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Interactions among plant species via pollinators vary from competitive to mutualistic and can influence the probability of stable coexistence of plant species. We aimed to determine the nature of the interaction via flower visitors between Leucospermum conocarpodendron and Mimetes fimbriifolius, two shrubs in the Proteaceae that share many ecological traits and coexist on the Cape Peninsula, South Africa., To assess the extent of pollinator sharing we analysed nectar properties and recorded the pollinator fauna, their behaviour and contribution to seed set. To test for competition via interspecific pollen transfer, we recorded the movement patterns of pollinators and quantified pollen loads. To determine the effect of co-flowering on visitation rates we recorded visits in stands that varied in the density of the two species., We found that the species produce similar rewards and share pollinating Cape Sugarbirds ( Promerops cafer). Interspecific pollen transfer is avoided by placing pollen on different parts of the bird. Both species are visited by nectar-thieving Orange-breasted Sunbirds ( Anthobaphes violacea). Insects and autonomous self-pollination contributed little to seed set. Pollinator visits increased with conspecific density in both species, and the slope of the increase was steepest in the presence of high densities of the co-occurring plant species. Nectar thief visits also increased with conspecific density in both species, but the slope declined with increasing density of the co-occurring species., Co-occurrence enhanced pollinator visits and alleviated nectar robbing in both plant species, consistent with mutualisms. Mutualism within a trophic level is unusual, but may help to explain the stable coexistence of ecologically similar species. [ABSTRACT FROM AUTHOR]

Seed longevity, the control of dormancy and the eventual fate of seeds were studied in two experiments simulating conditions in natural fynbos. In one experiment a batch of mature, freshly harvested, intact achenes (“seeds”) of the myrmecochorous species Leucospermum cordifolium was divided into lots, of which one was buried in mesic mountain fynbos (experiencing a mediterranean-type climate with hot summers). Other seed lots were stored open at room temperature and in closed nitrogen filled containers at 3 °C, respectively. Stored seeds were sampled and germinated under optimal laboratory (viability estimate) and seed bed (vigour estimate in fynbos) conditions, during autumn, after 0 (control), 1, 2 and 4 years. Low temperature stored seeds maintained a high viability and vigour for c. two years but ambient temperature storage led to a marked decline after 1 year ending in almost complete mortality after 4 years of shelf storage. Four year soil-stored seeds, by contrast, maintained a high viability and vigour, of 80% and 60% respectively of the original seed source values. The soft pericarp/elaiosome in soil-stored seeds disappeared completely whilst the testa became progressively scarified over time. The strongly increased germination rate (velocity) in soil-stored seeds was attributed to natural oxygenation mediated by testa scarification. In another experiment freshly matured intact achenes were oxygenated with 1% H 2 O 2 and the pericarps removed. Disinfection and benzyladenine growth regulator soaking (200 mg L − 1 for 24 h) were applied as separate treatments. The seeds were then sown at 1 cm depth in a standard seed bed in autumn and germination was recorded in the first winter season and, in the undisturbed seed bed, in each subsequent winter for 5 germination seasons. H 2 O 2 oxygenated seeds gave a much higher germination percentage and rate than non-oxygenated seeds, although sporadic germination continued over five germination seasons in all treatments. Seeds germinated only during autumn and early winter each year. The results of the combined experiments suggest that, in nature, Leucospermum seeds can persist underground for long periods. We propose a model of soil-stored seeds in which the intact testa of freshly dispersed seeds is gradually scarified, leading to uneven, extended germination of the young (mainly current season) seed cohort over the first (and possibly several) post-fire germination seasons; and the synchronous germination of the older (scarified), larger, portion of the seed bank, leading to massive species recruitment during the early stages of the first post-fire winter germination season. The numerous wet–dry cycles due to natural rainfall, over prolonged periods in fynbos, may contribute to seed longevity via cellular repair processes. [ABSTRACT FROM AUTHOR]

