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1.
The critical load concept is now accepted throughout Europe as a means of estimating the sensitivity of key components of aquatic and terrestrial ecosystems to atmospheric inputs of sulphur (S) and nitrogen (N). Current UK freshwater maps, based on steady-state water chemistry, are derived using a critical acid neutralising capacity (ANCLIM) value of zero eql–1, which is based on the probability of occurrence of salmonid fish in lakes. In practice most acidification damage to salmonid fish occurs in nursery streams at the emergence and first feeding stages. In general a clear relationship exists between salmon (Salmo salar L.) and trout (S. trutta L.) densities in Scottish streams and ANC values. However, differences between sites depend on which ANC value is used (eg maximum, minimum or mean). By contrast, when the exceedance of critical loads is compared with salmonid densities the relationship is less clear because many exceeded sites have good salmonid densities. Many of these latter sites are found in north-west Scotland where sea-salt inputs are high and ANC is usually greater than zero eql–1, although diatom-based studies indicated slight acidification of these waters, with a point of change in diatom flora close to ANC=20 eql–1. These false exceedances are probably due to preferential adsorption of acidic SO4 deposition which results in an overestimate of exceedance values. All sites with a mean ANC 0 are fishless but some sites with negative minimum ANC values had normal salmonid densities. Consequently a mean ANCLIM value of zero in the critical load equations for UK freshwaters appears to be too low to protect salmonid stocks. Values between 20–50 eql–1 represent a more realistic range if prevention of long term damage to salmonid stocks is to be achieved.  相似文献   

2.
Cost-benefit analysis is one of the fundamental tools for the development of economic instruments for pollution control. The costs of various abatement measures are reasonably well characterised. However, assessment of the economic costs of pollutant impacts is less well developed. This paper reports on two studies carried out for DGXII of the European Commission, the ExternE-Project and the Green Accounting Research Project. Both studies have been performed by international, multi-disciplinary research teams.Analysis of the effects of emissions of PM10, SO2, NOx and VOCs (as ozone precursors) has included assessment of human health, materials, crops and other terrestrial ecosystems, and freshwater fisheries. The analysis follows the impact pathway approach, linking dose-response functions, valuation data and other models. It differs significantly to earlier top-down approaches that made only very limited use of the wealth of scientific data available. Most success has been achieved in analysis of impacts on human health, building materials and crops. Significant uncertainties exist for these receptors, though these have been identified and are now being addressed. Assessment of impacts on other receptors, perhaps most notably forests, is more limited. The methodology is particularly applicable for analysis of impacts on receptors for which the critical loads approach is not appropriate.  相似文献   

3.
The degree to which floating aquatic plants concentrate Se in tissues was determined for four species grown in solutions containing various levels of Se. Results of this greenhouse study showed that all four plant species, Azolla caroliniana, Eichhornia crassipes, Salvinia rotundi folia, and Lemna minor absorbed Se quickly upon exposure to Se in water as concentrated as 2.5 g Se mL–1, and attained maximum tissue concentrations within 1 to 2 weeks. Azolla absorbed Se to the highest tissue concentration (about 1000 g Se g–1 dry matter) from the 2.5 g Se mL–1 solution, followed by Salvinia (700 g Se g–1), Lemna (500 g Se g–1),and Eichhornia (300 g Se g–1). Plant growth appeared unaffected by solution Se concentrations lower than about 1.25 g mL–1. These results indicate potential for rapid Se movement from water into aquatic food chains, and for use of aquatic plants for Se removal in wastewater treatment systems.  相似文献   

