Effect of changing land use patterns on the distribution of coho salmon (Oncorhynchus kisutch) in the Puget Sound region

2008 ◽  
Vol 65 (10) ◽  
pp. 2138-2148 ◽  
Author(s):  
Robert E. Bilby ◽  
Lauren A. Mollot

Population increase in the Pacific Northwest of North America over the last century has led to the removal of forests for various purposes. Evidence of salmon response to these alterations in land use is rare owing to a scarcity of fish population data and a high degree of interannual variation in abundance. We examined the relationship between the spatial distribution of spawning coho salmon ( Oncorhynchus kisutch ) and changes in land use from 1984 through 2001 at 84 sites in four rivers draining into northern Puget Sound. Changes in land use over this period were determined from LandSat imagery, county zoning designations, and aerial photographs. Substantial reduction in forest cover occurred in many of the index watersheds during this time. The proportion of salmon using sites subjected to increased urban land use over the study period declined about 75%. Increases were observed at forested sites and those with increased rural residential use. Maintaining salmon populations in rapidly developing areas may require the identification and protection of sites that support large salmon populations and steering development to areas supporting few fish.

2020 ◽  
Vol 19 (1) ◽  
pp. 150-158
Author(s):  
A. O. TOBORE ◽  
G. OYERINDE ◽  
B. A. SENJOBI ◽  
T. O. OGUNDIYI

Landsat satellite imagery plays a crucial role in providing information on land use/cover modifications on local, regional, and global scales, especially where aerial photographs are missing. Monitoring land-use changes from past to present tends to be time-consuming especially when dealing with ground-truth information. Determining the past and current land-use change on Earth's surface using Landsat imagery tends to be effective and efficient when high-resolution imagery is unavailable. This study employed the use of Landsat satellite imagery to assess the past and present land use/cover using supervised classification and Normalized Difference Vegetation Index (NDVI). The result of the supervised classification land use/cover showed that forest cover and woodland undergo rapid loss, while farmland, wetland, built-up, and waterbodies tend to experience gradual loss. The NDVI demonstrated that farmland and forest cover was the most affected land use/cover. Hence, land use/cover of the study area is affected by human activities, such as intensive farming, population size, and deforestation.  


Forest cover in Bengkulu is reduced. Data from WARSI shows, 1990 forest cover areas in the province are approximately 1,009,209 hectares or 50.4 % of the land area reaching 1,979,515 hectares. But now, it is only 685,762 hectares of the area of his blood. That is, the period of 25 years, there is a forest cover decline of 323,447 hectares. Forest and land cover changes are the largest contributor to greenhouse gas emissions. The purpose of this article is to see land cover changes based on carbon stock in the years 2009 and 2018. Model of land cover change based on carbon stock year 2028 and 2038. The method of this research uses the calculation of the Stock Difference Approach with spatial analysis of national land closure of Landsat imagery 2009-2018 and biomass data for forest inventory results Geographic Information System (GIS). The results of this research were the reduced forest area and the change in land use changed from 2009 and 2018. So carbon stock is also increasingly reduced.


Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 867 ◽  
Author(s):  
Justyna Jaworek-Jakubska ◽  
Maciej Filipiak ◽  
Anna Napierała-Filipiak

Though on a global scale, for ecological reasons, increased forest cover is universally regarded as positive, on a local scale, the reforestation of arable land may pose threats to cultural landscapes by removing characteristic landscape features. Particularly vulnerable are marginal rural areas, e.g., mountain regions, where most traditional land use systems have survived and which are subject to the most spectacular land use change. The purpose of this article is to draw attention to the issue of the management of forest cover in historical cultural landscapes in mountain territories in Poland within the context of widespread land use change in Eastern Europe. Land cover data were obtained from historical and contemporary aerial photographs, as well as topographic maps from five time points between 1824 and 2016. The study was conducted by means of spatio-temporal forest cover trajectory analysis (LCTA), transition and time–depth analysis, and land cover change calculations that were made by means of ArcGIS. Our research indicates that the rate of change has risen considerably in the last two decades, and the current share of forest cover is much bigger than that reflected in the official data. Eight principal forest cover trajectory types were identified. The biggest area is occupied by woodland of long-term stability. Another large group is constituted by forests created on the basis of arable land and grassland as a result of simple conversion at one point in time, mainly in the years 1824–1886 and 1939–1994. At the same time, a sizeable group is made up by areas that have been subject to unplanned cyclical or dynamic changes during various periods. A very important group is comprised new forests that were created in 1994–2016, predominantly as a result of natural succession, that are often not included in official land classifications. The constant expansion of woodlands has led to a shrinking of historical former coppice woodlands. This indicates that the current landscape management mechanisms in Poland are inadequate for protecting the cultural landscape. The barriers include the lack of intersectoral cooperation and the overlooking of the historical context of landscapes. The present situation calls not only for verification of the existing forest policy but also for increasing the role and engagement of local communities, as well as making comprehensive local development plans, all of which may be helped by the findings of our study and of similar research.