Abstract: The effect of germination incubation regimes, which were chosen on the basis of temperature patterns found within the fynbos (Mediterranean fire-prone shrubland-type) habitat in the Cape Floristic Region during the autumn germinative period, was tested on seeds of 6 Leucospermum species over 5 taxonomic sections (L. cordifolium, L. cuneiforme, L. erubescens, L. glabrum, L. reflexum, L. vestitum ). Seeds of each species were scarified, soaked in water and incubated at 15 combinations of diurnal low (16h) and high (8h) temperatures. The results indicated that Leucospermum seeds generally require alternating temperatures for germination. Regression analysis of germination percentage responses were used to estimate provisional optimum low [T O(LOW)] and optimum high [T O(HIGH)] temperature requirements for individual species. These requirements differed markedly among species, and across species they averaged 9.9 and 21.2°C, respectively. Individual requirements correlated positively with mean late autumn air temperatures obtained from weather stations near the natural habitats of species. We conclude that a diurnal alternating temperature requirement is a character syndrome in Leucospermum in which the T O(LOW) and T O(HIGH) components are narrowly adaptive, independent and genetically stable characters relating to the known ecophysiological roles of low and high temperature requirements (Brits, Cutting, Brown and Van Staden, 1995). Ecological and adaptive roles of these requirements are compared with those in some persistent small-seeded soil-stored seed banks. [Copyright &y& Elsevier]

The family Proteaceae dominates the nutrient-poor, Mediterranean-climate floristic regions of southwestern Australia (SWA) and the Cape of South Africa. It is well-recognised that mediterranean Proteaceae have comparatively large seeds that are enriched with phosphorus (P), stored mainly as salts of phytic acid in protein globoids. Seed P can contribute up to 48% of the total aboveground P, with the fraction allocated depending on the species fire response. For SWA species, 70–80% of P allocated to fruiting structures is invested in seeds, compared with 30–75% for Cape species, with SWA species storing on average 4.7 times more P per seed at twice the concentration. When soil P is less limiting for growth, seed P reserves may be less important for seedling establishment, and hence plants there tend to produce smaller seeds with less P. For Australian Hakea and Grevillea species the translocation of P from the fruit wall to the seed occurs in the days/weeks before final fruit dry mass is reached, and accounts for 4–36% of seed P. Seed P content increases with the level of serotiny, though it decreases marginally as a fraction of the total reproductive structure. The greater occurrence of serotiny and higher seed P content within the Proteaceae in SWA supports the notion that SWA soils are more P-impoverished than those of the Cape. [ABSTRACT FROM AUTHOR]

The genus Pilonychiopus Meyer is re-defined and Austrostigmaeus Fan and Beard is relegated to its synonym. Pilonychiopus hallidayi n. sp., the third species in this genus, collected at Cape Town International Airport, South Africa from imported Leucospermum sp. (Proteaceae) originated in Australia, is described. A new genus, Farajimaeus, is created for Pilonychiopus tutus Meyer. A key to the genera and species of the family Stigmaeidae that lack tarsal claws is presented. Measurements of the type specimens of Pilonychiopus cliffortus Meyer and of F. tutus are provided as the original descriptions lacked these data. [ABSTRACT FROM AUTHOR]

A study of nutrient distribution in the flowering stem of proteas was carried out in commercial protea plantations of each of the cultivars 'Scarlett Ribbon', 'High Gold', 'Veldfire', and 'Sunrise' of Leucospermum cordifolium, and of the species L. patersonii located in a subtropical zone (La Palma Island, Canarian Archipelago). Flowering stems were cut into different parts: flower bud, leaves from half proximal stem to the flower bud, leaves from half distal stem to the flower bud, half proximal stem to the flower bud, and half distal stem to the flower bud. Nutrient content of the different parts of the flowering stems of the cultivar and the species gave significant differences in some cases, depending on the nutrient and the cultivar. Occasional dissimilarities among the levels of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), sodium (Na), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) were determined in comparisons among half proximal stems and half distal stems, independent of the cultivar. The same trend was observed when nutrient contents of the leaves from the half distal and the half proximal stems were compared. Phosphorus exhibited the lowest concentrations of all macronutrients in the different organs. Flower buds presented the smallest levels of macro-and micronutrients, while the leaves of the half distal and half proximal stems showed the highest values. The influence of nutrients of leaves from the half proximal stems on the stems length varied among cultivars. [ABSTRACT FROM AUTHOR]