4.
Sulphate concentrations and 34S ratios were monitored in bulk precipitation, spruce throughfall, and soil water (depth of 30 and 90 cm) at ervená jáma (CER) and Naetín (NAC), two severely polluted sites in the Czech Republic, between December 1992 and September 1994. Throughfall [SO4 2–], up to 80 mg L–1 in winter and as low as 7 mg L–1 in summer, was higher than [SO4 2–] in bulk precipitation (annual average 6 mg L–1). There was a distinct seasonaity in S isotope abundances, with lower 34SBULK in summer (+4 per mil CER, + 6 per mil NAC) and lower 34STF in winter (+3 per mil CER, +4 per mil NAC). Wintertime 34SBULK was around +8 per mil at CER and +10 per mil at NAC, summertime 34STF was close to +7 per mil at both sites. For only a 1- month period in spring, bulk precipitation S became isotopically lighter than throughfall S. Bulk precipitation data from CER were in good agreement with those from the nearby monitoring station Lesná (LES), typically differing by less than 10 mg L–1 and 2 per mil in [SO4 2–] and 34S, respectively. Suction lysimeters (soil depth of 30 and 90 cm) yielded higher sulphate concentrations and lower 34S ratios compared to both bulk and throughfall precipitation. Little seasonality was observed in [SO4 2–] at 30 cm (around 40 mg L–1); at 90 cm [SO4 2–] was higher in winter (70 mg L–1) than in summer (45 mg L–1). 34S at 90 cm was <+5 per=" mil=" in=" 1993=" and=" up=" to=" +7.5=" in=" 1994,=" lower=" in=" the=" first=" year=" and=" higher=" in=" the=" second=" year=" compared=" to=" the=" depth=" of=" 30=" cm.=" sulphur=" fluxes=" at=" cer=" and=" nac=" are=" characterized=" by=" distinct=" isotope=" compositions=" and=" can=" therefore=" be=" used=" to=" trace=" s=" pathways=" and=" transformations=" in=" the=" forest=">  相似文献   

5.
Precipitation chemistry at sinhagad-a hill station in India   总被引：1，自引：0，他引：1  
The chemistry of precipitation in remote sites such as mountain tops is of interest in the study of atmospheric pollution and acid rain. The chemical composition measured at mountain site which is away from industrial and urban areas is useful as a reference level and it allows to determine the extent of anthropogenic contamination. Hence, rain water samples were collected at Sinhagad (18°21N, 73°45E, 1450 m asl during the monsoon season (June-September) of 1992 and were analysed for major ions. The precipitation samples collected at Sinhagad were alkaline in nature and pH values ranged between 5.9 to 6.76. The ionic composition was dominated by soil dust The concentration of Ca2+ was highest among all the ions. The concentrations of excess SO3 2– and NO4 – were small (23.8 and 15.2 eq l–1 respectively) compared to the values of polluted regions in India. The correlation coefficient between the ions and pH values was calculated and it was found to be maximum in case of Ca2+. Precipitation samples collected at Sinhagad were alkaline owing to higher concentration of Ca2+ and lower levels of acidic pollutants (SO4 2– and NO3 –).  相似文献   

6.
Computer assessments of the atmospheric chemistry and air quality of the past, present, and future rely in part on inventories of emissions constructed on appropriate spatial and temporal scales and with appropriate chemical species. Accurate inventories are also of substantial utility to field measurement scientists and the regulatory and policy communities. The production of global emissions inventories is the task of the Global Emissions Inventory Activity (GEIA) of the International Global Atmospheric Chemistry Project (IGAC). This paper presents a summary of recent emissions inventories from GEIA and other programs for reference year 1985, with special attention directed to emissions of the acid-related compounds CO2 (6.2 Pg C yr–1 anthropogenic), SOx (65 Tg S yr–1 anthropogenic and 15 Tg S yr–1 natural), NOx (21 Tg N yr–1 anthropogenic and 15–20 Tg N yr–1 natural), HCl (55 Tg Cl yr–1 total), and NH3 (45 Tg N yr–1 total). The global acid-equivalent flux of about 4.2 Teq H+yr–1 is about equally attributable to SOx and NOx emissions. For some of the acid-related species, historic inventories are available for a century or more; all show dramatic emissions increases over that period. IPCC scenario IS92a is used here as the basis for constructing global acid-related emissions estimates for selected years to 2100; among the results are that acid equivalent emissions are expected to more than double in the coming century.  相似文献   

7.
The SO2 emissions from the Kola Peninsula in Arctic Russia (totalling around 600 Gg(SO2) yr–1 at the beginning of the 1990s) produce an atmospheric SO2 concentration gradient to the northernmost Europe. This gradient covers the range from >50 g m–3 in the vicinity of the sources to 1 g m–3 in Finnish Lapland. In the present study, the measured sulphur concentrations in Scots pine needles were compared with the estimated distribution of atmospheric SO2. The total sulphur concentrations in the needles ranged from 741 to 2017 mg kg–1. Strongly elevated concentrations (> 1200 mg kg–1) were found within 40 km from the smelters corresponding to an area where the annual mean atmospheric SO2 concentration exceeded 10 g m–3. The foliar sulphur concentrations (total, organic and inorganic) show a high correlation with the estimated mean SO2 concentration distribution in the air. Consequently the foliar sulphur concentrations reflected the atmospheric sulphur load well. The data presented here show that uptake via stomata is an important deposition pathway also in the arctic conditions with a short growing season.  相似文献   

