scholarly journals Responses of Vegetation and Ground Cover to Spraying a High Elevation, Big Sagebrush Watershed with 2,4-D

1986 ◽  
Vol 39 (2) ◽  
pp. 141 ◽  
Author(s):  
David L. Sturges
Keyword(s):  
Ground Cover ◽  
High Elevation ◽  
Big Sagebrush

scholarly journals Influence of climate and environment on post-fire recovery of mountain big sagebrush

2014 ◽  
Vol 23 (1) ◽  
pp. 131 ◽  
Author(s):  
Zachary J. Nelson ◽  
Peter J. Weisberg ◽  
Stanley G. Kitchen
Keyword(s):  
Great Basin ◽  
Recovery Rate ◽  
Fire Regime ◽  
Seedling Survival ◽  
High Elevation ◽  
Deep Soil ◽  
Big Sagebrush ◽  
Survival Percentage ◽  
Water Recharge ◽  
Recovery Times

In arid and semi-arid landscapes around the world, wildfire plays a key role in maintaining species diversity. Dominant plant associations may depend upon particular fire regime characteristics for their persistence. Mountain shrub communities in high-elevation landscapes of the Intermountain West, USA, are strongly influenced by the post-fire recovery dynamics of the obligate-seeding shrub, mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana [Rydb.] Beetle). This species is a short-distance disperser with a short-lived seedbank, leading to highly variable post-fire recovery times (15–100 years). We investigated the relative importance of site productivity and seasonal climate in explaining the variance in recovery time for 36 fires, comprising a fire chrono-sequence (from 1971 to 2007) for the Great Basin and Colorado Plateau. A. t. vaseyana recovery was positively related to precipitation in the cool season immediately following fire, likely because deep soil-water recharge that persists throughout the growing season enhances first-year seedling survival. Percentage sand fraction positively correlated with recovery rate yet negatively correlated with live cover in unburnt stands. Our data support the hypothesis that post-fire recovery rate of A. t. vaseyana depends on the climatically controlled ephemerality of the regeneration niche, as is likely true for many arid-land shrub species.

scholarly journals Effects of nitrogen and micronutrients on the growth of safflower under limited water conditions in a high-elevation region

Biologija ◽  
2018 ◽  
Vol 64 (3) ◽  
Author(s):  
Mostafa Fattahi ◽  
Mohsen Janmohammadi ◽  
Shahriar Dashti ◽  
Mojtaba Nouraein ◽  
Naser Sabaghnia
Keyword(s):  
Seed Yield ◽  
Leading Edge ◽  
Ground Cover ◽  
Dry Weight ◽  
High Elevation ◽  
Nitrogen Fertilizers ◽  
Rainfed Condition ◽  
Combined Application ◽  
Biological Yield ◽  
Different Levels

Beneficial nanoparticles are at the leading edge of the rapidly developing field of nanotechnology. Nanotechnology applied to nanofertilizers could play a fundamental role in improving the availability of plant nutrients under unfavourable environmental conditions. To evaluate the effects of different levels of nitrogen fertilizer (0, 75, and 150 kg ha–1) and nanostructured micronutrients (Zn, Fe, Cu) on the seed yield of spring safflower, a study was carried out in the highland region of Baneh, Iran. Specific objectives were to assess the effects of combined application of nano-chelated micronutrients and nitrogen on safflower under rainfed conditions. Assessments of morphological traits revealed that application of nitrogen at the rate of 75 kg ha–1 significantly increased the plant height, canopy spread, stem diameter, and plant dry weight. Also, ground cover, canopy spread, capitulum diameter, and the number of the secondary branches were considerably affected by nano-chelated micronutrients, so the highest values were observed in the plants grown with the application of zinc and copper. Results showed that the effects of interaction of nitrogen and micronutrients were significant for the biological yield, seed number, 1000-seed weight, the percentage of unfilled seeds, and seed yield. A comparison of combined treatments showed that the best performance was recorded for plants grown with the application of N0-Zn, N75-Zn, and N150-Cu. The results of the present experiment agreed with the conclusion that utilization of nitrogen may affect the efficiency of micronutrients. Altogether, the results suggested that the application of intermediate levels of nitrogen fertilizers along with nano-chelated Zn can improve safflower production under rainfed condition.

scholarly journals Quantifying Western U.S. Rangelands as Fractional Components with Multi-Resolution Remote Sensing and In Situ Data

