Land Vegetation Type Research Articles

Relationship of Land Cover Heterogeneity and Insecticide Use with Arthropod Community Structure in Rice Agroecosystems

Rice agroecosystems generally experience two kinds of environmental stresses, i.e., a decrease in the heterogeneity of land vegetation types due to the development of settlements in the border zone and the excessive use of insecticides. Both of these factors are known to affect the structure of the arthropod community in rice agroecosystems. However, studies related to the effects of these two stresses in shaping the structure of arthropod communities have not been widely carried out, especially during the planting period in the rainy season. This study aims toanalyze the relationship between land cover heterogeneity and insecticide use with the taxonomic and functional diversity of arthropods in thealpha, beta, and gamma dimensions. The study was conducted during the rainy season (October–March) on four rice agroecosystem sites in Bandung, West Java. Data was collected 30 and 50 days after planting (DAP). Arthropod samples were identified, and their taxonomic andfunctional diversity was calculated using the Shannon entropy formula (D). In general, land cover heterogeneity was positively correlated withthe value of arthropod taxonomic and functional diversity, especially in the early vegetative phase of rice plants (30 DAP). In con- trast,insecticides (g/m2) were negatively correlated with the value of arthropod diversity. The composition of arthropod species locally was relativelythe same except in the rice agroecosystem with the lowest land cover heterogeneity and the highest use of insecticides. Additionally, thecoefficient value of the insecticide variable has more influence on the value of arthropod diversity than the variable coefficient of land coverheterogeneity.

Vertical accuracy of open-source remote sensing data (AW3D30, TanDEM-X, ATLAS) for understory terrain estimation

Understory terrain is an important fundamental indicator for monitoring changes in forest ecosystems. However, in-depth analysis of the accuracy of existing international open-source DEM products is still lacking for understory environments. The DEM data produced by Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) carries an advanced topographic LiDAR altimeter system (ATLAS) that contains elevation information of the ground surface as well as features such as the vegetation above. It can reflect the elevation of the ground surface, including the part obscured by vegetation or canopy, and can be better used to monitor changes in ground surface elevation. However, few existing studies have been analyzed the accuracy of open-source DEM products (include ATLAS, AW3D30 DEM, and TanDEM-X data) for estimating the ground in understory environments. Therefore, this study selected Aiken County, Cook Inlet, and Yucatan as study areas to evaluate ICESat-2/ATLAS data, AW3D30 DEM and TanDEM-X data using the airborne G-LiHT system’s post-processing DTM. The study also quantitatively evaluated the influence of slope, aspect, and land vegetation type on elevation accuracies of different open-source DEM products. The experimental results showed that the ATLAS data at the footprint scale produced more accurate evaluation indicators than the AW3D30 DEM and TANDEM-X data products. The average evaluation indicator R 2 was 0.98, RMSE was 1.44 m, and STD was 1.25 m. The results showed that ATLAS can be used as validation data to evaluate the accuracy of open-source DEM in estimating the vertical direction. At the regional scale, AW3D30 was the most robust and had the most stable performance in most of the tests (R 2 is 0.95, RMSE is 6.37 m and STD is 5.02 m) and is therefore the best choice for research on understory terrain. Slope had a greater impact on the accuracy of data estimation compared to aspect and surface vegetation type. The difference in RMSE for estimating forest understory terrain was 3.11 m for ATLAS products, 29.37 m for AW3D30 DEM data and 54.26 m for TanDEM-X data over the different slopes.

Glossina pallidipes Density and Trypanosome Infection Rate in Arba Minch Zuria District of Gamo Zone, Southern Ethiopia.