8.
The surface ozone (O3) data show an increase by 2.6 % per year during the period 1982–1994 at the rural site of Lithuania. WHO (World Health Organization), UN-ECE (United Nations Economic Commission for Europe), CES (Commission of the European Communities) guideline values for the protection of vegetation from adverse effects are exceeded during the growing season at the Preila coastal station. Ozone exposures for different concentration threshold are estimated during daylight hours in April-September. These values above 60 g/m3 varied between 10 000 and 43 000 (g/m3) ·h, above 80 g/m3 — between 1700 and 15 000 (g/m3) ·h, above 100 g/m3 — between 130 and 3700 (g/m3) ·h during separate years. Maximum hourly ozone values were observed from 116 to 228 g/m3 during this period.  相似文献   

9.
Zusammenfassung In der vorliegenden Arbeit werden Modelle für die Anreicherung des Kohlenstoffatoms12C gegenüber13C bei der Photosynthese von C3- und C4-Pflanzen beschrieben und im Zusammenhang mit Literaturdaten zum Einfluß innerer und äußerer Faktoren auf diesen Vorgang diskutiert. Bei den C3-Pflanzen wird die Isotopendiskriminierung durch das Verhältnis der Geschwindigkeiten des Transports von CO2 in das Blatt und der Carboxylierung des Ribulose-1,5-bisphosphats (RuBP) bestimmt. Ausdruck dieses Zusammenhangs ist eine vonFarquhar (1980) angegebene lineare Beziehung zwischen 13C-Wert und dem Verhältnis von interzellulärer und äußerer CO2-Konzentration. Die Isotopendiskriminierung bei der C4-Photosynthese ist ebenfalls von den Geschwindigkeiten der Diffusion von CO2 in das Blatt und der primären Carboxylierung von Phosphoenolpyruvat (PEP) abhängig. Wegen der unvermeidlichen Verluste von CO2 aus den Leitbündelscheidenzellen sind aber auch die sekundäre Carboxylierung von RuBP und der CO2-Transport innerhalb des Blattes zu berücksichtigen. Ein auf dieser Grundlage entwickeltes Modell, das im Gegensatz zu einem früher beschriebenen Ansatz auch die CO2-Abhängigkeit der Geschwindigkeitsparameter für die Carboxylierungsschritte einschließlich der Limitierung der PEP-Carboxylierung durch die PEP-Regenerationsrate berücksichtigt, wird ausführlich dargestellt. Nach diesem Modell können die wenigen bisher bekannten Befunde zum Einfluß hoher CO2-Konzentrationen auf die Isotopendiskriminierung von C4-Pflanzen als Hinweis darauf interpretiert werden, daß der Isotopeneffekt der RuBP-Carboxylierung bei den C4-Pflanzen möglicherweise größer ist als bei den C3-Pflanzen.
Models of carbon isotope discrimination during photosynthesis of C3 and C4 plants
Summary Models of fractionation of carbon atoms12C and13C during photosynthesis of C3 and C4 plants are described and discussed with regard to the influence of internal and external factors on this process. Isotope discrimination in C3 plants is determined by the ratio of the rates of CO2 transfer into the leaf and carboxylation of ribulose-1,5-bisphosphate (RuBP). This relationship can be expressed by a linear equation between 13C value and the ratio of intercellular and external CO2 concentration as proposed byFarquhar (1980). Carbon isotope discrimination by C4 photosynthesis also depends on the rates of CO2 diffusion into the leaf and of primary carboxylation of phosphoenolpyruvate (PEP). However, because of the unavoidable losses of CO2 from bundle sheath cells the secondary carboxylation of RuBP as well as CO2 transfer processes within the leaf must be taken into account, too. A model based on these features is explained in some detail. In contrast to a model proposed earlier the presented model considers the dependence on CO2 concentration of rate parameters for the carboxylation steps including limitation of PEP carboxylation by PEP regeneration rate. According to the model the spare experimental results on the influence of high concentrations of CO2 on carbon isotope discrimination in C4 plants may be interpreted as an indication that the isotope effect of RuBP carboxylation in C4 plants could be higher than in C3 plants.
3 - 4 -
12 13 3 4 , , . 3- 2 -1,5- (). , (1980), 13 2. 4 2 (). 2 , 2 . , , , , 2, . , , , 2 4-, , 4 -, , , 3-.
Herrn Prof. Dr.K. Unger anläßlich der 65. Wiederkehr seines Geburtstages gewidmet.  相似文献   