Abstract: A study of soil physicochemical characteristics and mineral nutrition of four cultivars of Leucospermum cordifolium ('Scarlett Ribbon,' 'High Gold,' 'Veldifre,' 'Sunrise') and Leucospermum patersonii species was carried out along 2 years in commercial protea plantations, distributed throughout a subtropical region (La Palma Island, Canarian Archipelago). Soils presented a slightly acid pH range, whereas organic matter showed suitable values. Generally, available soil phosphorus (P) contents were less than 25 mg kg-1, with high available potassium (K) and calcium (Ca) levels, though the ratio of Ca of the sum of available cations was usually appropriate. Despite the high electrical conductivity (EC) levels (4.31-8.87 dS m-1) determined in some soils, no salinity symptoms were ever detected. Distribution and behavior of foliar nutrients nitrogen (N), P, K, Ca, magnesium (Mg), and sodium (Na) along time showed that nutritional needs varied in some cases among cultivars and species. L. patersonii presented the least N concentration, whereas 'High Gold' and 'Veldfire' had the greatest levels. Data denoted that P requirements were larger in younger plants, during the recovery after pruning, and while new buds developed. 'Sunrise' cultivar stood out for its large foliar levels of P, whereas 'Scarlett Ribbon' and 'Veldfire' had the least K contents. As a general pattern, K decreased in winter samplings. L. patersonii species and the cultivar 'Sunrise' exhibited the highest Ca values, and the same was true for Mg only in the species. A special need for Na appeared in all the cultivars and species studied. L. patersonii and the cultivar 'Sunrise' showed the greatest Na levels. A general stabilization of nutrient concentrations was observed in the fourth, fifth, and/or sixth samplings, so that November is recommended for taking samples for current foliar analysis. In this context, foliar ranges for the studied nutrients are suggested. [ABSTRACT FROM AUTHOR]

A study of nutrient removal was carried out in commercial protea plantations of each of the cultivars 'Scarlett Ribbon,' 'High Gold,' 'Veldfire,' and 'Sunrise' of Leucospermum cordifolium, and of the species L. patersonii,located in a subtropical region (La Palma, Canarian Archipelago). Flowering stems of optimal commercial quality were taken from each of the mentioned cultivars and species, once a year (2003 and 2004) at harvest time (January to April), and the different organs were analyzed separately. Flowering stems of the cultivars 'High Gold' and 'Veldfire' presented the highest contents of most studied nutrients, whereas the opposite was observed in 'Scarlett Ribbon' and L. patersonii. Mean yields of flowering stems varied very much among cultivars, and the highest ones were those of 'High Gold' and 'Scarlett Ribbon'. The cultivar 'High Gold' removed the highest quantities of studied nutrients, and the contrary was observed in L. patersonii for most of them. Suitable rates of nitrogen (N): phosphorus (P): potassium (K) fertilizers for nutrient restitution purposes were 1:0.08:0.40 for 'Scarlett Ribbon,' 1:0.08:0.66 for 'High Gold,' 1:0.08:0.38 for 'Veldfire,' 1:0.09:0.75 for L. patersonii;and 1:0.18:1.11 for 'Sunrise'. [ABSTRACT FROM AUTHOR]

The ability of orthodox seeds to survive long-term dry storage is a key prerequisite for ex situ seed conservation in genebanks. However, only a few credible observations of seed survival for ≥ 200 years have been reported. In this paper, seed survival is shown for three species under suboptimal storage conditions for a documented time of ≥ 203 years and carbon dated at 218–270 years. Two species that germinated are in the Fabaceae (Liparia sp. and Acacia sp.). A water-impermeable seed coat, and hence an inability to equilibrate with ambient relative humidity, may contribute to long-term survival of these species. The third species that germinated (Leucospermum sp.) does not have a water-impermeable seed coat, and long-term survival may be linked to an oxygen-impermeable barrier in the seed. These results for species from the Cape Floristic Region, South Africa, suggest adaptation for extreme longevity in seeds of species of seasonally dry, Mediterranean environments. [ABSTRACT FROM PUBLISHER]