Background African trypanosomosis is a disease of both animals and humans resulting from infection with parasitaemic protozoa of the genus Trypanosoma transmitted mainly by the tsetse flies (Glossina species). The disease has been reported in different parts of the country. However, information on the apparent density and trypanosome infection rates of the vectors is very limited in the Southern part of Ethiopia. Therefore, this study was conducted to estimate the apparent density, infection rate of trypanosomes in Glossina pallidipes, and the trypanosome species involved in Arba Minch Zuria district of Southern Ethiopia. Methods A cross-sectional study was conducted from January to June 2018 in two purposely selected kebeles of Arbaminch Zuria district and in the escarpments of Nech Sar National Park of Southern Ethiopia. For entomological survey, a total of 40 standard NGU traps were deployed around the watering and grazing areas. A total of 300 fresh Glossina pallidipes were examined for trypanosome infection using a dissection procedure as described by the FAO Training manual for tsetse control personnel. Results The study revealed the presence of only one Glossina species, known as Glossina pallidipes, and biting flies including Stomoxys and Tabanus. A total of 2176 flies were caught of which 1803 (82.86%) belong to Glossina pallidipes and the remaining 373 (17.14%) were biting flies. The overall apparent density of Glossina pallidipes and biting flies in the study area were 15.03 fly/trap/day (F/T/D) and 3.11 F/T/D, respectively. Relatively higher Glossina pallidipes and biting flies, respectively, were caught in a wood-grass land (15.87 F/T/D and 3.69 F/T/D) and riverine forest (15.13 F/T/D and 3.42 F/T/D) than bush land vegetation types (13.87 F/T/D and 1.76 F/T/D). The overall trypanosome infection rate of Glossina pallidipes was 17.67% (53/300). Two trypanosome species, namely, Trypanosoma congolense (66.04%) and Trypanosoma vivax (33.96%), were responsible for Glossina pallidipes infection in the study area. Trypanosome infection rate was significantly higher in female G. pallidipes than in male (OR = 3.39, 95%CI = 1.53‐7.52). Significantly, higher trypanosome infection rate was observed in flies older than 20 days (OR = 2.5, 95%CI = 1.12‐5.56) and in hunger stage 1 flies (OR = 14.24, 95%CI = 4.01‐50.59). Glossina pallidipes infection was significantly higher in and around park grazing areas (OR = 3.41, 95%CI = 1.76‐6.6) and wood-grass land vegetation type (OR = 2.7, 95%CI = 1.2‐6.5). Conclusion The current study revealed high apparent density and trypanosome infection in Glossina pallidipes in Arba Minch Zuria district of Southern Ethiopia. So, this study warrants the need for strengthening both vector and parasite control strategies in the study area.

Identification of Peat Profile, Physicochemical Properties and Microstructures on Different Peat Soil Vegetation Types

Peat commonly known as highly organic soil, is a key issue at tropical and coastal infrastructure building. As a result, understanding the peat's characteristics is critical. To investigate the characteristics of several peats in Sabah is the purpose of this study. For this study, peat samples were taken from two different locations in the Beaufort Sabah, namely Klias and Lumadan, with different land vegetation types. Field work and laboratory testing were aimed to figure out the degree of humification and peat depth, as well as the physical and chemical properties of the peat. In addition, EDX and SEM tests were conducted to study the peat's chemical composition and its microstructural characteristics. The outcome shows that Klias and Lumadan samples are under classification of hemic (pseudo-fibrous) peat, which displays H6 to H7 on the von Post scale, indicating an intermediate degree of breakdown. Both research sites show different peat depths of 4 and 4.5m, respectively. The moisture content, organic content, fibre content, specific gravity, liquid limit, and acidity of peat from Klias to Lumadan sites are found to be different. Chemical composition shows that the peat sample in Klias contains more elements of carbon compared to the Lumadan sample. The SEM result of Klias peat samples is made up of fibres that are woody, porous in nature and shows a little looser fibric arrangement. In contrast, the SEM result for Lumadan samples are lack on organic matter and fibre in soil, shows flaky granular nature and low quantity of void pores than the Klias sample. In this study, the SEM results are used to support the findings of the field and laboratory tests.