10.
Aerial photographs from 1970 and 1989 were used to assess the recovery of approximately 100000 ha of smelter-damaged lands near Sudbury, Canada. Recent improvements in air quality enabled conifers to recolonize about 22% of the semi-barrens, an area that consisted of a near monoculture of coppiced and stunted white birch (Betula papyrifera). The more heavily damaged barren areas, surrounding the three smelter sites, exhibited very little natural recovery during the study period. A municipal land reclamation program was responsible for most of the observed revegetation within the barren area. Between 1978 and 1988 approximately 2000 ha of barrens were reclaimed through soil treatment, grassing and tree planting. An estimated 7400 ha of the most heavily damaged land is still in need of immediate remedial treatment. Increased rates of natural recovery are expected in the future as SO2 emissions are reduced. Continued municipal and expanded industrial reclamation programs in the 1990s will also greatly reduce the extent of bare land.  相似文献   

11.
Zusammenfassung Aus getrockneten Blättern derLycopersicon-esculentum-Mutantenexilis (Ausgangssorte Condine Red) undprunoidea (Lukullus) wurden 0,40 bzw. 0,81% 1-Tomatin isoliert. Die Identifizierung des xylosefreien Alkaloidglykosids erfolgte durch Papierchromatographie und Untersuchung der bei Säurehydrolyse entstandenen Spaltprodukte. Blätter nicht mutierter Kontroll-pflanzen enthielten 0,64% bzw. 0,82% Tomatin.
Summary From dried leaves of two mutants ofLycopersicon esculentum Mill., namelyexilis (mutant of the variety Condine Red) andprunoidea (Lukullus), t-tomatine has been isolated in an amount of 0,40% and 0,81%, respectively. The identification of the xylose-free alkaloid glycoside was carried out by paper chromatography and investigation of the products formed by acid hydrolysis. Leaves of the non-mutated controls contained 0,64% and 0,82% tomatine, respectively.
exilis ( ) prunoidea () 0,40% 0,81% 1-. , . 0,64% 0,82% .

XXVIII. Mitteilung: Schreiber, K., Kulturpflanze11, 451–501 (1963); voranstehend.  相似文献   

12.
Zusammenfassung Die Gestaltung der Blütenregion einer spontan aufgetretenen, zweiblütigen Pflanze vom Sternblütigen Winterling,Eranthis hyemalis wird analysiert und beschrieben. Das die Nebenblüte tragende Parakladium entspringt der Achsel des unteren Involukralblattes.
Eranthis hyemalis (L.)Salisb. with a two-flowered stem
Summary Studies in the flower region of an exceptional spontaneously two-flowered stem of the Winter Aconite,Eranthis hyemalis. The shoot (paracladium) bearing the accessory flower arises from the axil of the outermost leaf of the involucre.
Eranthis hyemalis (L.)Salisb.
, , ,Eranthis hyemalis. , , .

Herrn Prof. Dr. Drs. h. c.Hans Stubbe zum 75. Geburtstag gewidmet.

Ich behalte gemäß Intern. Code, Art. 73 die vonLinné gewählte Schreibung bei, obgleich die klassische Form hiemalis seither weithin zu finden ist (s. aber z. B. Syllabus 1964,Clapham, Tutin andWarburg 1959,Lawalrée 1955).  相似文献   

