scholarly journals Influencia de la actividad petrolera y la ganadería ovina en la cubierta del suelo en una región árida y semiárida de la Patagonia Argentina

2019 ◽  
Vol 45 (2) ◽  
pp. 661
Author(s):  
M.A. Buzzi ◽  
B.L. Rueter ◽  
L. Ghermandi ◽  
F. Maldonado
Keyword(s):  
Plant Communities ◽  
Mesh Size ◽  
Ground Cover ◽  
Bare Soil ◽  
Edge Density ◽  
Oil Exploitation ◽  
Multi Temporal ◽  
Effective Mesh Size ◽  
Landscape Units ◽  
Geographical Space

The Geography has provided the greatest theoretical body for the study of the configurations that occur over the geographical space. The generation of cartography that represents ground cover is one of the most important uses of remote sensing. Polygons were selected, with oil and livestock activity, in the landscape units: coastal canyons, plateaus and western valleys. The polygons were used to evaluate multi-temporal changes in land cover and plant communities over a period of 15 years. Supervised classifications and analysis of landscape metrics were made to examine the possible causes of these changes by comparing: i) polygons without oil or livestock activity (control), ii) polygons with oil and livestock activity, iii) polygons with oil activity and without livestock activity, and iv) polygons without oil activity and livestock activity. The results obtained indicated that the density of patches, the total edge, the edge density and the division index of the fragments increased in the three landscape units, between 2001 and 2016. The contagion index, however, decreased. An increase in bare soil was observed in the plateaus and in the western valleys, with a regression of the dominant plant communities. The density of patches in the sites without disturbance was the lowest, and in the sites with both disturbances acting simultaneously was maximum. In the sites without disturbance the effective mesh size was maximum, while in the sites with some disturbance it was smaller. When analyzing the effect of the disturbance on the elements of the landscape it was observed that the presence of the disturbance generates the highest density of patches and the minimum connectivity. The results show that there was a process of fragmentation in the coverage of the soil directed by the oil exploitation and sheep farming, which decrease the size of the patches and, therefore, the density of the same per unit area.

scholarly journals The Extent of Infrastructure Causing Fragmentation in the Hydrocarbon Basin in the Arid and Semi-Arid Zones of Patagonia (Argentina)

2019 ◽  
Vol 11 (21) ◽  
pp. 5956
Author(s):  
Buzzi ◽  
Rueter ◽  
Ghermandi ◽  
Lasaponara
Keyword(s):  
Principal Component ◽  
Mesh Size ◽  
Oil Production ◽  
Landscape Fragmentation ◽  
Arid Zones ◽  
Effective Mesh Size ◽  
The Mean ◽  
Patch Density ◽  
Landscape Units ◽  
Semi Arid

Fragmentation is a disruption in the connectivity of landscapes. The aims of this paper are (i) to quantitatively assess the fragmentation rates in three landscape units located in a hydrocarbon basin, and (ii) to model their behavior between 2001 and 2013 using landscape metrics at different scales of resolution. The following metrics were selected using principal component analysis (PCA): The Clumpiness Index (CLUMPY), patch density (PD), perimeter-area fractal dimension (PAFRAC) and effective mesh size (MESH). Results from our investigations pointed out that hydrocarbon activity increased the fragmentation at the sites. In particular, the CLUMPY index increased in all three landscape units, the average of PD decreased from 60 to 14 patches per 100 hectares, whereas the mean of MESH was quite constant, however, due to oil production, it decreased mainly in the coastal valleys. Finally, the PAFRAC also decreased at sites with oil production, being more evident in the plateau and coastal canyons. As a whole, outputs from our analyses clearly pointed out that the monitoring of landscape fragmentation trends in arid and semi-arid zones can be successfully achieved using metrics derived from satellite spectral information.

scholarly journals Assessment of Tuscany Landscape Structure According to the Regional Landscape Plan Partition

