Proposals for a Sangay National Park in Ecuador

This paper describes the main features of the Sangay wilderness area in the Ecuadorian Andes. It is a region of great diversity with life zones ranging from tundra to subtropical rain forest. The conservation value of the area is assessed and the feasibility of protection determined. Boundaries based mainly on the limits of human interference are put forward with management proposals for its establishment as a National Park.     

The effect of propionic acid on the storage losses of hay

Storage losses in moist hay treated with propionic acid were compared with those occurring in untreated moist hay in two experiments and with field-cured hay in three experiments. Dry matter losses in treated hays ranged from 41 to 8.6% and from 1.7 to 12.6% in untreated hays. Digestible organic matter losses in both treated and untreated hays were generally greater than dry matter losses. Only in one experiment did propionic acid application significantly reduce nutrient losses in moist hays. Nutrient losses, and water-soluble carbohydrate losses in particular, were shown to be correlated with maximum and cumulative bale temperatures during storage in two of the experiments. The rise in hale temperatures during storage was reduced in all three experiments, to a greater or lesser extent, by application of the additive. Loss of propionic acid from the hay during and after application was very large. In the three experiments 86.2, 85.3 and 85.6% of the acid applied was lost by the end of the storage period. Acid distribution studies indicated that variation in acid concentration within bales was as great as between bales. It was concluded that more research is needed into applicator design and position on the baler and into alternative application methods if the benefits of propionic acid as a moist hay preservative are to be fully exploited.     

Nitrogen fixation by white clover in hill pasture

An experiment is described in which the amount of nitrogen fixed by the white clover component of a surface-sown hill sward was determined using small quantities of ¹⁵N-labelled ammonium sulphate. Between 11 July and 22 August 1974 25 kg ha^?1 N was fixed. No evidence of a transfer of N from clover to the associated perennial ryegrass was detectable over this period although the N content of the grass growing with the clover was higher. The relative advantages of the isotope technique and the acetylene reduction assay are discussed.     

THE ELECTRONIC MEASUREMENT OF SMALL HERBAGE YIELDS USING A HIGH SENSITIVITY CAPACITANCE METER

The capacitance meters available in the past for estimating herbage yields have lacked sensitivity at the extremes of their range of measurement. The preliminary evaluation of a highly sensitive capacitance meter described here indicates that accurate measurement is possible in the range 0.1100 kg DM/ha. The implications of this development for the measurement of herbage of low availability are discussed.     

The potato in hakluyt

Summary Richard Hakluyt (ca. 1553–1616) collected together and published first-hand accounts of the voyages of English seamen, including several 16th century voyages to South America. These accounts provide some of the earliest published references to the potato, but unfortunately they make no mention of its introduction into Europe.     

Chemical Aids in Forest Fire Control

Progress in development of chemical aids in suppressing andretarding forest fires and in drying vegetation to facilitatecontrolled burning is reviewed briefly. The main part of thepaper describes exploratory trials in 1958–61, using arange of fire-retardant compounds for control of grass and heathfires. All chemicals tested were markedly superior to plainwater in checking fire spread. Ammonium phosphate solution,and ‘viscous water’ prepared using sodium alginate,were the most promising retardants tested, the latter beingthe more effective on heavier fuels such as heather and gorse.The costs and mechanics of use are discussed. Subject to operationaltrials, it is concluded that these chemicals could be of practicalvalue in checking the front and hottest parts of vegetationfires. Recent trials suggest that herbicides, of those testednotably Paraquat, may be used to desiccate grass vegetationto permit safe and rapid controlled burning during summer months.     

The respiration of developing potato tubers

Summary The rate of O₂-uptake and CO₂-output, at 10°C., of tubers (var.Majestic) soon after they were formed at the end of June was about 50 ml/kg/hr, and fell during development to final values, before the death of the foliage, of the order of 4–5 ml/kg/hr. The quotient CO₂/O₂ remained within the range 0,85–1,19. The respiration of the tubers per plant calculated for field temperature, rose from about 6–7 ml/hr at the end of June to a peak value of 25–30 ml/hr in mid-August and thereafter fell. The results given here, coupled with observations on foliage respiration, and on the effect of temperature on respiration, suggest that increased respiration plays only a minor part in the reduction in yield which is observed at high temperatures. The mechanism of this reduction is discussed.

