scholarly journals Plant communities responding to grazing pressure by sheep in an Alpine meadow

2020 ◽  
Vol 4 (2) ◽  
pp. 1174-1181
Author(s):  
Jianping Wu ◽  
Xuyin Gong ◽  
Xixi Yao ◽  
David P Casper
Keyword(s):  
Plant Communities ◽  
Nutritional Quality ◽  
Nutritional Value ◽  
Net Primary Production ◽  
Average Daily Gain ◽  
Livestock Grazing ◽  
Grassland Ecosystem ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
The Impact

Abstract The Chinese grassland ecosystem is an important national asset that not only impacts climate regulation, soil and water conservation, wind protection, and soil carbon and nitrogen fixation but is also an important contributor to maintaining grassland biodiversity while supporting livestock production. Grasslands are a key component contributing to the productivity of grazing animals but also provide basic food production via livestock grazing for herder survival. Grazing is the most basic means of grassland utilization but is considered one of the more important disturbance factors controllable by humans that has a universal and profound impact on the grassland ecosystem due to animal density and over grazing. For Alpine grasslands, it is not clear what grazing intensity (GI) can be achieved to improve plant biodiversity and vegetative nutritional value while improving sheep productivity. This field experiment was conducted for 7 yr comparing the impact of different GI on vegetation community characteristics, nutritional value, and sheep growth performance on the Alpine meadows of the Qinghai–Tibetan Plateau. The GI measured were: Control: 0 sheep/ha; Low: 3.7 sheep/ha; Medium: 5.3 sheep/ha; and Heavy: 7.6 sheep/ha. The grazing experiment started in 2008, but experimental data collection and analyses were collected for the final 4 yr of 2015 through 2018. All grazing intensities >0 sheep/ha reduced (P < 0.05) plant height (27%, 46%, and 48%, respectively, for 3.7, 5.3, and 7.6 sheep/ha), ground coverage (16%, 24%, and 48%), and above ground biomass (2%, 42% and 53%) of the various plant communities while increasing (P < 0.05) the grass community density (individuals/m2) compared to a nongrazed Control. With increasing GI, the community height, coverage, and above-ground biomass decreased (P < 0.05), and the plant community density increased then decreased (P < 0.05) compared to Control. As GI increased, the available community biomass nutritional quality increased (P < 0.05). Comprehensive analysis showed that the community density (quantity) and nutritional quality were the highest when the GI was 5.3 sheep/ha. The higher the GI, the greater the grass’s nutritive value with lower above-ground net primary production (ANPP). When GI was the highest, the average daily gain (ADG) per hectare was the highest in the short term, but the highest GI endangers the ANPP and profitability of the grassland grazing ecosystem in the long term. Targeting a moderate GI (5.3 sheep/ha) can provide 78% of the ADG per hectare of the highest GI, which meets the requirement of maintaining a sustainable grazing grassland.

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

scholarly journals Opposite effects of nutrient enrichment and herbivory by an alien snail on growth of an invasive macrophyte and native macrophytes

2021 ◽  
Author(s):  
Yimin Yan ◽  
Ayub M.O. Oduor ◽  
Feng Li ◽  
Yonghong Xie ◽  
Yanjie Liu
Keyword(s):  
Nutrient Enrichment ◽  
Animal Species ◽  
Biomass Yield ◽  
Freshwater Ecosystems ◽  
Pomacea Canaliculata ◽  
Above Ground Biomass ◽  
Aquatic Habitats ◽  
Ground Biomass ◽  
Invasive Spread ◽  
The Impact

Human-mediated introduction of plant and animal species into biogeographic ranges where they did not occur before has been so pervasive globally that many ecosystems are now co-invaded by multiple alien plant and animal species. Although empirical evidence of invaders modifying recipient ecosystems to the benefit of other aliens is accumulating, these interactions remain underexplored and underrepresented in heuristic models of invasion success. Many freshwater ecosystems are co-invaded by aquatic macrophytes and mollusks and at the same time experience nutrient enrichment from various sources. However, studies are lacking that test how nutrient enrichment and co-invasion by alien herbivores and plant species can interactively affect native plant communities in aquatic habitats. To test such effects, we performed a freshwater mesocosm experiment in which we grew a synthetic native macrophyte community of three species under two levels of nutrient enrichment (enrichment vs. no-enrichment) treatment and fully crossed with two levels of competition from an invasive macrophyte Myriophyllum aquaticum (competition vs. no-competition), and two levels of herbivory by an invasive snail Pomacea canaliculata (herbivory vs. no-herbivory) treatments. Results show that herbivory by the invasive snail enhanced above-ground biomass yield of the invasive macrophyte. Moreover, the invasive herbivore preferentially fed on biomass of the native macrophytes over that of the invasive macrophyte. However, nutrient enrichment reduced above-ground biomass yield of the invasive macrophyte. Our results suggest that eutrophication of aquatic habitats that are already invaded by M. aquaticum may slow down invasive spread of the invasive macrophyte. However, herbivory by the invasive snail P. canaliculata may enhance invasive spread of M. aquaticum in the same habitats. Broadly, our study underscores the significance of considering several factors and their interaction when assessing the impact of invasive species, especially considering that many habitats experience co-invasion by plants and herbivores and simultaneously undergo varous other disturbances including nutrient enrichment.

scholarly journals Impact of tidal height on characteristics of ALOS PALSAR measurements to estimate above ground biomass of mangrove forest in Indonesia