2021 ◽  
Vol 13 (10) ◽  
pp. 5424
Author(s):  
Martina Venturi ◽  
Francesco Piras ◽  
Federica Corrieri ◽  
Beatrice Fiore ◽  
Antonio Santoro ◽  
...  
Keyword(s):  
Landscape Structure ◽  
Agricultural Landscapes ◽  
Edge Density ◽  
Regional Government ◽  
Land Uses ◽  
Landscape Mosaic ◽  
Landscape Complexity ◽  
Economic Role ◽  
Patch Density ◽  
Landscape Units

The landscape is considered a strategic asset by the Tuscan regional government, also for its economic role, meaning that a specific Landscape Plan has been developed, dividing the region into 20 Landscape Units and representing the main planning instrument at the regional level. Following the aims of the Landscape Plan and the guidelines of the European Landscape Convention, it is necessary to develop an adequate assessment of the landscape, evaluating the main typologies and their characteristics. The aim of this research is to carry out an assessment of the landscape diversity in Tuscany based on 20 study areas, analyzing land uses and landscape mosaic structures through the application of landscape metrics: number of land uses, mean patch size (MPS), Hill’s diversity number, edge density (ED), patch density (PD), land use diversity (LUD). The results highlight a correlation between the landscape typologies (forest, agricultural, mixed, periurban) and the complexity of the landscape structure, especially in relation to MPS and PD, while the combination of PD and LUD calculated on the basis of a hexagonal grid allows obtaining landscape complexity maps. Despite the phenomena of reforestation and urban sprawl of recent decades, Tuscany still preserves different landscape typologies characterized by a good level of complexity. This is particularly evident in mixed landscapes, while agricultural landscapes have a larger variability because of different historical land organization forms. The methodology applied in this study provided a large amount of data about land uses and the landscape mosaic structure and complexity and proved to be effective in assessing the landscape structure and in creating a database that can represent a baseline for future monitoring.

scholarly journals INFLUÊNCIA DA COBERTURA MORTA NA EVAPOTRANSPIRAÇÃO, COEFICIENTE DE CULTIVO E EFICIÊNCIA DE USO DE ÁGUA DO MILHO CULTIVADO EM CERRADO

Irriga ◽  
2018 ◽  
Vol 21 (2) ◽  
pp. 352
Author(s):  
HIPÓLITO MURGA-ORRILLO ◽  
WELLINGTON FARIAS ARAUJO ◽  
CARLOS ABANTO RODRIGUEZ ◽  
RICARDO MANUEL BARDALES LOZANO ◽  
ROBERTO TADASHI SAKAZAKI ◽  
...  
Keyword(s):  
Zea Mays ◽  
Water Use Efficiency ◽  
Water Use ◽  
Water Consumption ◽  
Irrigation Management ◽  
Crop Coefficient ◽  
Ground Cover ◽  
Bare Soil ◽  
Crop Cycle ◽  
Use Efficiency

