Breeding plantation tree crops: v.1: Temperate species; v.2: Tropical species

2009 ◽  
Vol 46 (11) ◽  
pp. 46-6194-46-6194
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. J. H. Nati ◽  
M. B. S. Svendsen ◽  
S. Marras ◽  
S. S. Killen ◽  
J. F. Steffensen ◽  
...  

AbstractHow ectothermic animals will cope with global warming is a critical determinant of the ecological impacts of climate change. There has been extensive study of upper thermal tolerance limits among fish species but how intraspecific variation in tolerance may be affected by habitat characteristics and evolutionary history has not been considered. Intraspecific variation is a primary determinant of species vulnerability to climate change, with implications for global patterns of impacts of ongoing warming. Using published critical thermal maximum (CTmax) data on 203 fish species, we found that intraspecific variation in upper thermal tolerance varies according to a species’ latitude and evolutionary history. Overall, tropical species show a lower intraspecific variation in thermal tolerance than temperate species. Notably, freshwater tropical species have a lower variation in tolerance than freshwater temperate species, which implies increased vulnerability to impacts of thermal stress. The extent of variation in CTmax among fish species has a strong phylogenetic signal, which may indicate a constraint on evolvability to rising temperatures in tropical fishes. That is, in addition to living closer to their upper thermal limits, tropical species may have higher sensitivity and lower adaptability to global warming compared to temperate counterparts. This is evidence that freshwater tropical fish communities, worldwide, are especially vulnerable to ongoing climate change.


1988 ◽  
Vol 28 (6) ◽  
pp. 729 ◽  
Author(s):  
DE Margan ◽  
NM Graham ◽  
DJ Minson ◽  
TW Searle

Artificially dried grass of 2 tropical species (Setaria spacelata and Digitaria decurnbens) from which most of the stem had been removed, and a temperate grass (Loliurn perenne) grown under the same subtropical conditions, were compared for energy and protein value. Data for a temperate clover hay (Trifolium resupinatum) that was tested concurrently are included because they provide useful contrasts. Each was evaluated by measuring energy, nitrogen (N) and carbon balances in 4 adult sheep at 2 levels of intake (ad libitum and near energy maintenance) and during fasting. The 3 grasses had similar leaf content (76-83%) and the clover much less (60%). The tropical forages had similar chemical composition but they contained less crude protein (10%) than the ryegrass (L. perenne) (1 5%) and more cell wall constituents (63-66% v. 58%). The clover had the most crude protein (19%) and the least cell walls (38%); it also was highest in carbohydrates, pectin and heat of combustion. Voluntary intakes of the setaria, pangola (D. decumbens) and ryegrass were similar and 20-30% lower than the intake of clover. Digestibilities of dry matter (DM), organic matter (OM) and energy were similar for the grasses and 8 percentage units lower than for the clover whereas digestibility of crude protein differed between the tropical and temperate species, the latter having digestibilities 12-15 units greater. Digestibility of cell walls did not vary. The metabolisable energy (ME) values of the grasses at maintenance were 8.3-8.5 MJ/kg DM while that of clover was 10.1; at maximum intakes, corresponding ME values were 7.9 and 10.0 MJ/kg DM. Net availability of ME for gain was 0.42 for the tropical grasses and the persian clover and 0.36 for the ryegrass. By contrast, the tropical forages supported higher gains of N relative to N supply than did the temperate forages because urinary N loss was not affected by intake of the tropicals; these differences in N gain were drastically reduced when gain was expressed in relation to ME. These results do not support the contention that forages of tropical species have a lower energy value per kg than temperate forages of similar composition. Indeed, the tropical species tested here appear to have had an ideal balance of energy and protein insofar as efficiency of use of digestible N was close to 100% and their energy values were commensurate with their chemical composition.


1981 ◽  
Vol 21 (111) ◽  
pp. 410
Author(s):  
KF Lowe ◽  
TM Bowdler ◽  
JC Mulder

The most effective time to sow irrigated perennial pastures containing tropical and temperate species was investigated over three years at Gatton, south-eastern Queensland. Three mixtures were sown each month between September and June and in split sowings where the tropical species were sown in September or March, and the temperate species in May. Autumn sowings produced the most seedlings of sown species 40 d after sowing. Of the autumn months, May was the most suitable, with an establishment of 181 plants/m2 and a weed population of only 19 plants/m2. Tropical grass establishment was less than 8 plants/m2 from all sowing times. A considerable proportion of tropical grass sown in autumn appeared in spring. Split sowings were not as effective as autumn sowings and favoured the tropical species, which were sown first. Dry matter yield of sown species in the establishment year varied from 0.9 t/ha for February sowings to 12.0 t/ha for April sowings; weed yields varied from 5.8 t/ha for September sowings to 0.8 t/ha for May sowings. Tropical grass contribution was greatest from the split sowing in which the tropical species were sown in September. Temperate species yields were highest from May sowings. In the second year yields of temperate species declined substantially, mainly because of poor persistence of ryegrass. Although tropical grass yields increased in all treatments, this increase was not sufficient in the autumn sowings to compensate for the low ryegrass yields.


