Number of natural monuments and monumental trees in Poland based on the General Directorate for Environmental Protection inventory from the years 2014-2015

In 2014−2015, the General Directorate for Environmental Protection carried out an inventory of natural monuments in Poland. The data collected during this process was used to update and expand the generally available Central Register of Nature Protection Forms (CRFOP). Based on these material, the assignment of nature monuments to particular categories was verified and their number in individual categories was calculated. In addition, the species composition of trees being single monuments of nature and growing in monumental groups and alleys was determined. The total number of monumental trees in Poland was also calculated, with the division into species. For the 50 of most popular individual monument tree species, the minimum, maximum and average circumferences of their trunks were determined. A group of the most impressive monument trees with trunk circumferences exceeding 600 cm was also selected. According to the calculations, there are 36,570 natural monuments in Poland, of which 94% are trees and shrubs (individual trees – 28,304, groups of trees – 551 and alleys – 525). Individual trees natural monuments represent at least 161 species, trees growing in groups of at least 123 species, and trees growing in alleys at least 53 species. The total number of monumental trees growing as single specimens, in groups and alleys is at least 123,784 pieces, with at least 46,636 trees growing in groups, and at least 48,844 trees in alleys. In total, the monumental trees of Poland (growing singly, in groups and alleys) belong to at least 178 species, including 51 gymnosperms and 127 angiosperms. The CRFOP data also shows that there are 1641 trees that have reached or exceeded the trunk circumference of 600 cm, among which there are 77 specimens with a circumference equal to or greater than 800 cm. However these data do not coincide with information available in current literature and they need to be verified. The obtained calculations are the most up−to−date report on the numerical status of trees – natural monuments based on data confirmed by field inventory, and not only on the registers of nature monuments containing often unverified or non−actual data