Finding spatial regularity in mosaic landscapes: two methods integrated

Two methods were employed to find spatial regularity in a complicated mount ain landscape of Beijing, China on the basis of functional and structural a ffinities. The first approach applied Affinity Analysis based on species co mposition to landscape. The mosaic diversity of the landscape was 3.5298 >3 , which means the study landscape is complex and controlled by multiple env ironmental gradients. These landscape types were divided into 3 parts accor ding to the mean affinity values of 0.2143 and 0.7857 (0.5 +/-1 SD). Modal sites are the central types of the landscape, which include a zonal broad-l eaved forest of the region and a conifer plantation replacing the former. O utliers are found in the highest altitude and the lowest, both have few spe cies in common with the above two modal types. The remaining landscape type s are intermediate sites, which are transitional between modals and outlier s, broadly distributed throughout mountain environments. Neighbor types hav e more species in common than those more widely separated, which probably d istributed adjacently in space or in similar quality habitat. The other met hod employed is the new TWINSPAN analysis by substituting spatial neighbori ng data of landscape types for species composition data. It clearly divided the landscape types into three groups, i.e., subalpine, middle and low mou ntain groups, which were correlated with altitude, as well as influenced by human disturbance. The new TWINSPAN classification method is more reliable in finding spatial gradient of patchy landscapes than affinity analysis; h owever, affinity analysis is useful in finding species diversity pattern an d the importance of landscape types in a region. Integrating advantages of the two methods could supply complete and reliable information on how lands cape types are distributed in space, which environmental gradient dominates the spatial distribution of the landscape types, as well as where importan t and unusual types are located.