INFLUÊNCIA DA COBERTURA MORTA NA EVAPOTRANSPIRAÇÃO, COEFICIENTE DE CULTIVO E EFICIÊNCIA DE USO DE ÁGUA DO MILHO CULTIVADO EM CERRADO HIPÓLITO MURGA-ORRILLO1; WELLINGTON FARIAS ARAÚJO2; CARLOS ABANTO-RODRIGUEZ3; ROBERTO TADASHI SAKAZAKI4; RICARDO MANUEL BARDALES-LOZANO5 E ANA ROSA POLO-VARGAS6 1Engenheiro Agrônomo, Prof. Auxiliar, Universidad Nacional Autónoma de Chota, (UNACH), Jr. Gregorio Malca Nº 875- Campus Colpa Matara, Chota, Perú. [email protected] Agrônomo, Prof. Dr. Associado da UFRR/CCA, Boa Vista, RR. [email protected] Florestal, Investigador no Instituto de Investigaciones de la Amazonía Peruana, Carretera Federico Basadre, Km 12,400, Yarinacocha, Ucayali, Perú. [email protected] Agrônomo, Doutorando na UFRR/CCA, Boa Vista, RR. [email protected] Agrônomo, Doutorando na UFRR/Bionorte, Boa Vista, RR. [email protected] Agrônoma, Graduada na Universidad Nacional de Cajamarca, (UNC), Av. Atahualpa Nº 1050- Carretera Cajamarca-Baños del Inca, Cajamarca, Perú. [email protected]  1 RESUMOA irrigação consome grande quantidade de água, sendo importante um adequado manejo da cultura para minimizar esse consumo, maximizando a produção. No intuito de obter informações para o manejo da irrigação, objetivou-se com o presente trabalho determinar a evapotranspiração da cultura (ETc), o coeficiente de cultivo (Kc) e a eficiência do uso de água (EUAg) da cultura de milho, em solo com e sem cobertura, durante os diferentes estádios de desenvolvimento, utilizando lisímetros de drenagem. O experimento foi conduzido no campus Cauamé da Universidade Federal de Roraima, entre 19/04/2014 e 07/08/2014, em Boa Vista, RR. A evapotranspiração de referência (ETo) foi estimada pelo método de Penman-Monteith FAO. Os resultados da ETc do milho, durante o ciclo da cultura, em solo sem e com cobertura foram de 421,5 e 351,0 mm, respectivamente. As médias diárias de ETc foram de 4,1 mm dia-1 para solo sem cobertura e 3,4 mm dia-1 para solo com cobertura. A cobertura do solo propiciou valores diferentes de Kc's para o milho, nos mesmos estádios, em comparação aos Kc’s do solo descoberto. Para o solo descoberto, os Kc’s observados para os estádios fenológicos I, II, III, e IV, foram de 0,40; 0,84; 1,59 e 0,81, respectivamente. Já para solo com cobertura, os Kc’s pelos mesmos estádios em menção foram 0,28; 0,64; 1,49 e 0,48, respectivamente. A EUAg para solo com cobertura foi 1,77 kg m-3 e para solo sem cobertura foi 1,65 kg m-3. Estes resultados mostram que a cobertura morta no solo influenciou no consumo hídrico do milho durante todo seu ciclo. Palavras-chave: Zea mays. Irrigação. Solo coberto. Consumo hídrico.  MURGA-ORRILLO, H.; ARAÚJO, W. F.; ABANTO-RODRIGUEZ C.; SAKAZAKI, R. T.; BARDALES-LOZANO R. M.; POLO-VARGAS, A. R.MULCH INFLUENCE ON EVAPOTRANSPIRATION, CROP COEFFICIENT AND WATER USE EFFICIENCY OF CORN GROWN IN THE SAVANNAH   2 ABSTRACTIrrigation consumes large amounts of water, and minimizing consumption and maximizing the production are  important to a proper crop management . In order to obtain information for irrigation management, the aim of the present study was to determine evapotranspiration (ETc),  crop coefficient (Kc) and  water use efficiency (WUE) of maize grown in soil with and without cover, during the various stages of development, using drainage lysimeters. The experiment was conducted in Cauamé campus of the Federal University of Roraima, from 19/04/2014 to 08/07/2014, in Boa Vista, RR. The reference evapotranspiration (ETo) was estimated by the Penman-Monteith method. The results of the corn ETc during the crop cycle in soil with and without coverage were 421.5 and 351.0 mm, respectively. The daily average of ETc were 4.1 mm day-1 for bare soil and 3.4 mm day-1 for soil with cover. The ground cover led to different values of Kc's for corn in the same stages as compared to Kc's from the bare ground. For bare soil, the Kc's observed for the phenological stages I, II, III, and IV were 0.40; 0.84; 1.59 and 0.81, respectively. As for covered soil, the Kc's in the same stadiums mentioned were 0.28; 0.64; 1.49 and 0.48, respectively. The WUE to soil with cover was 1.77 kg m-3 and ground without cover was 1.65 kg m-3. These results show that  soil mulching influenceS maize water consumption throughout its cycle. Keywords: Zea mays. Irrigation. Ground covered. Water consumption.

