Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Añadir filtros








Intervalo de año
1.
J Environ Biol ; 2010 May; 31(3): 369-373
Artículo en Inglés | IMSEAR | ID: sea-146427

RESUMEN

Fire is an important tool in the management of forest ecosystems. Although both prescribed and wildland fires are common in Turkey, few studies have addressed the influence of such disturbances on soil properties and root biomass dynamics. In this study, soil properties and root biomass responses to prescribed fire were investigated in 25-year-old corsican pine (Pinus nigra Arn.) stands in Kastamonu, Turkey. The stands were established by planting and were subjected to prescribed burning in July, 2003. Soil respiration rates were determined every two months using soda-lime method over a two- year period. Fine (0-2 mm diameter) and small root (2-5 mm diameter) biomass were sampled approximately bimonthly using sequential coring method. Mean daily soil respiration ranged from 0.65 to 2.19 g C m-2 d-1 among all sites. Soil respiration rates were significantly higher in burned sites than in controls. Soil respiration rates were correlated significantly with soil moisture and soil temperature. Fine root biomass was significantly lower in burned sites than in control sites. Mean fine root biomass values were 4940 kg ha-1 for burned and 5450 kg ha-1 for control sites. Soil pH was significantly higher in burned sites than in control sites in 15-35 cm soil depth. Soil organic matter content did not differ significantly between control and burned sites. Our results indicate that, depending on site conditions, fire could be used successfully as a tool in the management of forest stands in the study area.

2.
J Environ Biol ; 2010 Jan; 31(1): 15-19
Artículo en Inglés | IMSEAR | ID: sea-146326

RESUMEN

In this study, soil properties and root biomass responses to prescribed fire were investigated in 25-30 year-old calabrian pine (Pinus brutia Ten.) stands in Edirne, Turkey. The stands were established by planting and were subjected to prescribed burning in July, 2005. Soil respiration rates were determined every two months using the soda-lime method over a two-year period. Fine (>2 mm diameter) and small root (>2-5 mm diameter) biomass were sampled approximately bimonthly using the sequential coring method. Soil respiration rates in burned sites were significantly higher than in control sites during the summer season but there was no significant difference in the other seasons. Soil respiration rates were correlated significantly with soil moisture and soil temperature. Fine and small root biomass were significantly lower in burned sites than in control sites. Mean fine root biomass values were 3204 kg ha-1 for burned and 3772 kg ha-1 for control sites. Annual soil CO2 releases totaled 515 g C m-2 for burned and 418 g C m-2 for control sites. Our results indicate that, depending on site conditions, fire could be used successfully as a tool in the management of calabrian pine stands in the study area.

3.
J Environ Biol ; 2005 Apr; 26(2): 179-85
Artículo en Inglés | IMSEAR | ID: sea-113520

RESUMEN

In this study, some heavy metal concentrations (Pb, Zn, Fe, Cr, Cu), suspended sediment, chemical oxygen demand (COD), biological oxygen demand (BOD), cyanide, phenol, fecal coliform and total coliform water parameters were determined in the streams (Kucuk Melen, Asarsuyu, Ugursuyu, Buyuk Melen and Aksu) of Buyuk Melen Watershed that provides drinking water to Istanbul in Western Black Sea Region of Turkey. Measurements of water quality parameters were done monthly in eleven separate stations (4 in Kucuk Melen Stream, 1 in Asarsuyu Stream, 1 in Ugur Stream, 1 in Aksu Stream and 4 in Buyuk Melen Stream) from August 2001 to August 2002. The seasonal changes in water quality parameters were evaluated statistically. The results, the parameters, COD, BOD, Pb, Zn, Fe, Cr, Cu, cyanide, fecal coliform, total coliform and suspended sediment showed significant differences among seasons and streams (ANOVA; P <0.05). According to Turkish Standarts (TS) 266, European Union (EU) and World Health Organization (WHO) criteria, the maximum values of each parameter in streams within the Buyuk Melen watershed are recorded and evaluated in this study.


Asunto(s)
Recuento de Colonia Microbiana , Cianuros/análisis , Enterobacteriaceae/aislamiento & purificación , Monitoreo del Ambiente , Metales Pesados/análisis , Oxígeno/análisis , Fenol/análisis , Ríos/química , Estaciones del Año , Turquía , Microbiología del Agua , Contaminantes Químicos del Agua/análisis
4.
J Environ Biol ; 2004 Apr; 25(2): 125-34
Artículo en Inglés | IMSEAR | ID: sea-113284

RESUMEN

Deltas, as macro and micro biological systems at high productive levels, are the natural reserve areas of the world. Those in Turkey present the international importance landscapes as to the various ecosystem characteristics and land use patterns. Nevertheless, these areas are currently facing many problems such as biodiversity loss and environmental degradation owing to coastal settlements and pollution factors. This paper describes the factors responsible for the main features and degradation types of the Deltaic landscapes and their impact for future land use. It also deals with : an overview of the Kizilirmak Delta, one of the most important Deltas along the central part of Black Sea Region (Turkey); presents major ecosystem of it; identifies land use pattern and discusses the threats by environmental and human induced disturbances. The most considering feature of this Delta is to show the largest and most significant wetland area of Turkey which has been able to protect its natural beauties on the Black Sea Coasts. A Delta plain of 56000 hectares extends through the area at the north of the Samsun-Sinop highway. The ecological system of the Delta is extremely rich in terms of its biological variety as well as its fauna (especially number of bird species). But, the Delta including terrestrial areas close to the water resources and the vegetation between aquatic and terrestrial systems, has been constantly modified by human activities. Consequently, some considerations for environmental conservation and sustainable management were put forward for the future generations.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Planificación Ambiental , Humanos , Plantas , Ríos , Turquía , Abastecimiento de Agua
5.
J Environ Biol ; 2003 Oct; 24(4): 415-22
Artículo en Inglés | IMSEAR | ID: sea-113576

RESUMEN

The Değirmendere and Galyan (Değirmendere tributary) Rivers that discharge their water into the Black Sea are important watersheds in the northeastern part of Turkey. Water quality parameters were sampled from 1997 through 2001 for each year at five sites (three for Galyan, two for Degirmendere) along 29 and 42 km gradients, respectively covering all seasons. Surface water was collected from the sites and analyzed for temperature, total alkaline (MAAL), total dissolved solids (TDS), dissolved oxygen (DO), pH, conductivity (EC), nitrate (NO3), nitrite (NO2), total hardness (TH), phenolphthalein alkalinities (PAL) and organic matter (PV). Seasonal changes of water quality were analyzed statistically for both Rivers and evaluated according to the TS 266, EU and WHO standards. The analysis of variance results showed that Ca, Mg, MAL, NO3, pH, TDS and TH parameters of the Değirmendere River and Ca, DO, EC, MAL, NO3, pH and TH parameters of the Galyan River showed seasonal differences (p<0.05). The maximum values of the water pollution parameters for the two Rivers were below the threshold values throughout the study period. When both Rivers were compared, the mean values of the pollution parameters of the Degirmendere River were higher than those of the Galyan River and very close the limits. The results indicate that both Rivers can be used for the production of potable water during all seasons but only with an advanced treatment in the Değirmendere and a moderate treatment in the Galyan River, and for indirect and non-contact recreational activities.


Asunto(s)
Análisis de Varianza , Conductividad Eléctrica , Monitoreo del Ambiente/estadística & datos numéricos , Concentración de Iones de Hidrógeno , Oxígeno/análisis , Ríos/química , Estaciones del Año , Temperatura , Turquía , Contaminación del Agua/análisis
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA