Spatial prediction of brushtail possum (Trichosurus vulpecula) distribution using a combination of remotely sensed and field-observed environmental data

2013 ◽  
Vol 40 (7) ◽  
pp. 578 ◽  
Author(s):  
Thibaud Porphyre ◽  
Joanna McKenzie ◽  
Andrea E. Byrom ◽  
Graham Nugent ◽  
James Shepherd ◽  
...  
Keyword(s):  
Pest Control ◽  
Relative Abundance ◽  
Forest Cover ◽  
Remotely Sensed ◽  
Environmental Data ◽  
Effective Control ◽  
Brushtail Possum ◽  
Mean Annual Temperature ◽  
Trichosurus Vulpecula ◽  
Remotely Sensed Data

Context In New Zealand, the introduced brushtail possum, Trichosurus vulpecula, is a reservoir of bovine tuberculosis and as such poses a major threat to the livestock industry. Aerial 1080 poisoning is an important tool for possum control but is expensive, creating an ongoing need for ever more cost-effective ways of using this technique. Aims To develop geographic information system (GIS) models to better predict spatial variation in the distribution of unmanaged possum populations, to facilitate better targeting of control activities. Methods Relative abundance of possums and their distribution among habitat types were surveyed in a dry high-country area of the northern South Island. Two GIS-based models were developed to predict the relative abundance of possums on trap lines. The first model used remotely sensed (digital) environmental data; the second complemented the remotely sensed data with fine-scale habitat and topographic data collected on the ground. Key results Digital environmental factors and habitat features proved to be key predictors of relative possum abundance. In both GIS models, height above valley floor, presence of forest cover and mean annual temperature were the strongest predictors. Conclusions Predictive maps (projections) of relative possum abundance produced from these models can provide useful decision-support tools for pest-control managers, by enabling possum control to be targeted spatially. Implications Spatially targeted pest control could allow effective control activities for invasive species or disease vectors to be applied at a lower cost for the same benefit.

Aquatic and semi aquatic Hemiptera community of Sonebeel, the largest wetland of Assam, northeastern India

2018 ◽  
Vol 10 (13) ◽  
pp. 12792-12799
Author(s):  
Anupama Saha ◽  
Susmita Gupta
Keyword(s):  
Species Richness ◽  
Pest Control ◽  
Relative Abundance ◽  
Species Distribution ◽  
Diversity Indices ◽  
Environmental Data ◽  
Northeastern India ◽  
Ecological Roles

Aquatic and semiaquatic Hemiptera bugs play significant ecological roles, and they are important indicators and pest control agents.  Little information is currently available concerning its populations in southern Assam.  This study assessed hemipterans in four sites of Sonebeel, the largest wetland in Assam (3458.12 ha at full storage level), situated in Karimganj District.  The major inflow and outflow of the wetland are the rivers Singla and Kachua, respectively (the Kachua drains into the Kushiyara River).  Samples were trapped with pond nets and were seasonally recorded.  This study recorded a total of 28 species of aquatic and semiaquatic hemipterans belonging to 20 genera under nine families.  Population, geographical and environmental data (e.g., rainfall) were used to assess the relative abundance of species, species richness and different diversity indices, and species distribution. 

Landscape fragmentation

2010 ◽  
Author(s):  
Ned Horning ◽  
Julie A. Robinson ◽  
Eleanor J. Sterling ◽  
Woody Turner ◽  
Sacha Spector
Keyword(s):  
Forest Fragmentation ◽  
Landscape Metrics ◽  
Forest Cover ◽  
Remotely Sensed ◽  
Clear Understanding ◽  
Remotely Sensed Data ◽  
Deforestation Rates ◽  
Habitat Conversion ◽  
Conservation Organizations ◽  
Total Core Area