13.
Zusammenfassung Mit Hilfe des Ultrarotabsorptionsschreibers (URAS) wurde die CO2-Konzentration in der bodennahen Luftschicht unter dem Einfluß von Wind und Windschutz gemessen. In der Nacht ist die CO2-Konzentration im Windschutz gegenüber dem Freiland erhöht, da dort die Atmungskohlensäure vor Verwehung geschützt ist. Bei unbewachsenem Boden bleibt jedoch in Lee die CO2-Konzentration durch Behinderung der Zufuhr aus der Umgebung geringer als in Luv. Für den Verlauf des Aufbaues eines CO2-Gefälles vom Boden her ist die Höhe der Windgeschwindigkeit bestimmend. Das rasche Absinken der CO2-Konzentration in den Morgenstunden muß zuerst durch die Photosynthese, die schon kurz nach Sonnenaufgang einsetzt, verursacht werden. Nach Erwärmung der untersten Luftschichten geht dann durch den Vertikalaustausch der größte Teil des während der Nacht angesammelten Kohlendioxyds den Pflanzen für die Photosynthese verloren. Am Tage besteht im Windschutz gegenüber dem Freiland meist ein CO2-Defizit, das zeitweise durch die erschwerte Erneuerung der Bestandesluft durch Advektion, in erster Linie jedoch durch die stärkere Assimilation der Pflanzen in Lee zustande kommt. Diese Mitteilung wird durch eine weitere ergänzt werden, welche das photosynthetische Verhalten von Pflanzen mit und ohne Windschutz behandelt.
CO2-content in the air layer above the ground with crop cultures in open field and under the lee
Summary By means of ultra-red absorption recorder (URAS) the CO2-concentration of the air near the ground under the influence of wind and wind shelter was investigated. During the night the CO2-concentration under the lee has been found increased in comparison with open field. Behind a shelter the CO2 is not so much blown away as outside. Indeed, above soil without any plant growth the CO2-concentration inside the sheltered area remains lower in consequence of the hindrance of horizontal transport of air. The wind speed is important to the formation of a CO2-gradient above the ground. The rapid decrease of CO2-concentration in the early morning must be caused primarily by photosynthesis of plants beginning almost immediately after sunrise. Later on by vertical air movement the greatest part of CO2, accumulated during the night, is lost for photosynthesis by warming the air near the ground. During the day under the lee there exist mostly a CO2-deficite in comparison with the open field. This is partly rendered by difficulty of air transport by advection, at first, indeed, by an increased rate of photosynthesis under the lee. The present communication will be continued by a second one concerning the photosynthetic behaviour of plants inside and outside of wind shelter.
CO2
, (URAS), CO2 . CO2 , , , , , . , , CO2 , . CO2 . CO2 , . , , , , . , , CO2, , . — .
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14.
Zusammenfassung In einer Übersicht wurden bis 1967 veröffentlichte Ergebnisse über einige biochemisch-physiologische Aspekte der Wirt-Parasit-Beziehungen zwischen Pflanzengeweben und Nematoden der GattungenHeterodera undMeloidogyne zusammengestellt. Dabei wurden vor allem berücksichtigt: 1. Methodische Möglichkeiten der pflanzlichen Organ- und Gewebekultur; 2. Bedeutung von Nematoden-Enzymen; 3. Wachstumsregulatoren und Gallinduktion; 4. Riesenzellbildung und -stoffwechsel; 5. der Mineralstoffwechsel im Wirt-Parasit-Komplex sowie 6. die Atmung nematodenbefallener Gewebe.
Summary A compilation has been given for some biochemical and physiological characteristics of host-parasit-relationships between plant tissues and nematodes of the generaHeterodera andMeloidogyne published up to 1967. Especially the following topics have been considered: 1. Usefulness of cultures of excised plant organs and tissues; 2. importance of nematode enzymes; 3. plant growth regulators and gall induction; 4. formation and metabolism of giant cells; 5. mineral nutrition within the host-parasit-complex; 6. respiration of plant tissues invaded by nematodes.
, 1967 ., - Heterodera Meloidogyne. : 1 — ; 2 — , ; 3 — ; 4 — ; 5 — -; 6 — , .

Übersicht nach einem Vortrag am 23. 6. 1967 im Institut für Pflanzenzüchtung Groß-Lüsewitz der Deutschen Akademie der Landwirtschaftswissenschaften zu Berlin.  相似文献   

15.
Zusammenfassung Über die alkaloidchemische Untersuchung von 68Solanum-Arten der UntergattungenArchaeosolanum Bitt. undLeptostemonum (Dun.) Bitt. sowie der SektionMorella (Dun.) Bitt. (UntergattungEusolanum Bitt.) wird ausführlich berichtet. Aus 40 Arten konnten Solasodin-glykoside (Solasonin, Solamargin,-Solamargin bzw. -Solanigrin) isoliert werden (Tabelle 1), so daß in Verbindung mit weiteren Literaturbefunden (Tabelle 2) nunmehr 67 solasodinführende Pflanzen bekannt sind.
Summary A report of the chemical examination of 68Solanum species for alkaloids is given. These species belong to the subgeneraArchaeosolanum Bitt. andLeptostemonum (Dun.) Bitt., as well as to the sectionMorella (Dun.) Bitt. of the subgenusEusolanum Bitt. From 40 species solasodine glycosides (solasonine, solamargine,-solamargine, -solanigrine) have been isolated (table 1). Together with the earlier literature (table 2) 67 solasodine containing plants are known up-to-date.
68 Solanum, Archaeosolanum Bitt.,Leptostemonum (Dun.) Bitt. Eusolanum Bitt. Morella (Dun.) Bitt. 40 : , ,- - (. 1). (. 2) , 67 , .