The Analysis of Tree Species Distribution Information Extraction and Landscape Pattern Based on Remote Sensing Images

The forest ecosystem is the largest land vegetation type, which plays the role of unreplacement with its unique value. And in the landscape scale, the research on forest landscape pattern has become the current hot spot, wherein the study of forest canopy structure is very important. They determines the process and the strength of forests energy flow, which influences the adjustments of ecosystem for climate and species diversity to some extent. The extraction of influencing factors of canopy structure and the analysis of the vegetation distribution pattern are especially important. To solve the problems, remote sensing technology, which is superior to other technical means because of its fine timeliness and large-scale monitoring, is applied to the study. Taking Lingkong Mountain as the study area, the paper uses the remote sensing image to analyze the forest distribution pattern and obtains the spatial characteristics of canopy structure distribution, and DEM data are as the basic data to extract the influencing factors of canopy structure. In this paper, pattern of trees distribution is further analyzed by using terrain parameters, spatial analysis tools and surface processes quantitative simulation. The Hydrological Analysis tool is used to build distributed hydrological model, and corresponding algorithm is applied to determine surface water flow path, rivers network and basin boundary. Results show that forest vegetation distribution of dominant tree species present plaque on the landscape scale and their distribution have spatial heterogeneity which is related to terrain factors closely. After the overlay analysis of aspect, slope and forest distribution pattern respectively, the most suitable area for stand growth and the better living condition are obtained.

Habitat Mapping and Quality Assessment of NATURA 2000 Heathland Using Airborne Imaging Spectroscopy

Appropriate management of (semi-)natural areas requires detailed knowledge of the ecosystems present and their status. Remote sensing can provide a systematic, synoptic view at regular time intervals, and is therefore often suggested as a powerful tool to assist with the mapping and monitoring of protected habitats and vegetation. In this study, we present a multi-step mapping framework that enables detailed NATURA 2000 (N2000) heathland habitat patch mapping and the assessment of their conservation status at patch level. The method comprises three consecutive steps: (1) a hierarchical land/vegetation type (LVT) classification using airborne AHS imaging spectroscopy and field reference data; (2) a spatial re-classification to convert the LVT map to a patch map based on life forms; and (3) identification of the N2000 habitat type and conservation status parameters for each of the patches. Based on a multivariate analysis of 1325 vegetation reference plots acquired in 2006–2007, 24 LVT classes were identified that were considered relevant for the assessment of heathland conservation status. These labelled data were then used as ground reference for the supervised classification of the AHS image data to an LVT classification map, using Linear Discriminant Analysis in combination with Sequential-Floating-Forward-Search feature selection. Overall classification accuracies for the LVT mapping varied from 83% to 92% (Kappa ≈ 0.82–0.91), depending on the level of detail in the hierarchical classification. After converting the LVT map to a N2000 habitat type patch map, an overall accuracy of 89% was obtained. By combining the N2000 habitat type patch map with the LVT map, two important conservation status parameters were directly deduced per patch: tree and shrub cover, and grass cover, showing a strong similarity to an independent dataset with estimates made in the field in 2009. The results of this study indicate the potential of imaging spectroscopy for detailed heathland habitat characterization of N2000 sites in a way that matches the current field-based workflows of the user.

Ethnobotanical study of wild edible plants in Derashe and Kucha Districts, South Ethiopia

The study discussed ethnobotany of and threats to wild edible plants in Derashe and Kucha Districts, South Ethiopia. Semi-structured interview, field observation, group discussion, market survey, and pair wise ranking were employed to gather ethnobotanical data. The information was collected from informants of three ethnic groups namely, Kusume, Derashe and Gamo people. The study documented 66 edible plant species belonging to 54 genera and 34 families. Of the reported edibles, 83.3% have more than one use categories. Food, medicine, construction/technology, and fuel wood had contributed 79% of the total uses. Of the recorded wild edible plant species, 78.8% were reported to be edible both in normal and food shortage times. Procurement and use of most edibles were found to be age and gender specific. However, species use under various use categories does not vary among the communities (X2 = 3.89, df = 6, α = 0.05 and 1-α = 12.6). The study showed that the majority (62.1%) of the species were collected from wooded grassland/or bush land vegetation type. Pair wise ranking results indicated that agricultural expansion, over stocking/overgrazing, fuel wood collection, and uncontrolled fire setting as principal threats to wild edible plants in the study areas. The findings suggest that (i) Public awareness and community based management need to be encouraged at all levels in order to overcome the threats; (ii) further investigation into nutritional properties of all the species reported; and (iii) Since the species are also nutraceutical, study on the pharmacological attributes would help to understand their medicinal applications. Furthermore, urgent collection of germplasm from areas under human pressure is recommended.

