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Comparison of the impacts of climate change and anthropogenic disturbances on the El Arish coast and seaweed vegetation after ten years in 2010, North Sinai, Egypt

El Shoubaky G. A.

Oceanologia

2013

No. 55 (3)

663--685

Human activities on coasts and climate changes during the past ten years have given rise to considerable shoreline changes along the El Arish coast (the northern coast of the Sinai Peninsula). In the El Arish Power Plant, sediment accretion has reached the tip of the breakwater of the cooling water intake basin, necessitating extensive dredging inside the basin. To the east of El Arish Harbour, the shoreline has been in continuous retreat. The differences between the year 2000 and 2010 in the shoreline along the El Arish coast were determined by analysing satellite images from NOAA-AVHRR images. The analyses revealed erosion and accretion patterns along the coast. The physical parameters showed that the minimum water temperature of 18°C was recorded at site I in winter and that the maximum was 40°C at site II in summer. The latter temperature can be attributed to the effluent discharge of cooling water from the El Arish power plant. Spatial and temporal patterns in the distribution and abundance of macroalgae were measured at four sites (I, II, III and IV) along the El Arish coast. The percentage cover of the successional macroalgae exhibited environmental fluctuations. After ten years, the phytocommunity showed that red and green algae were dominant at the study sites. Significant differences between past and current flora were observed. 39 taxa recorded in 2000 were absent in 2010, while 9 taxa not previously reported were present in 2010. These changes are discussed in the context of possible global warming effects. PERMANOVA showed significant changes (p < 0.001) between sites, seasons, species abundance and macroalgal groups along the El Arish coast in 2000 and 2010. The similarity matrix showed a significant difference between the flora in 2010 and that recorded in 2000, indicating poor similarity and changes in species composition among the seasons at the different sites. Most of the algae belonged to the filamentous, coarsely branched and sheet functional form groups.

Avian responses to undergrowth removal in a suburban wood

Orłowski G., Martini K., Martini M.

Polish Journal of Ecology

2008

Vol. 56, nr 3

487-495

The breeding (in 1991-1996) and wintering (1991/1992-1993/1994) avian community were surveyed in a suburban wood (29.27 ha) in Wrocław city (SW Poland). The 1992 breeding season began together with a drastic clearance of the compact undergrowth with the use of heavy machinery. A slump of abundance of the species nesting on the ground and small shrubs ([less than or equal to]1.5 m) followed, coupled with some modifications to their breeding behaviour, such as clustering of several singing males on the remaining bushes (Blackcap Sylvia atricapilla L.) and nesting in the piles of cut branches (Blackbird Turdus merula L.). As a result of the removal of 52% of the whole undergrowth the density of species nesting on the ground and small shrubs in 1992 was by 26% lower than in 1991 (decrease from 61.8 to 46.3 pairs 10 ha[^-1]). After 1993 a spontaneous regeneration of the bushy vegetation took place, with the ground and shrub-nesting species. density recovering to 49.4 pairs 10 ha[^-1] in 1996. After 1991 the park was colonized by 9 new hole-nester species, which was accompanied by the increase of density of this group (from 21.9 in 1991 to 37.9 pairs 10 ha[^-1] in 1996). Throughout the entire study period a slight rise of density of birds nesting in tree canopies was visible (21.3 pairs 10 ha[^-1] in 1991 and 33.8 pairs 10 ha[^-1] in 1996). A year after the shrub clearance the wintering bird abundance was significantly lower (half of the previous numbers), with plant-eaters and insectivores hardest hit, especially Great Tit Parus major L. (average number of inidividuals per one count amounted to 59.2 in 1991/1992 and 21.9 in 1992/1993) and Blue Tit Parus caeruleus L. (respectively 37.0 and 16.0 ind.). An adequate timetable of vegetation clearance must be set up in the course of any decision-making process regarding green areas management to ensure the environmental issues are addressed properly.