Abstract: Foliar samples, SPAD-502 measurements (both along the growing season), and soil samples were taken from protea plants (Leucospermum cordifolium), cultivar ‘High Gold’ cultivated in six commercial plantations of La Palma Island (Canarian Archipelago). Soil data (pH, available P, Ca, Mg, K and Na, and EC) ranged within normal levels for proteas, though O.M. was high. Drainage decreased the potential problem that could be caused by the high clay content of the soils. Leaves showed high concentrations of N, K, Mg, and Na, while Ca and Cu were normal. On the other hand, Fe and Zn presented some low foliar levels, while Mn values fluctuated depending upon the different plantations. N contents were higher in spring, and those of K, Ca, Mg, and Na increased with time. Relative chlorophyll contents (SPAD-502 measurements) were compared with macro- (N, P, Na, K, Ca, Mg) and micro- (Cu, Fe, Mn, Zn) foliar levels. Results showed no positive correlation between leaf chlorophyll and N content. Higher leaf N concentrations were observed in chlorophyll deficient than chlorophyll sufficient leaves at one site and vice versa at another site. In contrast, lower Mn, Fe and Ca concentrations, the last corresponding with higher ratios of N/Ca were observed in chlorophyll deficient than chlorophyll sufficient leaves at several sites. It is concluded that amendment of soils with Mn, Fe and Ca may prevent the development of chlorophyll deficiency symptoms, associated with diminished photosynthetic capacity, in this important commercial cultivar. [Copyright &y& Elsevier]

Abstract: Leukocytospermia is frequent and significantly increased (over 106/ml) in 20% of male factor infertility. It induces the production of highly toxic reactive oxygen species (ROS) which impair genital track accessory glands and sperm cell functions. The seminal medium contains extremely potent antioxidative defenses which usually balance the oxidative stress. In vivo, these defenses can be overwhelmed when ROS production is extremely important and/or when it lasts for a very long period of time. Infertility can then appear. In vitro, ROS have been univoqually demonstrated for being highly toxic since spermatozoa are no longer protected. Sperm cell defects are : decrease of acrosome reaction and fusiogenic ability and increase of DNA fragmentations. In case of male factor infertility, a leukocytospermia represents an essential or an additional risk factor that should be treated, specially when in vitro therapy is to be scheduled, in order to improve gamete quality. [Copyright &y& Elsevier]

In moving seeds from one location to another, dispersers define the ecological context that a plant will experience throughout its lifetime. Because seed deposition sites may benefit one plant life cycle stage but not others, dispersal may give rise to a conflict between a plant's dispersal needs (e.g., predator escape) and its requirements for successful establishment (e.g., suitable habitat). In this study, we assessed the effects of two components of seed dispersal by ants (seed burial depth and elaiosome removal) at several stages during the recruitment of Leucospermum truncatulum, an ant-dispersed plant from the fynbos shrublands of South Africa. A seed-predator exclusion experiment revealed that the removal of elaiosomes significantly reduced rodent predation on seeds buried 1 cm deep and increased the viability of seeds that were not consumed. In contrast, we found that elaiosomes had no effect on the probability of a living seed emerging as a seedling. In a seed burial depth experiment in which predators were not excluded, deeper burial significantly enhanced seed survival, but this benefit came at the expense of reduced seedling emergence, delayed emergence, and smaller cotyledon size. Despite the potential importance of these seedling characteristics, elaiosomes and burial depth had no significant effect on seedling survival through the first year of this study. In contrast, burial depth had strong positive effects on the fraction of seeds that persisted in the seed bank. Although dormant individuals may die before germinating and reproducing, those that persist at greater soil depths can play a crucial role in rescuing populations from local extinction in unpredictable environments. Given the extreme variability in fire frequency in fynbos, the net effect of seed dispersal by ants on plant populations will depend on how temporal fluctuations in fire regimes influence cost-benefit thresholds related to seed dormancy and seed mortality. [ABSTRACT FROM AUTHOR]

Studies the effects of a complete factorial fertilizer addition of nitrogen, phosphorus and mixture of all essential nutrients excluding nitrogen and phosphorus on production, dry mass, nitrogen and phosphorus contents of inflorescences and seeds of the evergreen shrub, Leucospermum parile in Cape Province, South Africa for two years. Reduction of inflorescence number per shrub with nitrogen addition in the first year; Control of the resource allocation to seed production.