A regional climate study of Central America using the MM5 modeling system: results and comparison to observations

The Mesoscale Modeling system, version 3.6 (MM5) regional modeling system has been applied to Central America and has been evaluated against National Oceanic and Atmospheric Administration/National Climatic Data Center (NOAA/NCDC) daily observations and the Global Precipitation Climatology Project (GPCP) precipitation data. We compare model results and observations for 1997 and evaluate various climate parameters (temperature, wind speed, precipitation and water vapor mixing ratio), emphasizing the differences within the context of the station dependent geographical features and the land use (LU) categories. At 9 of the 16 analyzed stations the modeled temperature, wind speed and vapor mixing ratio are in agreement with observations with average model-observation differences consistently lower than 25%. MM5 has better performance at stations strongly impacted by monsoon systems, regions typified by low topography in coastal areas and areas characterized by evergreen, broad-leaf and shrub land vegetation types. At four stations the model precipitation is about a factor of 3–5 higher than the observations, while the simulated wind is roughly twice what is observed. These stations include two inland stations characterized by croplands close to water bodies; one coastal station in El Salvador adjacent to a mountain-based cropland area and one station at sea-level. This suggests that the model does not adequately represent the influence of topographic features and water bodies close to these stations. In general, the model agrees reasonably well with measurements and therefore provides an acceptable description of regional climate. The simulations in this study use only two seasonal maps of land cover. The main model discrepancies are likely attributable to the actual annual cycle of land–atmosphere vapor and energy exchange that has a temporal scale of days to weeks. These fluxes are impacted by surface moisture availability, albedo and thermal inertia parameters. Copyright © 2006 Royal Meteorological Society.

Remote sensing and GIS-based techniques for the classification and monitoring of biotopes: Case examples for a wet grass- and moor land area in Northern Germany

This paper presents a case study for the application of integrated remote sensing and GIS data for the classification and monitoring of biotopes and habitats in a wet grass- and moor land area in a sub regional scale. The study covers the techniques for a detailed biotope classification, the use of object-based methods for base classification and monitoring, as well as the integration with the existing federal biotope- and land use mapping of Schleswig-Holstein in Northern Germany. Dual-date Landsat TM images from spring and summer and IRS-1C data are used for classification, pre-existing floristic vegetation maps as training data. Twenty two wet grass- and moor land vegetation types were separated by the detailed classification. The object-based classification was successfully applied in order to identify hot spots for an update of the biotope register. The results are evaluated using the federal biotope mapping, aerial photographs and detailed floristic mappings at the site ecological scale.

Landsat Computer-Aided Analysis Techniques for Range Vegetation Mapping

Landsat computer-aided analysis techniques were used to map the sagebrush-grass vegetation of northern Nevada. A final Landsat digial clacation resulted in 14spectral classes representing 8 range plant communities. Classification accuracy for all sample plots was 86.4%, with individual class accuracies ranging from 77.8 to 95.4%. Classification methods included supervised, unsupervised, and guided clustering techniques using a maximum likelihood classifier. Rangeland inventory techniques have been subject to question and controversy since the beginning of range management. The problems include cost, adequate trained manpower, the requirement to inventory vast areas and the obtaining of an adequate sample. Remote sensing techniques have often been suggested and promoted for doing basic range inventories. The repetitive availability, relatively low cost per unit area, and digitized format of the Landsat data make such information of potential interest to range managers. This study was designed to measure the success of Landsat computer-aided analysis techniques for range vegetation mapping in Northern Nevada. Landsat digital data has seen only limited application on rangeland despite its potential for providing large quantities of vegetation mapping data at reasonable cost. Resolution limitations of the digital data (.42 ha or approximately 1.12 acres) along with complexity, diversity, and heterogeneity of range vegetation have tended to discourage its use. Several researchers have evaluated the application of Landsat digital data for mapping range and arid land vegetation (Daus 1975, Maxwell 1976, Tueller et al. i978, Everitt et al. 1979, Todd et al. 1980, Everitt et al. 1981). Maxwell (1976) inventoried vegetation types, range condition, and green biomass on grasslands in Colorado using a supervised classification technique. He concluded that Landsat was a very useful inventory tool on grasslands. Tueller et al. (1978) used Landsat digital data to map various arid land vegetation types in Australia. Todd et al. (1980) classified various densities of pinyon-juniper on two different geologic types on the Shivwits Plateau in Arizona. Misclassification was the result of low canopy and high bare ground cover. Bonner and Morgart (1980) described an operational procedure for arid land vegetation inventories and the sampling units required for accurate classification. Recently Everitt et al. (1981) used digital pattern recognition techniques and a maximum likelihood ratio classification and found a highly significant correlation (r2= 0.997) between air-photo and computer-estimated area of 5 land use categories for a June Lanasat-2 scene. Conditions were not significant for an August overpass, suggesting the importance of selected dates to reduce misclassification. Brush, mountain shrub/juniper, conifer, meadow, rock or bare ground and water were readily identified on rangeland near Susanville, Calif. (Daus 1975). Classification problems occurred at ecotones and areas that contained mixes of vegetation types. Areas of low canopy cover were difficult to classify because of the spectral dominance of soil background. Sub-class classification problems Authors are graduate research fellow and professor, Division of Renewable Natural Resources, University of Nevada Reno. This manuscript is published with approval of the Director, Nevada Agriculture Experiment Station as Journal Series No. 568. Manuscript received June 21, 1982. occurred in the big sagebrush communities with high proportions of bitterbrush, rabbitbrush, and other sagebrush species.