The country of Vietnam has long been recognized as an important region for biodiversity (Sterling et al. 2006). High-profile discoveries in the 1990s of many species new to science including large ones such as the Saola (Pseudoryx nghetinhensis), an 85 kg basal member of the cattle subfamily Bovinae and the first new genus of large land-dwelling mammal described since the okapi (Okapia johnstoni) in 1901, have focused the attention of national and international conservation organizations on Vietnam and surrounding countries in mainland Southeast Asia (Hurley et al. in prep.). Conservation action for these endemic, endangered species relies on a clear understanding of trends in habitat conversion. To track deforestation rates through time in Vietnam, Meyfroidt and Lambin (2008) combined remotely sensed data with landscape metrics such as number of patches, mean patch size, mean proximity index, and total core area index. They tested their analyses across a variety of land cover studies including those using Advanced Very High Resolution Radiometer (AVHRR), Landsat, SPOT, and MODIS data sources. They found that forest cover decreased nationally from the 1980s to the 1990s and then showed an increase between 1990 and 2000, due to plantation forests as well as natural forest regeneration. However, the effects of this forest transition on fragmentation metrics noted above differed across the country. For instance, in some places, such as central Vietnam where forest cover is relatively large and well connected, reforestation led to a decrease in forest fragmentation and secondary forests recovered rapidly. However in others, such as areas in the north where forest fragmentation dates back centuries and forests have therefore long been isolated, reforestation did not seem to have an impact on continued fragmentation and habitat loss. In this chapter we detail the importance of fragmentation and landscape metrics to ecology and conservation, outlining when and where remotely sensed data can help in these analyses. We then discuss a subset of fragmentation metrics and point to some challenges in processing fragmentation data. We provide examples of composition and connectivity metrics illuminated with examples from the remote sensing literature.

scholarly journals Tropical montane forests are a larger than expected global carbon store

2014 ◽  
Vol 11 (10) ◽  
pp. 2741-2754 ◽  
Author(s):  
D. V. Spracklen ◽  
R. Righelato
Keyword(s):  
Land Surface ◽  
Forest Cover ◽  
Slope Angle ◽  
Remotely Sensed ◽  
Data Sets ◽  
Remotely Sensed Data ◽  
Montane Forests ◽  
Tropical Montane Forests ◽  
Global Land ◽  
Steep Slopes

Abstract. Tropical montane forests (TMFs) are recognized for the provision of hydrological services and the protection of biodiversity, but their role in carbon storage is not well understood. We synthesized published observations (n = 94) of above-ground biomass (AGB) from forest inventory plots in TMFs (defined here as forests between 23.5° N and 23.5° S with elevations ≥ 1000 m a.s.l.). We found that mean (median) AGB in TMFs is 271 (254) t per hectare of land surface. We demonstrate that AGB declines moderately with both elevation and slope angle but that TMFs store substantial amounts of biomass, both at high elevations (up to 3500 m) and on steep slopes (slope angles of up to 40°). We combined remotely sensed data sets of forest cover with high resolution data of elevation to show that 75% of the global planimetric (horizontal) area of TMF are on steep slopes (slope angles greater than 27°). We used our remote sensed data sets to demonstrate that this prevalence of steep slopes results in the global land surface area of TMF (1.22 million km2) being 40% greater than the planimetric area that is the usual basis for reporting global land surface areas and remotely sensed data. Our study suggests that TMFs are likely to be a greater store of carbon than previously thought, highlighting the need for conservation of the remaining montane forests.

Dietary changes in response to population reduction in the possum Trichosurus vulpecula in New Zealand

2013 ◽  
Vol 40 (7) ◽  
pp. 561 ◽  
Author(s):  
Peter J. Sweetapple ◽  
Wendy A. Ruscoe ◽  
Graham Nugent
Keyword(s):  
New Zealand ◽  
Pest Control ◽  
Population Control ◽  
Stomach Contents ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Dietary Changes ◽  
Before And After ◽  
Per Capita ◽  
Indigenous Forest