2020 ◽  
Vol 12 (3) ◽  
pp. 412 ◽  
Author(s):  
Matthew Rigge ◽  
Collin Homer ◽  
Lauren Cleeves ◽  
Debra K. Meyer ◽  
Brett Bunde ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Environmental Protection Agency ◽  
Mean Squared Error ◽  
Regression Tree ◽  
Remote Sensing Data ◽  
Ground Cover ◽  
Component Composition ◽  
Landsat 8 ◽  
Bare Ground ◽  
Big Sagebrush

Quantifying western U.S. rangelands as a series of fractional components with remote sensing provides a new way to understand these changing ecosystems. Nine rangeland ecosystem components, including percent shrub, sagebrush (Artemisia), big sagebrush, herbaceous, annual herbaceous, litter, and bare ground cover, along with sagebrush and shrub heights, were quantified at 30 m resolution. Extensive ground measurements, two scales of remote sensing data from commercial high-resolution satellites and Landsat 8, and regression tree models were used to create component predictions. In the mapped area (2,993,655 km²), bare ground averaged 45.5%, shrub 15.2%, sagebrush 4.3%, big sagebrush 2.9%, herbaceous 23.0%, annual herbaceous 4.2%, and litter 15.8%. Component accuracies using independent validation across all components averaged R2 values of 0.46 and an root mean squared error (RMSE) of 10.37, and cross-validation averaged R2 values of 0.72 and an RMSE of 5.09. Component composition strongly varies by Environmental Protection Agency (EPA) level III ecoregions (n = 32): 17 are bare ground dominant, 11 herbaceous dominant, and four shrub dominant. Sagebrush physically covers 90,950 km², or 4.3%, of our study area, but is present in 883,449 km², or 41.5%, of the mapped portion of our study area.

Multitemporal distribution analysis of Dodonaea viscosa (L.) Jacq. by remote sensing in Durango, Mexico

2020 ◽  
Vol 13 (8) ◽  
Author(s):  
Marco, A. Márquez-Linares ◽  
Jonathan G. Escobar--Flores ◽  
Sarahi Sandoval- Espinosa ◽  
Gustavo Pérez-Verdín
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Design Methodology ◽  
Supervised Classification ◽  
Satellite Images ◽  
Ground Cover ◽  
Distribution Analysis ◽  
Dodonaea Viscosa ◽  
Artificial Neural ◽  
Landsat Satellite

Objective: to determine the distribution of D. viscosa in the vicinity of the Guadalupe Victoria Dam in Durango, Mexico, for the years 1990, 2010 and 2017.Design/Methodology/Approach: Landsat satellite images were processed in order to carry out supervised classifications using an artificial neural network. Images from the years 1990, 2010 and 2017 were used to estimate ground cover of D. viscosa, pastures, crops, shrubs, and oak forest. This data was used to calculate the expansion of D. viscosa in the study area.Results/Study Limitations/Implications: the supervised classification with the artificial neural network was optimal after 400 iterations, obtaining the best overall precision of 84.5 % for 2017. This contrasted with the year 1990, when overall accuracy was low at 45 % due to less training sites (fewer than 100) recorded for each of the land cover classes.Findings/Conclusions: in 1990, D. viscosa was found on only five hectares, while by 2017 it had increased to 147 hectares. If the disturbance caused by overgrazing continues, and based on the distribution of D. viscosa, it is likely that in a few years it will have the ability to invade half the study area, occupying agricultural, forested, and shrub areas

Current distribution of Nilgiri grass yellow Eurema nilgiriensis Yata (Lepidoptera: Pieridae), with an updated taxonomic key to Eurema of Western Ghats, India

ENTOMON ◽  
2019 ◽  
Vol 44 (1) ◽  
pp. 23-32 ◽  
Author(s):  
P. C. Sujitha ◽  
G. Prasad ◽  
R. Nitin ◽  
Dipendra Nath Basu ◽  
Krushnamegh Kunte ◽  
...  
Keyword(s):  
Current Distribution ◽  
Western Ghats ◽  
Original Description ◽  
High Elevation ◽  
Type Locality ◽  
Ecological Data ◽  
Field Identification ◽  
Wing Patterns ◽  
Southern Western Ghats ◽  
The Nilgiris

Eurema nilgiriensis Yata, 1990, the Nilgiri grass yellow, was described from Nilgiris in southern India. There are not many published records of this species since its original description, and it was presumed to be a high-elevation endemic species restricted to its type locality. Based on the external morphology (wing patterns) as well as the male genitalia, the first confirmed records of the species from Agasthyamalais and Kodagu in the southern Western Ghats, is provided here. This report is a significant range extension for the species outside the Nilgiris, its type locality. Ecological data pertaining to this species as well as the field identification key to all known Eurema of Western Ghats are also presented.