scholarly journals Plant communities of the Karkas Hunting-Prohibited Region, Isfahan-Iran

2008 ◽  
Vol 54 (No. 8) ◽  
pp. 347-358
Author(s):  
S.J. Khajeddin ◽  
H. Yeganeh
Keyword(s):  
Plant Communities ◽  
Random Sampling ◽  
Dominant Species ◽  
Sampling Method ◽  
Bare Soil ◽  
Cluster Analyses ◽  
Isfahan Province ◽  
Biogeographic Region ◽  
The Impact ◽  
Interesting Area

The Karkas mountainous region is a very interesting area for its big game wildlife and rare species in the Irano-Touranian biogeographic region. It is essential to study the plant communities and the impact of environmental factors, to protect and rehabilitate these ecosystems. The studied region is located in the Isfahan province, central Iran, with the area of about 92 100 ha. The aim of the study was to identify the plant communities of the Karkas Hunting-Prohibited Region. Vegetation cover was sampled using a stratified random sampling method and the entities were preliminarily segmented with the physiognomic-floristic-ecologic method. 10 × 10 m quadrates (100 m<sup>2</sup>) were used to estimate the species cover, litter, stone, gravel and bare soil percentages. Plant communities were classified using cluster analyses and denderogram construction. The results confirmed the importance of the climatic and topographic factors that affect the establishment of the plant communities. Plant habitats in the region are mosaics and cause ecoton formations, so diversities in species combinations increase. The species diversity of the communities was measured using the Shannon coefficient; it varied from 2.26 to 0.39. According to cluster analyses, there are 15 different plant communities, but when the second dominant species were considered, some communities were further divided into sub-communities.

scholarly journals Methane emission by plant communities in an alpine meadow on the Qinghai-Tibetan Plateau: a new experimental study of alpine meadows and oat pasture

2009 ◽  
Vol 5 (4) ◽  
pp. 535-538 ◽  
Author(s):  
Shiping Wang ◽  
Xiaoxia Yang ◽  
Xingwu Lin ◽  
Yigang Hu ◽  
Caiyun Luo ◽  
...  
Keyword(s):  
Experimental Study ◽  
Soil Temperature ◽  
Plant Communities ◽  
Alpine Meadow ◽  
Pore Space ◽  
Bare Soil ◽  
Chemical Mechanism ◽  
Limited Evidence ◽  
Growing Seasons ◽  
Water Filled Pore Space

Recently, plant-derived methane (CH 4 ) emission has been questioned because limited evidence of the chemical mechanism has been identified to account for the process. We conducted an experiment with four treatments (i.e. winter-grazed, natural alpine meadow; naturally restored alpine meadow eight years after cultivation; oat pasture and bare soil without roots) during the growing seasons of 2007 and 2008 to examine the question of CH 4 emission by plant communities in the alpine meadow. Each treatment consumed CH 4 in closed, opaque chambers in the field, but two types of alpine meadow vegetation reduced CH 4 consumption compared with bare soil, whereas oat pasture increased consumption. This result could imply that meadow vegetation produces CH 4 . However, measurements of soil temperature and water content showed significant differences between vegetated and bare soil and appeared to explain differences in CH 4 production between treatments. Our study strongly suggests that the apparent CH 4 production by vegetation, when compared with bare soil in some previous studies, might represent differences in soil temperature and water-filled pore space and not the true vegetation sources of CH 4 .

