Pollination behaviour of Linum aretioides Boiss. (Linaceae) and its relations with air temperature and humidity

Linum aretioides Boiss., a local endemic, is distributed only on 2 mountains (Izmir: Bozdag; Denizli: Babadag) at the western part of Turkey between 1630 and 2300 m altitudes, above the tree line. The studies were conducted on Mount Bozdag above the ski complex between 1750 and 2150 m, and on Mount Babadag between 1630-2300 m both located at subalpine zones. Four 8 x 8 m quadrats on Bozdag and 5 on Babadag were used for the experiments. The development of reproductive structures of plants and frequency of insect visits were observed from early May to late June in 2006 and 2007. Blooming and pollination periods terminated by the last week in May on Babadag and by the second week in June on Bozdag. Temperatures below 10 degrees C before these periods appear to affect the activities of main pollinators, such as bees and butterflies, resulting in a decline in pollination, and eventually in seed formation. In Bozdag, the average relative humidity values at 1000 hours, when the insect activities were the highest, were 65.22 +/- 2.79% in June 2006, 61.6 +/- 4.44% in May 2007, and 59.6 +/- 3.53% in June 2007. The corresponding values on Babadag were 52.8 +/- 3.1%, 59.58 +/- 3.52%, and 53.28 +/- 3.41%, respectively. The most effective species in pollination process were butterflies, in particular Pieris brassicae.