Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 63. (Budapest 1971)
Fekete, G. ; Szujkó-Lacza, J.: A survey of the plant life-form systems and the respective research approaches III. Rankiaer's life-form conception. The application of life-forms in the characterization of phytoclimate and in vegetation analysis
b. Life-form and aspects Within the several layers of the associations a further —temporal —differentiation can be demonstrated, usually termed as aspect change. The arrangement in one site of the species of an association is in many cases the consequence of a differentiated life-form, in contrast with light adaptation determining the stratification and structure of the association. We deem it interesting to compare the concepts of aspect as given in the various contextual exposition of the leading authors. BRAUN—BLANQUET (I.e.) formulates from his climate-rhythmical standpoint: "Physiognomisch zeichnen sich die Jahresperioden vor allem aus durch die Aufeinenderfolge verschiedener Blühe- und Belaubungswellen, die den einzelnen Etappen oder Aspekten einen durchaus abweichenden Anstrich verleihen. Soziologisch wichtiger erscheint jedoch der Wechsel, der sich im Laufe des Jahres im Artenbestand auswirkt. ... Da die Raumeinnahme einer Art im Verlauf des Jahres Schwankungen unterworfen sein kann, steht derselbe Raum zeitlich unter Umständen zwei oder auch mehreren Arten, die verschiedenen Lebensformengruppen angehören, zur Verfügung." SCHARFETTER (1922) pointed out the occasional deviations of vegetational and climatic rhythms by a number of species having come into being in regions with a different climate of their present locality, so that the periods of leafing, blossoming, fructification, and quiescence do not concur with the climatic rhythm of the region the respective species now inhabit. (Among others, he puts forth the example of Colchicum autumnale, in his contention a plant of Mediterranean origin. Using precipitation and temperature maps, he shows, for the Mediterranean areas, the summer period of quiescence —absence of rainfall —and the spring and autumnal vegetation periods. This rhythm can be discovered in the developmental cycles of plants of a similar origin even if they live now in the Central European continental climate.) On the basis of phenological observations, PRISZTER (ex verb.) substantiates the same by his phenological calendar giving the supraterranean appearance of the Geophytes. According to RUBEL (1930), the aspects exist owing to these vegetational rhythms, differing from the climatic rhythms and explainable by the diverse origin of the species. Soó (1945), too, approaches from the standpoint of space utilization the problem of aspect. According to JAROSENKO (1961): "Aspect is the physiognomy of the association at the given time . . . The seasonal change of aspects is closely connected with the alterations of structure and the functioning of the association. If the seasonal change of structure manifests itself in physiognomy, then the seasonal alteration of vital functions becomes periodocity. Yet in understanding seasonal periodicity one cannot regard merely external manifestations (leafing, blossoming, fructification), but also the hidden (subterranan) processes (e.g. root development) should also be taken into account." Our own view concerning aspects stands nearest to JAROSENKO'S (I.e.) tenets. According to our formulation, the presence of aspects, in the identical layer of a vegetational unit but each at different seasons, is nothing else than the population sets of species utilizing the identical space level by diverse life cycles. In the framework of one set, the given specific populations stand, within certain limits, near one another with respect to light requirement (e.g. in a forest). If one thinks now of the Cryptophytes and the appearance of their hidden phasis at different times, a species with a Cryptophyton life-form will show a low interspecific association with e.g. a species of the Hemicryptophyton life-form, in the common appearance of their supraterra-