XXVII. Mitteilung: Schreiber, K., Kulturpflanze11, 422–450 (1963), voranstehend.

Auszug aus der Habilitationsschrift von K. Schreiber, Univ. Jena 1961; vorläufige Mitteilungen: Schreiber (1956, 1957a und 1958a), Schreiber und Mitarb. (1961).  相似文献   

16.
High-elevation red spruce-Fraser fir forests in the Southern Appalachian mountains: 1) receive among the highest rates of atmospheric deposition measured in North America, 2) contain old-growth forests, 3) have shown declines in forest health, 4) have sustained high insect-caused fir mortality, and 5) contain poorly buffered soils and stream systems. High rates of nitrogen and sulphur deposition (1900 and 2200 Eq·ha–1·yr–1, respectively) are dominated by dry and cloud deposition processes. Large leaching fluxes of nitrate-nitrogen (100–1400 Eq·ha–1·yr–1) occur within the soil profile. We have expanded the study to the watershed scale with monitoring of: precipitation, throughfall, stream hydrology, and stream chemistry. Two streamlets drain the 17.4 ha Noland Divide Watershed (1676–1920m) located in the Great Smoky Mountains National Park. A network of 50 20x20 m plots is being used to assess stand structure, biomass, and soil nutrient pools. Nitrate is the predominant anion in the streamlets (weighted concentrations: 47 and 54 eq·L–1 NO3 –; 31 and 43 eq·L–1 SO4 2–). Watershed nitrate export is extremely high (1000 Eq·ha–1 yr–1), facilitating significant base cation exports. Stream acid neutralizing capacity values are extremely low (–10 to 20 eq·L–1) and episodic acidifications (pH declines of a full unit in days or weeks time) occur. Annual streamwater sulfate export is on the order of 770 Eq·ha–1yr–1 or about one-third of total annual inputs, indicating there is net watershed sulfate retention. The system is highly nitrogen saturated (Stage 2, Stoddard, 1994) and this condition promotes both chronic and episodic stream acidification.  相似文献   

