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Einige rindenbewohnende Flechten sind im Laufe der vergangenen hundert Jahre deutlich häufiger geworden und haben ihr Areal ausgedehnt. Bekannt für diese auf anthropogene Standortveränderungen zurückgehende Förderung sind z.B. Lecanora conizaeoides, Scoliciosporum chlorococcum und Parmeliopsis ambigua. Im vorliegenden Beitrag werden weitere Beispiele diskutiert und Hinweise auf eine Förderung von Hypocenomyce caradocensis, Mycoblastus sterilis, Lecanora expallens, Candelariella reflexa, Cetraria chlorophylla, Parmelia flaventior und anderen in Süddeutschland und Umgebung vorgelegt. Die Ursachen der Ausbreitung liegen in edaphischen und biotischen Veränderungen. Acidophytische Flechten sind durch die forstwirtschaftliche Begünstigung von Nadelbäumen und die Ansäuerung der Baumborke infolge von Immissions-Einwirkungen gefördert worden. Mehrere sind durch ihre hohe Resistenz gegenüber SO2 in der Lage, die veränderten Konkurrenzbedingungen nach dem Verschwinden empfindlicher Arten zu nutzen. Das Phänomen, daß ausgeprägt acidophytische Flechten in belasteten Gebieten auf ursprünglich schwach saure oder subneutrale Rinden übergehen, ist bislang noch nicht für die Bioindikation der SO2-Immission herangezogen worden, regional aber von erheblichem Interesse.
Für fast alle Arten, die in Süddeutschland eine Ausdehnung des Areals zeigen, gibt es Hinweise auf ihre Herkunft. Als Anhaltspunkte dienen Funde in naturnahen Vegetationstypen, die topographische Lage der ältesten Funde sowie pflanzengeographische Überlegungen. Ein Teil der anthropogen geförderten Arten hat danach ursprüngliche Standorte in Sandgebieten und an felsigen Abhängen mit indigenen Kiefernvorkommen, andere, so Lecanora conizaeoides, Mycoblastus sterilis, Hypocenomyce sorophora, in Moor-Randwäldern mit Pinus mugo und vergleichbaren Standorten. Alle diskutierten Arten dürften im südlichen Mitteleuropa einheimisch sein.
Hypocenomyce caradocensis und H. sorophora werden erstmals für Süddeutschland nachgewiesen, Candelariella kuusamoensis und Fuscidea viridis für Deutschland.
During SPURT (Spurenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region) we performed measurements of a wide range of trace gases with different lifetimes and sink/source characteristics in the northern hemispheric upper troposphere (UT) and lowermost stratosphere (LMS). A large number of in-situ instruments were deployed on board a Learjet 35A, flying at altitudes up to 13.7 km, at times reaching to nearly 380 K potential temperature. Eight measurement campaigns (consisting of a total of 36 flights), distributed over all seasons and typically covering latitudes between 35° N and 75° N in the European longitude sector (10° W–20° E), were performed. Here we present an overview of the project, describing the instrumentation, the encountered meteorological situations during the campaigns and the data set available from SPURT. Measurements were obtained for N2O, CH4, CO, CO2, CFC12, H2, SF6, NO, NOy, O3 and H2O. We illustrate the strength of this new data set by showing mean distributions of the mixing ratios of selected trace gases, using a potential temperature – equivalent latitude coordinate system. The observations reveal that the LMS is most stratospheric in character during spring, with the highest mixing ratios of O3 and NOy and the lowest mixing ratios of N2O and SF6. The lowest mixing ratios of NOy and O3 are observed during autumn, together with the highest mixing ratios of N2O and SF6 indicating a strong tropospheric influence. For H2O, however, the maximum concentrations in the LMS are found during summer, suggesting unique (temperature- and convection-controlled) conditions for this molecule during transport across the tropopause. The SPURT data set is presently the most accurate and complete data set for many trace species in the LMS, and its main value is the simultaneous measurement of a suite of trace gases having different lifetimes and physical-chemical histories. It is thus very well suited for studies of atmospheric transport, for model validation, and for investigations of seasonal changes in the UT/LMS, as demonstrated in accompanying and elsewhere published studies.
During SPURT (Spurenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region) we performed measurements of a wide range of trace gases with different lifetimes and sink/source characteristics in the northern hemispheric upper troposphere (UT) and lowermost stratosphere (LMS). A large number of in-situ instruments were deployed on board a Learjet 35A, flying at altitudes up to 13.7 km, at times reaching to nearly 380 K potential temperature. Eight measurement campaigns (consisting of a total of 36 flights), distributed over all seasons and typically covering latitudes between 35° N and 75° N in the European longitude sector (10° W–20° E), were performed. Here we present an overview of the project, describing the instrumentation, the encountered meteorological situations during the campaigns and the data set available from SPURT. Measurements were obtained for N2O, CH4, CO, CO2, CFC12, H2, SF6, NO, NOy, O3 and H2O. We illustrate the strength of this new data set by showing mean distributions of the mixing ratios of selected trace gases, using a potential temperature – equivalent latitude coordinate system. The observations reveal that the LMS is most stratospheric in character during spring, with the highest mixing ratios of O3 and NOy and the lowest mixing ratios of N2O and SF6. The lowest mixing ratios of NOy and O3 are observed during autumn, together with the highest mixing ratios of N2O and SF6 indicating a strong tropospheric influence. For H2O, however, the maximum concentrations in the LMS are found during summer, suggesting unique (temperature- and convection-controlled) conditions for this molecule during transport across the tropopause. The SPURT data set is presently the most accurate and complete data set for many trace species in the LMS, and its main value is the simultaneous measurement of a suite of trace gases having different lifetimes and physical-chemical histories. It is thus very well suited for studies of atmospheric transport, for model validation, and for investigations of seasonal changes in the UT/LMS, as demonstrated in accompanying and elsewhere published studies.