Banking Wyoming big sagebrush seeds

2013 ◽  
Vol 14 (1) ◽  
pp. 60-70 ◽  
Author(s):  
R. P. Karrfalt ◽  
N. Shaw
Keyword(s):  
Big Sagebrush ◽  
Wyoming Big Sagebrush

Effect of fungicide on Wyoming big sagebrush seed germination

2011 ◽  
Vol 12 (3) ◽  
pp. 263-267 ◽  
Author(s):  
R. D. Cox ◽  
L. H. Kosberg ◽  
N. L. Shaw ◽  
S. P. Hardegree
Keyword(s):  
Seed Germination ◽  
Big Sagebrush ◽  
Wyoming Big Sagebrush

Assemblage Patterns of Hymenoptera at Different Elevations of Gunung Datuk, Rembau

2017 ◽  
Vol 14 (2) ◽  
pp. 1 ◽  
Author(s):  
Noor Nasuha Abd Aziz ◽  
Siti Khairiyah Mohd Hatta ◽  
Idris Abd Ghani ◽  
Saiyid Jalaluddin Saiyid Shaifuddin
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
High Elevation ◽  
Significant Difference ◽  
Index Site ◽  
Evenness Index ◽  
Abundance And Diversity ◽  
Richness Index ◽  
Paired T Test ◽  
Malaise Traps

A study on abundance and diversity of Hymenoptera was conducted in Gunung Datuk, Rembau. Samplings were conducted from November 2014 to February 2015 using six Malaise traps. Three traps were placed at Site 1 at 700m height for high elevation and the remaining traps were placed at Site 2 at 200m height for low elevation. A total number of 221 Hymenopteran were collected which consist of nine families namely Ichneumonidae, Formicidae, Braconidae, Bethylidae, Evaniidae, Tiphiidae, Vespidae, Pompilidae and Apidae. In this study, 93 individuals were obtained from Site 1, comprising nine families and 43 morphospecies while 127 individuals were obtained from Site 2 with nine families and 45 morphospecies. Formicidae was the most dominant family collected from both sites with a total of 104 individuals while the least family recorded was Apidae with only one individual. Shannon’s Weiner Diversity Index (H’) showed Site 1 had the higher diversity value with H’ = 3.17 compared to Site 2 with value H’ = 3.12. For Evenness Index, Site 1 had higher value compared to Site 2 with E’ = 0.84 and E’ = 0.82 respectively. Moreover, for Margalef Richness Index, Site 1 recorded R’ = 9.24 while site two recorded R’ = 9.08 which concluded that Site 1 had higher species richness compared to Site 2. Paired t-test showed that both sites had no significant difference with p>0.05. Overall study showed that the diversity and abundance of Hymenoptera in Gunung Datuk were low since the value of H’ is less than 3.50.

Evoluzione della copertura vegetale in aree alpestri del Canton Ticino nel periodo 1971–2001 | Evolution of Vegetation Cover in the Alpine Regions of Canton Tessin: 1971–2001

2004 ◽  
Vol 155 (7) ◽  
pp. 284-289 ◽  
Author(s):  
Pietro Stanga ◽  
Niklaus Zbinden
Keyword(s):  
Initial Conditions ◽  
Ground Cover ◽  
Climatic Conditions ◽  
Human Pressure ◽  
Aerial Photos ◽  
Alpine Regions ◽  
Subsequent Decrease ◽  
Site Fertility ◽  
Strong Expansion ◽  
Evolution Of Vegetation

The retrospective study based on aerial photos (1971–2001) of the Canton Tessin made it possible to measure and analyze the evolution of the vegetation of eleven Alpine zones. The analysis shows a strong expansion of the arborescent vegetation and, at the same time, a decrease in other forms of ground cover (bush, shrub, meadow and unproductive spaces). Analysis of the data gives rise to the conjecture that the strong evolutionary dynamism evidenced by the areas under investigation is a result of the vast clearings carried out in past centuries to create pastures. Following the subsequent decrease in human pressure, nature today is attempting to rebalance the level of the biomass. These processes manifest themselves in different ways and with various intensity, depending on the interaction of numerous factors (e.g. climatic conditions, site fertility, initial conditions, evolution of anthropological pressure, etc.).

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