2018 ◽  
Author(s):  
Ketut Wikantika
Keyword(s):  
Mangrove Forest ◽  
Impact Analysis ◽  
Time Series Data ◽  
Tidal Height ◽  
Series Data ◽  
Above Ground Biomass ◽  
Large Area ◽  
Alos Palsar ◽  
Ground Biomass ◽  
The Impact

Mangrove has the most carbon rich forests in the tropics. Mapping and monitoring biomass of mangrove forest is very important to manage ecosystem and field survey of mangrove biomass and productivity is very difficult due to muddy soil condition, heavy weight of the wood, very large area and tidal effect on mangrove area. Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) is available for identification and monitoring mangrove forest. The objective of this research is to investigate the impact of tidal height on characteristics of HH and HV derived from ALOS PALSAR for estimation above ground biomass of mangrove forest. Methodology consists of collecting of tidal height data in the study area, ALOS-PALSAR time series data, region of interest (ROI) on mangrove forest, characterization of HH and HV and impact analysis of tidal height on HH and HV. The result of this research has showed the impact of tidal height on characteristics HH and HV on mangrove forest types derived from ALOS-PALSAR and proposed the model for estimation aboveground biomass of mangrove forest.

Maximum flood depth characterizes above-ground biomass in African seasonally shallowly flooded grasslands

2007 ◽  
Vol 23 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Paul Scholte
Keyword(s):  
Dry Season ◽  
Perennial Grasses ◽  
Individual Species ◽  
Above Ground Biomass ◽  
Nutrient Quality ◽  
Flood Duration ◽  
Ground Biomass ◽  
Flood Depth ◽  
The Individual ◽  
The Impact

Flood depth has been frequently used to explain the distribution of plant species in seasonally flooded grasslands, but its relation with vegetation production has remained ambiguous. The relationship between flooding and above-ground biomass at the end of the flooding season and during the dry season was studied to assess the impact of reflooding on the Logone floodplain, Cameroon. Above-ground biomass of a combination of all species and of the individual perennial grasses Oryza longistaminata and Echinochloa pyramidalis showed a positive linear relationship with maximum flood depth up to 1 m. The gradient of these relationships became steeper and their fit better during the 2 y following the installation of the flooding, showing the response lag to floodplain rehabilitation. Flood duration only explained the above-ground biomass of the combination of all species and not of the individual species. Above-ground biomass data from other floodplains in the three main African geographic regions showed a similar relationship with maximum flood depth less than 1 m. Dry-season regrowth, important because of its high nutrient quality during forage scarcity, was not directly related to maximum flood depth, possibly because of its dependency on the period of burning and soil moisture. Presented data indicate that a rise of water level of 1 cm corresponds to an increase in above-ground biomass of c. 150 kg DM ha−1.

The impact of selective logging and clearcutting on forest structure, tree diversity and above-ground biomass of African tropical forests

2014 ◽  
Vol 30 (1) ◽  
pp. 119-132 ◽  
Author(s):  
Roberto Cazzolla Gatti ◽  
Simona Castaldi ◽  
Jeremy A. Lindsell ◽  
David A. Coomes ◽  
Marco Marchetti ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Forest Structure ◽  
Tree Diversity ◽  
Selective Logging ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Structure Tree ◽  
The Impact

scholarly journals Chemical Composition of the Above-ground Biomass of Amaranthus cruentus and A. hypochondriacus

2006 ◽  
Vol 75 (1) ◽  
pp. 133-138 ◽  
Author(s):  
B. Písaříková ◽  
J. Peterka ◽  
M. Trčková ◽  
J. Moudrý ◽  
Z. Zralý ◽  
...  
Keyword(s):  
Crude Protein ◽  
Nutritional Value ◽  
Experimental Period ◽  
Growth Stages ◽  
Above Ground Biomass ◽  
Crude Fibre ◽  
Amaranthus Cruentus ◽  
Ground Biomass ◽  
Extract Content ◽  
Gross Energy

Forty samples of dry above-ground biomass of two species and four varieties of Amaranthus cruentus (varieties Olpir, Amar 2 RR-R 150, and A 200 D) and A. hypochondriacus (variety No. 1008) were analyzed to determine their nutritional value during the experimental period covering five growth stages since inflorescence emergence till full ripening of grain from day 80 to day 120 of cultivation. The content of crude protein in the investigated amaranth varieties significantly decreased (from 158.2 ± 1.20 - 185.4 ± 2.33 to 103.8 ± 1.20 - 113.1 ± 0.01 g/kg) as well as did the crude ash content (from 169.9 ± 0.14 - 192.2 ± 0.42 to 129.7 ± 0.14 - 138.4 ± 0.21 g/kg). In contrast, the ether extract content significantly increased (from 12.2 ± 0.14 - 15.9 ± 0.28 to 28.0 ± 0.28 - 36.4 ± 0.14 g/kg) as well as crude fibre (from 144.9 ± 2.12 - 170.0 ± 3.68 to 183.6 ± 7.00 - 276.0 ± 1.20 g/kg), and gross-energy (from 16.6 ± 0.03 - 17.2 ± 0.07 to 18.1 ± 0.14 - 18.4 ± 0.01 MJ/kg) between days 80 and 120 of cultivation. The relatively high content of crude protein in the aboveground biomass in the period between days 80 and 90 of cultivation suggests that the plants could be used as a nutrient substitute for conventional forages.

Sign in / Sign up

Export Citation Format

Share Document