Weed flora of historical sites in Şanlıurfa province

This study was conducted to identify the weed flora of historical sites Şanlıurfa province having rich historical background. Surveys were conducted in 19 historical sites (either protected or restored) situated in various districts of the province. Significant historical sites, i.e., Balıklıgöl, Şanlıurfa Castle, Harran Houses, the Old Harran University, Selahaddin Eyyubi Mosque, and the Roman Bath were surveyed. Weed species prevailing in the sites were photographed and identified using Flora of Turkey and East Aegean Islands. The species, EPPO codes, and life forms were recorded. Principal Component Analysis (PCA) was used to analyze the distribution of weed species based on surveyed sites. A total of 45 weed species belonging to 17 families were identified during the study. The families with the highest number of species (60% of the total) were Asteraceae and Poaceae. Less frequently observed families included Bryaceae and Nitrariaceae. The study found that 75% of the species were annual, 20% were perennial, and 5% were biennial. According to the Raunkiær classification, Terofits and Hemikriptofits were the most dominant life forms. Parietaria judaica L. was the most frequently observed species (47.37%) and was concentrated in humid, shaded areas. Sinapis alba L. (42.11%) was commonly found in open and sunlit regions. Less frequently observed species included Fumaria officinalis L. and Setaria verticillate (L.) P. Beauv. Weeds were found to root in cracks or pores in the stones of the structures, causing the stones to disintegrate and reducing the structural integrity of the buildings. Perennial species were noted for their ability to accelerate the degradation of historical structures through their deep root systems. The study emphasizes the necessity of regular maintenance and the controlled removal of weed species from historical structures to protect them. It also highlights that while weeds can sometimes provide ecological benefits, their impact on the structural and aesthetic integrity of historical buildings must be managed. The research underlines the importance of ecological management and sustainable maintenance strategies in the preservation of historical sites.