Post-fire seeding with ryegrass: implications for understorey plant communities and overall effectiveness

2015 ◽  
Vol 24 (4) ◽  
pp. 518
Author(s):  
Melissa A. McMaster ◽  
Andrea Thode ◽  
Michael Kearsley
Keyword(s):  
Ponderosa Pine ◽  
Plant Cover ◽  
Ground Cover ◽  
Plant Invasions ◽  
Bare Soil ◽  
Italian Ryegrass ◽  
Exotic Plant ◽  
Vegetative Cover ◽  
High Severity ◽  
Significant Difference

Seeding following high-severity wildfires is motivated by the goals of increasing vegetative cover and decreasing bare soil in order to minimise soil erosion and exotic plant invasions. We compared the ground cover and vegetation response of seeded versus non-seeded areas located in the Warm Fire in northern Arizona, where post-fire seeding treatments with Italian ryegrass (Lolium perenne spp. multiflorum (L.)) were conducted in 4000 ha of high-severity burned areas. Over the course of the study, we observed no significant difference between seeded and non-seeded plots in percentage of bare soil, total vegetative cover or exotic plant cover. However, there were significant differences in plant community composition as revealed by PERMANOVA and Indicator Species Analysis. Two years post-fire there were significantly fewer ponderosa pine seedlings, and the cover of annual and biennial forbs was significantly lower in plots that were seeded with Italian ryegrass. In the third year, the cover of native bunch grasses was significantly lower in seeded plots. The differences we observed may be due to differences in pre-existing vegetation composition because of the geographic separation of the plots across the landscape. Our results illustrate the ineffectiveness of post-fire seeding in achieving the goals of increasing vegetative cover and decreasing the invasion of non-native plants, and we suggest that alternative post-fire remediation should be considered in the future.

scholarly journals Distinguishing Photosynthetic and Non-Photosynthetic Vegetation: How Do Traditional Observations and Spectral Classification Compare?

2019 ◽  
Vol 11 (21) ◽  
pp. 2589 ◽  
Author(s):  
Claire Fisk ◽  
Kenneth Clarke ◽  
Steven Delean ◽  
Megan Lewis
Keyword(s):  
Full Range ◽  
Significant Proportion ◽  
Ground Cover ◽  
Bare Soil ◽  
Remotely Sensed ◽  
Spectral Unmixing ◽  
Field Methodology ◽  
Wheat Leaves ◽  
Vegetation Samples

Remotely sensed ground cover maps are routinely validated using field data collected by observers who classify ground cover into defined categories such as photosynthetic vegetation (PV), non-photosynthetic vegetation (NPV), bare soil (BS), and rock. There is an element of subjectivity to the classification of PV and NPV, and classifications may differ between observers. An alternative is to estimate ground cover based on in situ hyperspectral reflectance measurements (HRM). This study examines observer consistency when classifying vegetation samples of wheat (Triticum aestivum var. Gladius) covering the full range of photosynthetic activity, from completely senesced (0% PV) to completely green (100% PV), as photosynthetic or non-photosynthetic. We also examine how the classification of spectra of the same vegetation samples compares to the observer results. We collected HRM and photographs, over two months, to capture the transition of wheat leaves from 100% PV to 100% NPV. To simulate typical field methodology, observers viewed the photographs and classified each leaf as either PV or NPV, while spectral unmixing was used to decompose the HRM of the leaves into proportions of PV and NPV. The results showed that when a leaf was ≤25% or ≥75% PV observers tended to agree, and assign the leaf to the expected category. However, as leaves transitioned from PV to NPV (i.e., PV ≥ 25% but ≤ 75%) observers’ decisions differed more widely and their classifications showed little agreement with the spectral proportions of PV and NPV. This has significant implications for the reliability of data collected using binary methods in areas containing a significant proportion of vegetation in this intermediate range such as the over/underestimation of PV and NPV vegetation and how reliably this data can then be used to validate remotely sensed products.

scholarly journals Comparison of Hyperspectral Versus Traditional Field Measurements of Fractional Ground Cover in the Australian Arid Zone