Context Efforts to protect or restore degraded plant communities by population control of invasive herbivores frequently fail to achieve their goals. Aims We seek to quantify changes in diet of an introduced herbivore, the brushtail possum (Trichosurus vulpecula), following population control, and determine how these may contribute to variable responses in plant condition. Methods Stomach contents of possums from five areas of indigenous forest in northern New Zealand were analysed to measure diet before and after the application of possum control. Key results The contribution of fruit, and foliage of some early successional forest species, to total possum diet increased up to 27-fold following possum population control. This was accompanied by declines in consumption of the main pre-control possum foods (foliage from common canopy trees). Dietary changes were a combination of an immediate response to control (1 year) and a strengthening of these initial changes with increasing time since control. Conclusions Possums in the study areas changed diet following population control, from a diet dominated by foliage of common canopy tree species to one dominated by fruits, and foliage of uncommon early successional plants. Pest control instantaneously increased the per capita availability of all foods, and probably permitted absolute increases in some foods through plant recovery, enabling possums to substitute scarce, high-preference foods for abundant but less preferred canopy foliage. Implications Following control of a pest herbivore, dietary changes reduce benefits for the most vulnerable preferred plant foods, but enhance benefits for less favoured plants. Intense pest control can permit some recovery of highly preferred foods, despite increased per capita consumption of these foods by survivors of control.

scholarly journals Geospatial analysis-based approach for assessing urban forests under the influence of different human settlement extents in Ibadan city, Nigeria

2020 ◽  
Vol 12 (4) ◽  
pp. 959-971
Author(s):  
Oluwayemisi S. OLOKEOGUN ◽  
Abiodun O. OLADOYE ◽  
Oluwatoyin O. AKINTOLA
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Forest Cover ◽  
Urban Forest ◽  
Urban Forests ◽  
Remotely Sensed ◽  
Google Earth ◽  
Human Settlement ◽  
Remotely Sensed Data ◽  
The Status

Urban forests are an essential component of urban areas as they provide many environmental and social services that contribute to the quality of life in cities. Urban forests in most cities of Nigeria are gradually becoming bitty as a result of urbanization activities, thereby posing adverse effects. In this study, we assessed the changes in the urban forests cover under the influence of different human settlement (HS) extents across the urban area of Ibadan city using remotely sensed data. The pattern of change(s) in the urban forests cover over 20 years were examined by analysing and manipulating Landsat and Sentinel-2 datasets using Google Earth Engine, ArcGIS 10.1, and Erdas 2014 software. The extents of human settlement (for the year 2000, 2005, 2010, 2015, and 2020) were extracted (from Landsat datasets), analysed, and mapped to evaluate the status of the urban forests cover under different human settlement extents. The result reveals a substantial land cover changes within the urban area of Ibadan.  The urban forest cover decreased from 24.14% to 7.99%. Also, there is a significant decrease in the urban forests cover as a result of a substantial increase in human settlement extent (102,806 to 122,572 pixels). The study provides an opportunity to map the status of urban forest cover and extents of HS in a developing city using remotely sensed data and applications of GIS tools.

A knowledge-based approach for evaluadng forestry-map congruency with remotely sensed imagery

1988 ◽  
Vol 324 (1579) ◽  
pp. 447-456 ◽  
Keyword(s):  
Forest Cover ◽  
Spatial Reasoning ◽  
Remotely Sensed ◽  
Temporal Variations ◽  
Topographic Effects ◽  
Remotely Sensed Data ◽  
Knowledge Based ◽  
Spatial Differences ◽  
Integration Problem ◽  
Map Data

Simple algorithmic methods for integrating remotely sensed data with existing cartographic databases do not provide satisfactory results. One of the main difficulties is in reconciling spatial differences between the two data sources. The differences are due to such diverse factors as temporal variations, spatial errors in the map data, and topographic effects in the remotely sensed data. To investigate the extent of this data-integration problem, a map—image congruency evaluation (MICE) knowledge-based system was developed which performs three distinct operations: (i) pre-processing for uniform representation of both the image and cartographic datasets; (ii) spatial reasoning on the data with the MICE system; (iii) presentation of a congruency evaluation map. Results are presented for a forested area in British Columbia, where Landsat multispectral scanner data are integrated with a provincial forest-cover map.

