in grazed plots. Significant difference in July, a peak growing seasons for most of the plant species in the region reveals that the pasture has impact of livestock grazing. Keywords: Biomass, diversity, grazing effect, rangeland, species Banko Janakari: A journal of forestry information for Nepal Vol.17(1) 2007 pp.25-31

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