2019 ◽  
Vol 11 (23) ◽  
pp. 2825 ◽  
Author(s):  
Claire Fisk ◽  
Kenneth Clarke ◽  
Megan Lewis
Keyword(s):  
Spatial Scale ◽  
Arid Zone ◽  
Ground Cover ◽  
Field Measurements ◽  
Bare Soil ◽  
Point Sampling ◽  
Calibration And Validation ◽  
Fractional Cover ◽  
In Situ Methods

The collection of high-quality field measurements of ground cover is critical for calibration and validation of fractional ground cover maps derived from satellite imagery. Field-based hyperspectral ground cover sampling is a potential alternative to traditional in situ techniques. This study aimed to develop an effective sampling design for spectral ground cover surveys in order to estimate fractional ground cover in the Australian arid zone. To meet this aim, we addressed two key objectives: (1) Determining how spectral surveys and traditional step-point sampling compare when conducted at the same spatial scale and (2) comparing these two methods to current Australian satellite-derived fractional cover products. Across seven arid, sparsely vegetated survey sites, six 500-m transects were established. Ground cover reflectance was recorded taking continuous hyperspectral readings along each transect while step-point surveys were conducted along the same transects. Both measures of ground cover were converted into proportions of photosynthetic vegetation, non-photosynthetic vegetation, and bare soil for each site. Comparisons were made of the proportions of photosynthetic vegetation, non-photosynthetic vegetation, and bare soil derived from both in situ methods as well as MODIS and Landsat fractional cover products. We found strong correlations between fractional cover derived from hyperspectral and step-point sampling conducted at the same spatial scale at our survey sites. Comparison of the in situ measurements and image-derived fractional cover products showed that overall, the Landsat product was strongly related to both in situ methods for non-photosynthetic vegetation and bare soil whereas the MODIS product was strongly correlated with both in situ methods for photosynthetic vegetation. This study demonstrates the potential of the spectral transect method, both in its ability to produce results comparable to the traditional transect measures, but also in its improved objectivity and relative logistic ease. Future efforts should be made to include spectral ground cover sampling as part of Australia’s plan to produce calibration and validation datasets for remotely sensed products.

scholarly journals Potential Invasiveness for Eucalyptus Species in Florida

2015 ◽  
Vol 8 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Kimberly A. Lorentz ◽  
Patrick J. Minogue
Keyword(s):  
Plant Communities ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Bare Soil ◽  
Bioenergy Crops ◽  
Eucalyptus Species ◽  
Buffer Zones ◽  
Forest Road ◽  
Central Florida ◽  
Perennial Plant

AbstractTo assess the potential invasiveness of common eucalyptus species planted for pulpwood, mulch wood or bioenergy crops, field surveys of eucalyptus seedling recruitment were conducted in north and central Florida locations within seed bearing eucalyptus stands and in the proximate plant communities where seed dispersal may occur. Plant communities included non-grazed pasture, intensively site-prepared forestland, abandoned forest road and upland mixed pine- hardwood forest. No eucalyptus seedlings were found in any of the 310 1-m2 survey plots across the two locations. Second, seed addition studies were conducted to determine the relative potential for seedling emergence and survival among Eucalyptus amplifolia, E. camaldulensis and E. grandis added into plots at two seed densities, under disturbed and nondisturbed conditions, in the understory of the eucalyptus stands and in each of the aforementioned proximate plant communities. Overall, the probability of emergence of added seed was very low (P = 0.0 to 0.0032), and seed density effects were not significant. Emergence was significantly greater in disturbed conditions compared to nondisturbed conditions for seedlings originating from natural seed rain from the eucalyptus canopy in central Florida. The amount of time that seedlings survived was greater for E. camaldulensis compared to the other species but no seedlings survived more than 13 wk. These data indicate that under specific favorable conditions, eucalyptus seedlings may establish within or proximate to planted stands, but the overall level of invasiveness demonstrated by E. amplifolia and E. grandis is low for north or central Florida. The demonstrated role of disturbance in facilitating eucalyptus seedling recruitment suggests that a stable perennial plant community (native grasses) should be established instead of bare soil buffer zones to mitigate spread.

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