A new seed biological phenomenon in the myrmecochorous, fire-recruiting fynbos species Leucospermum cordifolium (Salisb. ex Knight) Fourcade is reported. This is the extensive breaking, following desiccation treatment, of the seed testa which in intact, soil-stored seeds imposes dormancy on the embryo by means of oxygen exclusion. In this study the pericarps of L. cordifolium seeds were removed and seeds with intact exotestas were selected stereomicroscopically. Samples of seeds were placed in nylon bags and suspended over (conc.) H[sub2]SO[sub4] or dried silica gel. A third series of seeds were exposed for varying periods to 40 °C, cooled and immersed in water before performing breakage tests on both the exo- and endotesta. All treatments resulted in extensive breaking of the exo- as well as the endotesta of seeds. The two `cool' desiccating treatments both caused more effective breaking than heat treatments. This indicates strongly that the breakage phenomena are desiccation effects and not caused directly by heat intensity. Rehydration in air before wetting seeds completely prevented breakage effects in all treatments in the endotesta, but not in the exotesta. This further supports the conclusion that endotesta breakage is a function of desiccation plus wetting and not of heat per se. The results suggest that in nature desiccation by fire could break the exotesta and the endotesta as well, if fire is followed soon by rain. These effects amount to effective scarification of the seed and thus suggest a positive correlation, in nature, between heat intensity of fire and emergent seedling numbers. [ABSTRACT FROM AUTHOR]

The distribution of dry mass and phosphorus (P) in the proteoid shrub, Leucospermum parile (Salisb. ex J. Knight) Sweet, was determined at three stages of development following fire, over one year in coastal fynbos vegetation, South Africa. At the seedling stage, a mobilization of P was observed from the hypocotyl and cotyledons to the canopy (40% of total P). The numbers and dry mass of proteoid roots increased between eight and ten months after the fire when there was an apparent decline in total seedling P. The one- to two-year-old plants showed rapid vegetative growth, the leaves being the major storage organs for P. In the final stage of development (five- to six-year-old plants), flowering and seed production caused a reduction in P levels in the non-reproductive parts of the plant and up to 20 % of the total P accumulated in the inflorescences. There was a winter peak in root production and P content for one- to two-year-old plants which had root/shoot ratios of 0.77 and 0.48 respectively; the ratio fell to below 0.2 in the five- to six-year-old plants. The non-mycorrhizal root systems of L. parile are dominated by the tap root (up to 88% of total root) but the majority of the roots within the rhizosphere were from neighbouring species. [ABSTRACT FROM AUTHOR]

Cover: Tree pincushion ( Leucospermum conocarpodendron viridum), a member of the family Proteaceae and the largest member of its genus, Cape of Good Hope National Park, South Africa. On pages 593-601, Tucker et al. explore differences in the species richness, phylogenetic diversity, and evolutionary distinctiveness of Proteaceae species in the Cape Floristic Region of South Africa. They found that species richness and phylogenetic diversity typically were highly correlated, but sites with high phylogenetic diversity were more spatially extensive than sites with high species richness. Rare species generally had high levels of evolutionary distinctiveness. Sites near the southern edge of the Cape Floristic Region were occupied by species with high levels of evolutionary distinctiveness and limited geographic ranges, but those sites were not assigned high conservation-priority rankings on the basis of species richness or phylogenetic distinctiveness. Photographer: Photographer and conservationist Jaime Rojo () believes visual storytelling is a powerful tool for conservation. Since moving to Mexico from his native Spain 8 years ago, Jaime has worked with diverse environmental nongovernmental organizations while developing his career as a photographer. He has participated in numerous conservation initiatives including the promotion of El Carmen Big Bend Conservation Corridor, a transboundary protected area along the border between Mexico and the United States; a campaign to protect the San Pedro Mezquital, the last free-flowing river in the western Sierra Madre; and the celebration of WILD9, the ninth World Wilderness Congress, for which he was executive director in Mexico. Rojo is a trustee of Th e WILD Foundation and an associate of the International League of Conservation Photographers. [ABSTRACT FROM AUTHOR]

Cover description: The Silver-edge Pincushion ( Leucospermum patersonii) occurs on limestone soils in the Agulhas region at the southern tip of Africa. It is one of 381 taxa of Proteaceae which occur in the species-rich Fynbos Biome of the Cape Floral Kingdom. They were the focus of a 10-year atlas project ( ) involving over 500 amateurs on the subcontinent, who collected over 250 000 records from 65 000 localities. For over 15 years proteas have been used to guide systemic and objective conservation planning and management in the region. Photo: Justine Grantham. [ABSTRACT FROM AUTHOR]