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Zusammenfassung Die O₂-Aufnahme und CO₂-Abgabe bei 10°C durch Knollen der SorteMajestic belief sich kurz nach ihrer Bildung am Ende Juni auf ungef?hr 50 ml/kg/Std. und field w?hrend der Weiterentwicklung bis zum Absterben des Krautes auf den Endwert 4–5 ml/kg/Std. (abb, 1 und 2). Der Quotient CO₂/O₂ blieb innerhalb des Bereiches von 0,85–1,19. Die Atmung aller Knollen pro Pflanze — berechnet für Feldtemperaturen — stieg von ungef?hr 6–7 ml/Std. Ende Juni auf einen H?chstwert von 25–30 ml/Std. um Mitte August, wenn die Knollen sich ihrer maximalen Gr?sse n?herten oder sie erreicht hatten, aber immer noch mit dem Blattwerk verbunden waren. Nachher fielen die Werte für die Atmung der Knollen pro Pflanze. Die Erstellung einer Kohlenstoffbilanz ergab ungef?hr, dass in der Mitte der aktivsten Periode des Knollenwachstums im Jahr 1961 die durchschnittliche t?gliche, von der Pflanze assimilierte Menge von CO₂ etwa 14 g betrug. Davon wurden zirka 13% in die Trockensubstanz des Krautes eingebaut, etwa 7% wurden durch das Kraut veratmet und der Rest in die unterirdischen Teile abgeführt, wo weitere 2% für das Wachstum und die Atmung der Wurzeln und ungef?hr 7% für die Atmung der Knollen verbraucht wurden. Etwas mehr als 70% gelangten in die Trockensubstanz der Knollen. Die hier wiedergegebenen Resultate, verbunden mit Beobachtungen über die Wirkung der Temperatur auf die Atmung, deuten an, dass erh?hte Atmung nur von geringerer Bedeutung ist für die bei hohen Temperaturen beobachtete Verminderung des Ertrags. Die Art und Weise dieser Ertragseinbusse wird besprochen.

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Résumé Les quantités d'oxygène (O₂) absorbées et d'anhydride carbonique (CO₂) exhalées à 10°C, par des tubercules de la variétéMajestic sit?t après leur formation à la fin juin est d'environ 50 ml/kg/h; ces quantités tombent durant le développement, avant la mort du feuillage, à des valeurs finales de l'ordre de 4–5 ml/kg/h (fig. 1 et 2). Le rapport CO₂/O₂ restait dans les limites 0,85–1,19. La respiration des tubercules d'une plante, calculée à la température du champ, s'élevait de quelque 6–7 ml/h à la fin juin, à la valeur maximum de 25–30 ml/h à la mi-ao?t, au moment où les tubercules avaient atteint ou presque leur grosseur maximum mais étaient encore attachés à un feuillage en fonctionnement. Après cela, la respiration des tubercules d'une plante diminuait. Un bilan approximatif du carbone indiquait qu'à la moitié de la période la plus active de croissance du tubercule, en 1961, la quantité moyenne journalière de CO₂ assimilée par la plante était d'environ 14 g. De ceux-ci, 13% environ sont incorporés dans la matière sèche des fanes, quelque 7% sont utilisés dans la respiration des fanes, le restant étant transféré dans la partie souterraine; 2% sont alors utilisés dans la croissance et la respiration des racines, 7% environ dans la respiration des tubercules et 70% au moins sont incorporés dans la matière sèche des tubercules. Ces résultats et ceux provenant d'observations sur l'effet de la température sur la respiration suggèrent que l'accroissement de la respiration joue seulement un r?le mineur dans la réduction de rendement observée à hautes températures. Le mécanisme de cette diminution de rendement est discuté.