2014 ◽  
Vol 42 (1) ◽  
pp. 12-19 ◽  
Author(s):  
CHRISTOPHER M. HAMILTON ◽  
WAYNE E. THOGMARTIN ◽  
VOLKER C. RADELOFF ◽  
ANDREW J. PLANTINGA ◽  
PATRICIA J. HEGLUND ◽  
...  

SUMMARYLand-use change around protected areas limits their ability to conserve biodiversity by altering ecological processes such as natural hydrologic and disturbance regimes, facilitating species invasions, and interfering with dispersal of organisms. This paper informs USA National Wildlife Refuge System conservation planning by predicting future land-use change on lands within 25 km distance of 461 refuges in the USA using an econometric model. The model contained two differing policy scenarios, namely a ‘business-as-usual’ scenario and a ‘pro-agriculture’ scenario. Regardless of scenario, by 2051, forest cover and urban land use were predicted to increase around refuges, while the extent of range and pasture was predicted to decrease; cropland use decreased under the business-as-usual scenario, but increased under the pro-agriculture scenario. Increasing agricultural land value under the pro-agriculture scenario slowed an expected increase in forest around refuges, and doubled the rate of range and pasture loss. Intensity of land-use change on lands surrounding refuges differed by regions. Regional differences among scenarios revealed that an understanding of regional and local land-use dynamics and management options was an essential requirement to effectively manage these conserved lands. Such knowledge is particularly important given the predicted need to adapt to a changing global climate.


1974 ◽  
Vol 31 (6) ◽  
pp. 1158-1160 ◽  
Author(s):  
Stephen B. Mathews ◽  
Raymond Buckley

The natural mortality rate during a 3.5-mo period of the last year of life of coho salmon (Oncorhynchus kisutch) resident in Puget Sound was estimated to be 48% of the population at the beginning of this period. This estimate was based on recaptures of 29 fish out of 169, averaging 32 cm in fork length, tagged in January and early February, and 20 out of 61 averaging 41 cm tagged in May and early June, 1970.


2007 ◽  
Vol 6 (2) ◽  
pp. 75-88
Author(s):  
Kotresha K. ◽  
Indra Jit Singh

The forests are the source for many essential requirements such as fuel wood, timber, raw materials for paper and above all, it helps us to maintain the CO2 /O2 balance in nature. Sustainable forest management requires reliable information. The aerial photographs and GIS data information can generate various scenarios for forest management plans at local, national and global scales. IKONOS is the world first one-meter resolution commercial imaging satellite. The interpretation of aerial photograph and satellite data are of great benefit for neighboring and regional land use, forest mapping, to find change detection and are effective for large are inventories, forest planning etc. In the present study, an attempt has been made to classify the FRI forest in to 11-forest cover and land use classes. The major chunk of forest consists of Pine forest, which occupy 94.04 ha and 143.20 ha of the total forest area during 1973 and 2001, respectively. It is followed by mixed forest with 53.31 ha (1973) and 5.50 ha (2001), and Teak with 17.68 ha (1973) and 8.49 ha (2001). The Sal forest showed an increase in forest cover from 4.83 ha (1973) to 5.39 ha (2001). Similarly Eucalyptus forest showed a forest cover of 1.84 ha in 2001, which was not seen in the year 1973. The constructions also showed an increase from 3.14 ha in 1973 to 24.68 ha in 2001 and in case of nursery and miscellaneous (scrub), there has been increasing in total forest cover. The IKONOS image of 2001 surprisingly showed no change in Champa forest cover. Decrease in forest cover of Teak, Sal and Mixed forest must have been due to felling of trees for logging purposes and their forest cover might have been replaced by scrub vegetation (miscellaneous) , construction, Eucalyptus plantation and nursery. The results of the present project showed changes in terms of area coverage by the forest types, which helps us to assess future prospects of the forestland use pattern.


2016 ◽  
Vol 4 (3) ◽  
pp. 1 ◽  
Author(s):  
Lirih Wigaty ◽  
Samsul Bakri ◽  
Trio Santoso ◽  
Dyah Wulan S. R. Wardani

Ecological disruption as a result of changes in the area of forest cover to other land uses can affect the microclimate and impact toward malaria morbidity.   Malaria is an infectious disease caused by protozoa a genus of Plasmodium that transmitted by female Anopheles sp. mosquito vectors.  The environmental factors that play a role in the risk to transmission of malaria related to vector breeding places.   The purpose of this research is establish the impact of land use changes toward malaria morbidity. This study was conducted from March to September 2015.   Dynamics of land use changes in regency/city be identified through interpretation of landsat imagery in 2002, 2009, and 2014 with supervised classification and resulted in percentage of land use, the influence of impact toward malaria morbidity processed using multiple linear regression models.  Parameter optimization using statistic software.   The result showed that the impact of positive variable that significant toward malaria morbidity are mangrove forest and total population, while impact of negative variable that significant are extensive swamp and health personnel.   Variable which not impact that significant toward malaria morbidity are forests, community forests, undeveloped land, dry land, other land uses, population density, precipitation, unhealthyhousing, urban, and physiographic. Keywords : land use, malaria morbidity


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