Geographic reconnaissance of Western Australian Seashore vegetation

Field study of 32 sites along the Western Australian coast showed that pioneer vegetation includes 110 species in 40 angiosperm families. Less than 25 % are exotic, only 10 % are endemic, and the bulk are shared with the interior or with other coasts of Australia. Regional ranges and microdistributions, described from herbarium records and 50 sample transects, are diverse. Although unique in detail, species distributions show broadly coherent relationships between geographic origins and present habitat patterns. Sheltered intertidal shores have two discrete types of land vegetation. Mangroves, sea-dispersed outliers of a richer Indo-Malayan assemblage, form extensive estuarine forests on the tropical coast, where tidal ranges are large, and a few stands of one species occur along the temperate coast. Low-growing chenopods and similar halophytes, with major populations in saline interior basins, are scattered discontinuously along the coast in shallowly flooded tidal marshes. They are subject to no apparent climatic control within the region. Rocky coasts are even more disjunct and also lack any unique, autochthonous vegetation. Wet pockets in the spray zone bear ordinary salt marsh plants while dry rock shores and outcrops in the dunes have vegetation differing mainly quantitatively from neighboring sand areas. Open beaches and dunes offer the most extensive coastal habitats and bear the most complex vegetation. Species groups derived from different geographic sources are loosely segregated by zones parallel to the shore. Toward the rear of the active dunes, some plants are simply outrunners from the stabilized inland sand vegetation : these are important dune pioneers in the drier sectors. Generally, the active dune zone is dominated by species peculiar to it, some endemic but mostly shared with temperate coasts east of the study region. All are adapted to tolerate salt spray, sand blast, and other special habitat conditions. Sclerophylions shrubs predominate, grading into small trees on parts of the moister, tem~erate coasts. Prostrate succulents, rhizomatous grasses and sedges, and other types of evergreen perennials are minor components. The active dune vegetation is floristically richer and more regionally diversified towards its inner limits, the few species native to the outer dunes having comparatively wide coastwise ranges. On the outer faces of the foredunes and on the storm beach, the otherwise almost purely Australian sand vegetation is joined by exotics. Sea-dispersed paleotropical and pantropical beach vines, grasses, and other low-growing plants range along the north coast and a few penetrate beyond the tropic. A different, primarily inland group of old immigrants may have arrived indirectly via the arid interior to provide the extreme outpost vegetation of the drier coasts. Along the moister, temperate coasts, a belt seaward of the native dune vegetation is occupied by recently naturalized annuals and other low-growing herbs from temperate African and European beaches.Except close to roads and settlements, little recent modification of the coastal vegetation is evident. Some blowouts, particularly on the drier margin of the tem- perate region, may stem from dune burning, but generally the plant cover regenerates rapidly after fire.