scholarly journals Forest Cover Changes and Land Use Dynamics in Oluwa Forest Reserve, Southwestern Nigeria

2014 ◽  
Vol 7 (2) ◽  
pp. 25-44 ◽  
Author(s):  
Oluwagbenga O. I. Orimoogunje
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Resource Use ◽  
Forest Cover ◽  
Remotely Sensed ◽  
Remotely Sensed Data ◽  
Southwestern Nigeria ◽  
Forest Reserve ◽  
Ground Truth Data ◽  
Original Species

Abstract This study examined the extent of resource use and the level of degradation consequent upon land use. Three distinctive trends were observed in terms of forest and land cover dynamics. These are forest degradation, deforestation and regeneration. The paper integrated both, topographical map of 1969 and satellite imageries from Landsat MSS 1972, and Landsat TM 1991 and 2000 with ground truthing and socio-economic surveys to assess changes in forest resource use and land cover in South-western Nigeria. The satellite images were analysed using ILWIS software version 3.4. Based on ground truth data and remotely sensed data, the study area was classified into five categories using the supervised maximum likelihood classification technique. The accuracy assessment was carried out on the remotely sensed data. A total of 30 points for each dataset were selected for this operation and the overall accuracy of 90%, 86.7% and 85% respectively was obtained from the three image datasets. Results showed three dominant ecological communities in Oluwa Forest Reserve while two effects of changes on species were identified. The first was the replacement of what could be considered as the original species by other species tolerant to the ‘new’ ecosystem. The other was the reduction in the range of the original species that could be found. This was an indication that the area had been fragmented comparing to its original status. Results suggest that resource utilization and land cover change dynamically over time. The study also revealed that the creation of forest reserve to restrict local access and resource use would have been an effective tool for regulating encroachment and logging activities if there was an effective enforcement of regulation. It is therefore obvious that the main aim of environmental management should be the protection of the natural living space of humankind and integration of environmental scarcity in making decision on all economic issues and activities.

scholarly journals Multi Temporal Remotely Sensed Image Modelling For Deforestation Monitoring

2019 ◽  
Vol 3 (1) ◽  
pp. 43
Author(s):  
Dian Nuraini Melati
Keyword(s):  
Forest Cover ◽  
Tropical Rainforest ◽  
Critical Issue ◽  
Remotely Sensed ◽  
Kappa Index ◽  
Remotely Sensed Data ◽  
Landsat Images ◽  
Multi Temporal ◽  
Remotely Sensed Image ◽  
Image Modelling

Tropical rainforest in Indonesia faces critical issue related to deforestation. Human activities which convert forest cover into non-forest cover has been a major issue. In order to sustain the forest resources, monitoring on deforestation and forest cover prediction is necessary to be done. Remotely sensed data, Landsat images, with acquisition in 1996, 2000, and 2005 are used in this study. In this study area, forest cover decreased around 6 % in the period of 1996 - 2005. For the purpose of forest cover modelling, three model (i.e. Stochastic Markov Model, Cellullar Automata Markov (CA_Markov) Model, dan GEOMOD) were tested. Based upon the Kappa index, GEOMOD performed better with the highest Kappa index. Therefore, GEOMOD is recommended to forecast forest cover.

Groundwater recharge estimation in karst aquifers of southern Apennines (Italy) by integration of remotely sensed data

2019 ◽  
Vol 47 ◽  
pp. 97-101
Author(s):  
Giovanni Ruggieri ◽  
Vincenzo Allocca ◽  
Flavio Borfecchia ◽  
Pantaleone De Vita
Keyword(s):  
Groundwater Recharge ◽  
Remotely Sensed ◽  
Karst Aquifers ◽  
Southern Apennines ◽  
Remotely Sensed Data ◽  
Recharge Estimation
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