17.
Zusammenfassung Die morphologischen, ökologischen, phänologischen und geographischen Unterschiede der in Mittel-Europa auftretenden blaublühenden Sippe vonLithospermum arvense L. gegenüber der weißblühenden Normalform werden herausgearbeitet und ihre bis jetzt bekannten Fundorte zusammengestellt. Die Sippe (var.coerulescens DC.), die möglicherweise einen höheren Rang verdient, nimmt innerhalb des Formenkreises der Art eine ursprüngliche Stellung ein, während die weitverbreitete weißblühende Unkrautsippe abgeleitet erscheint. Der im einzelnen noch ungenau bekannte Formenreichtum der Art ist im südrussischen und vorderasiatischen Raum am größten. Die mitteleuropäischen Fundorte der var.coerulescens stellen weit nach Nordwesten vorgeschobene Ausläufer dort verbreiteter primärer Sippen vonLithospermum arvense L. dar.
Summary In Middle Europe a blue-flowered form ofLithospermum arvense L. sporadically occurs, the distribution of which has been described. Morphological, ecological, phenological and geographical differences are pointed out between this form and the common white-flowered one. This taxon (var.coerulescens DC.) seems to be more primitive than the widely distributed white-flowered weedy form ofLithospermum arvense L. Many forms ofLithospermum arvense L. occur from Southern Russia to the Near East, they are known only unsufficiently. The Middle European localities of var.coerulescens are the extremely Northwestern points of the area of the primary taxa ofLithospermum arvense L.
, , Lithospermum arvense L., , . . (var.coerulescens DC.), , , , . ; var.coerulescens - .
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18.
Zusammenfassung Die Heimat vonHelianthus tuberosus L. dürfte Mexiko sein, von wo aus sich die Kultur entlang der Ostküste Nordamerikas ausbreitete und besonders von den Indianerstämmen im Bereich der Mündung des St. Lorenz-Stromes gepflegt wurde.Die Einführung nach Europa erfolgte über romanische Länder. Nach Frankreich kam die Art 1607 aus Nordamerika. Die Holländer übernahmen sie 1613 aus Frankreich. Für andere europäische Länder läßt sich nur das Jahr der ersten Nachweisbarkeit feststellen (Italien 1614, England 1617, Deutschland 1626, Dänemark 1642, Polen 1652, Schweden 1658, Portugal 1661). Die Ausbreitung der Pflanze wird in den Rahmen der europäischen Kulturgeschichte gestellt. Wichtigster Ausgangspunkt der Verbreitung war Frankreich. Die Pflanze war Wegbereiter für den Anbau vonSolanum tuberosum L., der von England während der Aufklärungszeit ausging. — Die Entstehung der in einzelnen Ländern verwendeten Vernakulärnamen wird erläutert.
Summary The native country ofHelianthus tuberosus L. might be Mexico, from where the cultivation has spread along the Eastern coast of Northern America; the crop was especially important for the Indian tribes in the region of St. Lawrence River's mouth. — The introduction to Europe has happened by way of Romanic countries. France got this species in 1607 from Northern America. From here it was introduced to the Netherlands in 1613. For other European countries it is only possible to fix the year of the first statement in the literature (Italy 1614, England 1617, Germany 1626, Denmark 1642, Poland 1652, Sweden 1658, Portugal 1661). It has been described the expansion of the plant, which has been compared with the history of European culture. The most important starting-point of the expansion of Jerusalem's artichoke has been France. The plant prepared well the cultivation of the Irish potato which began in England during the Age of Enlightenment. — The origin of the vernaculare names, used in different countries forH. tuberosus, has been explained.
,Helianthus tuberosus L., , . . . . . 1607 . 1613. : 1614, 1617, 1626, 1642, 1652, 1658, 1661. . , , . — , .
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19.
Zusammenfassung 1. Die BlastocladialeAllomyces arbuscula, in Deutschland bisher nur von drei Fundorten angegeben (Remy 1950) wurde in einer Zone temporärer Pfützen am Rande einer gepflasterten Straße, wo auch die DesmidiaceeActinotaenium curtum (Bréb.)Teil. vorkommt, zwischen Gebäuden des Zentralinstitus gefunden.2.Tulipa sylvestris L. von einem Wild-Standort, wo sie sich wenig blühwillig zeigt, weist, in's Institutsgelände verpflanzt, starke vegetative Vermehrung und reichen Blütenansatz auf. Über auftretende Variationen im Blütenbau wird berichtet.
Some botanical observations in the area of the Institute
Summary 1. The BlastocladialeAllomyces arbuscula E. J. Butler 1911, known hitherto in Germany only from three sites (Remy 1950) was found on loamy soil from roadsides in the area of the Central Institute Gatersleben, together with the DesmidialeActinotaenium curtum (Bréb.)Teil. 1954.2. Observations on enhancement of floweriness and natural occurring aberrations in the flower formula fromTulipa sylvestris L. transplanted from a shaded wild site with very sparse producing flowers to gardenground with full sunshine.
1. Allomyces arbuscula, (Remy 1950), , , , Actinotaenium curtum (Bréb.)Teil.2. (Tulipa sylvestris L.), , , . .
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20.
Zusammenfassung Vaucheria prolifera Dangeard wird erstmalig für Mitteleuropa an zwei Fundorten im Harz nachgewiesen, in Rohkulturen gehalten und in Ergänzung der Artbeschreibung das Aussehen reifer, lebender Oosporen sowie deren Keimung beschrieben. Die Populationen aus dem Harz zeigen Besonderheiten in der Antheridienausbildung, die in Hinblick auf die beherrschende Rolle der Gametangien in der Systematik der Gattung diskutiert sind.
Contributions to the knowledge of the vaucheriaceae. XVII.Vaucheria prolifera Dangeard 1939 from the Harz Mountains
Summary A new station forVaucheria prolifera, the first in Middle Europe, is reported. The characters of the living, ripe Oospore and its germination are described. Some peculiar features of the antheridia in this population are discussed under the aspect of the dominating role the Gametangia play in the systematics of the genus.
Vaucheriaceae. XVII.Vaucheria prolifera Dangeard 1939
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Frau Prof. Dr. H.Sagromsky zum 60. Geburtstag gewidmet.  相似文献   

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