scholarly journals Do Woody Tree Thinning and Season Have Effect on Grass Species’ Composition and Biomass in a Semi-Arid Savanna? The Case of a Semi-Arid Savanna, Southern Ethiopia

2021 ◽  
Vol 9 ◽  
Author(s):  
Malicha Loje Hare ◽  
Xin Wen Xu ◽  
Yong Dong Wang ◽  
You Yuan ◽  
Abule Ebro Gedda
Keyword(s):  
Species Composition ◽  
Woody Plants ◽  
Species Abundance ◽  
Control Plot ◽  
Tree Density ◽  
Grass Species ◽  
Southern Ethiopia ◽  
Forage Production ◽  
Multivariate Technique ◽  
Semi Arid

Encroachment of woody plants has negative effects on grass species and seriously challenging livestock production and pastoral livelihood in semi-arid savanna. The effect of thinning and season on grass species composition and biomass was investigated in lowland grazing area for three seasons. The study consisted of 15 plots (each 50 m × 50 m), thinned to differing intensities. The plots were located next to each other on a homogeneous area of 3.8 ha. Five thinning intensities (0, 25, 50, 75, and 100%) were allocated randomly to the plots and replicated three times. The 0% plot was left unthinned referred to as the control plot. The remaining plots were thinned to the equivalents of 25, 50, 75, and 100% of the tree density of that of the control plot. A two-way analysis of variance and Tukey Honest Significant Differences tests were used to compare responses of grass species. Ordination of variables was carried out by multivariate technique using correspondence analysis to explore the similarity relationship of plots, seasons and species. The differences in species composition and biomass in the control and the thinned plots were significant (p < 0.05). Higher grass species composition and biomass were documented in thinned plots than in the control plot. Species abundance in thinned plots ranged from 11 to 12, while that of the 0% plot was six species. Grass biomass (Kg ha-1) varied from 2,688.4 ± 736.8 to 5,035.8 ± 743.9 across thinned plots, whereas in the control plot the yield was 885.8 ± 369.1. The result showed that grass species composition and biomass increased with the increasing intensity of thinning. Grass values appeared to be optimum at the heavy intensity of thinning woody plants. Seasons were also significant with the highest values recorded in the rainy season. Rainfall played an important role by interacting with thinning and influenced total grass values. Overall, thinning that combined improved soil moisture negatively influenced woody cover and enhanced grass species composition and biomass production. Thinning of bushes to the 75% of tree density would sustain the original savanna and maximize forage production for grazers.

scholarly journals Effect of disturbance on plant species abundance and density distribution in tropical forest of Sunsari district, Eastern Nepal

2016 ◽  
Vol 6 (1) ◽  
pp. 1-12
Author(s):  
Tilak Prasad Gautam ◽  
Tej Narayan Mandal
Keyword(s):  
Carbon Sequestration ◽  
Species Composition ◽  
Tropical Forest ◽  
Tropical Forests ◽  
Tree Species ◽  
Forest Disturbance ◽  
Species Abundance ◽  
Forest Degradation ◽  
Tree Density ◽  
Shrub Species

The disappearance of global tropical forests due to deforestation and forest degradation has reduced the biodiversity and carbon sequestration capacity. In these contexts, present study was carried out to understand the species composition and density in the undisturbed and disturbed stands of moist tropical forest located in Sunsari district of eastern Nepal. Study revealed that the forest disturbance has reduced the number of tree species by 33% and tree density by 50%. In contrary, both number and density of herb and shrub species have increased with forest disturbance.

scholarly journals Does Geijera parviflora Lindl. (Rutaceae) facilitate understorey species in semi-arid Australia?

2007 ◽  
Vol 29 (2) ◽  
pp. 207 ◽  
Author(s):  
A. D. Warnock ◽  
M. E. Westbrooke ◽  
S. K. Florentine ◽  
C. P. Hurst
Keyword(s):  
Soil Moisture ◽  
Species Composition ◽  
Seed Bank ◽  
Nutrient Concentration ◽  
Species Abundance ◽  
Soil Nutrient ◽  
Nutrient Concentrations ◽  
Arid Zones ◽  
Understorey Vegetation ◽  
Semi Arid

Species composition under tree canopies often differs from that of surrounding micro-environments. In arid and semi-arid zones, trees can be beneficial to understorey vegetation. This study examined zones of vegetation composition and soil physiochemical parameters associated with Geijera parviflora Lindl. The importance of shade, rainfall redistribution, seed bank and soil moisture were examined. Species abundance, soil moisture, seed bank composition, rainfall redistribution and soil nutrient concentration were measured under five randomly selected mature G. parviflora trees in south-western New South Wales, Australia. To complement the findings from this study, artificial shade plots were constructed in a canopy-free area and species abundance measured seven months after shade construction. The study demonstrated that G. parviflora was associated with zonation of understorey vegetation. Two zones of understorey vegetation were found in relation to G. parviflora: (i) under the tree canopy with high species diversity, and (ii) beyond the canopy, this community being dominated by Dissocarpus paradoxus throughout the year with Crassula colorata appearing after rainfall. The zone beyond the canopy also had lower soil nutrient concentrations. Soil moisture, nutrient concentration and the seed bank density were significantly higher under the canopy. However, the canopy reduced precipitation reaching the soil surface. The effects of the canopy on understorey species composition and soil moisture were enhanced after winter rainfall. Artificial shade increased species abundance and richness under a 90%-shading treatment. The results indicated that G. parviflora generated spatial heterogeneity over the broader plant community increasing species richness, abundance and diversity under the canopy. This emphasises the importance of arid zone trees in conserving understorey plant diversity. Shading, soil nutrient concentration and increased seed bank density and soil moisture appeared to be key influences on the plant communities under the canopy.