2009 ◽  
Vol 104 (6) ◽  
pp. viii-ix
Author(s):  
Françoise Dosba
Keyword(s):  

2014 ◽  
Vol 92 (9) ◽  
pp. 749-770 ◽  
Author(s):  
Mari Kuroki ◽  
Michael J. Miller ◽  
Katsumi Tsukamoto

Early life-history traits of all 19 anguillid eel species and subspecies were examined to help understand the evolutionary processes of their oceanic migrations in comparison with their migration distances and the geography of their species ranges. Tropical species were found to have fewer myomeres, greater body depths, higher growth rates, shorter larval durations, and smaller maximum larval sizes than temperate species. The relationships among larval characteristics such as growth rate, age at metamorphosis, and maximum larval size differed among tropical and temperate species and corresponded with the maximum latitudes of their species ranges. Temperate eel leptocephali with slow growth and large maximum size with slender bodies appear to be specialized for long migrations and dispersal over a wide range of distances to higher latitudes, while having flexible sizes of metamorphosis and recruitment. Tropical species with faster growth metamorphose earlier at a relatively fixed size, which would facilitate larval retention near their species ranges at low latitudes. Changes in the early life-history traits of tropical eels appear to have occurred during the evolution of longer migrations as they entered temperate regions.


1970 ◽  
Vol 32 (2) ◽  
pp. 189-195
Author(s):  
Po-Teen Lim ◽  
Chui-Pin Leaw ◽  
Shinnosuke Kaga ◽  
Katsushi Sekiguchi ◽  
Takehiko Ogata

Growth response of five clonal cultures of Alexandrium obtained from tropical and temperate waters were examined. Experiments were carried out in eighteen variable temperature-salinity conditions (temperatures of 15 °C, 20°C, and 25°C; salinities between 5 to 30 psu) under constant illumination of 150 ± 10.0 Amol m-2 s-' at 15:9 light:dark photo-cycle. Our results showed optimum growth of all Alexandrium species at 20 - 25°C. The salinity range for optimum growth however varied among the species. Growth rates of A. eine, A. insuetum, and A. fraterculus (0.28 — 0.37 day') were higher than those of A. leei and A. pseudogoniaulax under the same culture conditions (0.14 —0.22 day-'). The three temperate species showed positive growth at suboptimum temperature, 15°C, but the tropical species did not grow and died off. Salinity tolerance of the five species in decreasing order was A. pseudogoniaulax > A. leei > A. insuetum > A. affine > A. fraterculus. Results of the present study showed vast variations in salinity tolerance among the Alexandrium species regardless the geographical origins. Adaptation of the temperate species at higher temperature indicated that the species might proliferate in warm tropical waters.


1987 ◽  
Vol 65 (10) ◽  
pp. 2349-2353 ◽  
Author(s):  
Janet W. Goldblatt ◽  
Richard D. Fell

We studied worker longevity in two colonies of Bombus fervidus (F.) and two colonies of Bombus pennsylvanicus (De Geer). In 1981, adult life expectation for B. fervidus workers was 21.8 days. In 1982, mean expectation of life at adult emergence was 34.1 days for workers of B. fervidus and 33.0 days for workers of B. pennsylvanicus. The longevities observed in 1982 are the highest yet recorded for temperate bumble bee species, and are intermediate between the previously described extremes of short life-span in north temperate species and high longevity in a tropical species. This study suggests that bumble bee life expectancy tends to decrease as one progresses northward. However, variation in life expectancy within B. fervidus at a single location in two consecutive years was almost as great as previously described differences in longevity between tropical and temperate species. Shortened life-span may therefore be associated with increased intensity of foraging activity during periods of low forage availability as well as with latitude. In both years, survivorship of late-emerging worker cohorts was consistently low, possibly because a larger proportion of late-emerging workers become foragers.


Bothalia ◽  
2006 ◽  
Vol 36 (2) ◽  
pp. 201-222 ◽  
Author(s):  
L. Henderson

A subset of invasive alien plant species in southern Africa was analysed in terms of their history of introduction, rate of spread, countries/region of origin, taxonomy, growth forms, cultivated uses, weed status and current distribution in southern Africa, and comparisons made of those originating from south of the tropic of Capricorn, north of the tropic of Cancer and from the tropics. The subset of 233 species, belonging to 58 families, includes all important declared species and some potentially important species. Almost as many species originate from temperate regions (112) as from the tropics (121). Most southern temperate species came from Australia (28/36), most tropical species from tropical America (92/121) and most northern temperate species from Europe (including the Mediterranean) and Asia (58/76). Transformers account for 33% of  all species. More transformers are of tropical origin (36) than of northern temperate (24) and southern temperate origin (18). However. 50% of southern temperate species are transformers, compared to 32% of northern temperate and 29% of tropical species. Southern temperate transformer species are mainly woody trees and shrubs that were established on a grand scale as silvicultural crops, barriers (hedges, windbreaks and screens) and cover/binders. Most aquatics, herbs, climbers and succulent shrubs an. trom the tropics. Ornamentals are the single largest category of plants from all three regions, the tropics having contributed twice as many species as temperate regions.


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