scholarly journals 111 Metsulfuron and variable nitrogen application rates on infected tall fescue: effects on stocker performance, forage yield, nutritive value, ergovaline concentration and botanical composition

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 31-31
Author(s):  
Kevin R Meng ◽  
Eric Bailey ◽  
Josh Zeltwanger ◽  
Hannah Allen ◽  
Mikaela Adams ◽  
...  
Keyword(s):  
Species Composition ◽  
Tall Fescue ◽  
Nutritive Value ◽  
Ergot Alkaloids ◽  
Fertilization Rate ◽  
Forage Yield ◽  
Nitrogen Application ◽  
Forage Production ◽  
Seed Head ◽  
Application Rates

Abstract Chemical seed-head suppression of endophyte infected tall fescue (Lolium arundinaceum) improves stocker cattle performance but may decrease forage yield. Spring nitrogen application increases tall fescue growth with a concomitant increase in ergot alkaloids, produced by the symbiotic endophyte Epichloë coenophiala. We hypothesized that greater amounts of nitrogen applied to tall fescue would increase forage yield and offset losses in forage production from chemical suppression of seed-heads with metsulfuron without effect on alkaloid concentration. Ninety-six steers (270 ± 20 kg) were randomly assigned to one of sixteen paddocks (1.8 ha) on April 18 and continuously grazed for 57 d. Paddocks were blocked by previous use (n = 4) and randomly assigned to one of four treatments; no metsulfuron, no nitrogen (NEGCON), metsulfuron with 0 (MET0), 67 (MET67), or 134 (MET134) kg/ha of ammonium nitrate, applied March 11. Steers grazing MET0 paddocks were removed 17 d early due to insufficient forage availability. Steer weight, forage yield, forage nutritive value and ergot alkaloids in forage samples were measured monthly. Seed-head frequency and species composition were determined in June. Metsulfuron application reduced (P < 0.01) tall fescue seed-heads by 80%. Metsulfuron decreased (P = 0.03) ergovaline but ergovaline increased (P < 0.01) at each monthly sampling across treatments. Nitrogen had no impact on ergovaline concentration (P = 0.50). Forage yield tended to be least (P = 0.07) for MET0, intermediate for NEGCON and MET67, and tended to be greatest for MET134 (P = 0.08). Steer ADG was not affected by treatment (P < 0.80). Metsulfuron decreased NDF (P=0.02) regardless of fertilization rate. Forage CP increased with fertilization (P < 0.01) and no differences were detected between NEGCON and MET0 (P = 0.45). Species composition was not impacted (P >0.07) by treatment. Metsulfuron decreased seed-head growth and ergovaline concentration in tall fescue. Additional nitrogen fertilizer ameliorated forage yield lost to metsulfuron application but did not impact steer gain.

The use ofin vitrogas production to evaluate rumen fermentation of leaves of 24 browse species indigenous to semi-arid areas of Zimbabwe

1998 ◽  
Vol 22 ◽  
pp. 238-240
Author(s):  
L. R. Ndlovu ◽  
L. Hove
Keyword(s):  
Woody Plants ◽  
Nutritive Value ◽  
Gas Production ◽  
Arid Areas ◽  
Chemical Methods ◽  
Tropical Regions ◽  
Biological Assays ◽  
Browse Species ◽  
Semi Arid

Browse species are important food resources in semi-arid areas, especially during the dry season when the nutritive value of grass is at its lowest. However, browse plants often contain secondary plant compounds which limit their nutritive value. Proanthocyanidins (PAs) (also called condensed tannins) and related flavonoids are a common constituent of woody plants in tropical regions (Mangan, 1988). PAs cause a bitter and astringent taste which lowers food palatability and they also lower the digestibility of proteins and carbohydrates (Jacksonet al., 1996). PAs also interfere with current chemical methods that are used for estimating nutritive value of foods (Reed, 1995). Biological assays, especially ,in vitrotechniques, have a potential to reflect better the nutritive value of foods that contain PAs. Thein vitrogas production technique has been found to reliably predict the nutritive value of temperate forages (Makkaret al., 1996). There has been limited research on its efficacy with tropical forages. The experiment reported here was conducted to test the hypothesis that gas production of tropical browse species reflects their content of fibre, protein and/or PAs.

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