What lies beneath? : The pattern and abundance of the subterranean tuber bank of the invasive liana cat’s claw creeper, Macfadyena unguis-cati (Bignoniaceae)

Cat’s claw creeper, Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) is a major environmental weed of riparian areas, rainforest communities and remnant natural vegetation in coastal Queensland and New South Wales, Australia. In densely infested areas, it smothers standing vegetation, including large trees, and causes canopy collapse. Quantitative data on the ecology of this invasive vine are generally lacking. The present study examines the underground tuber traits of M. unguis-cati and explores their links with aboveground parameters at five infested sites spanning both riparian and inland vegetation. Tubers were abundant in terms of density (~1000 per m2), although small in size and low in level of interconnectivity. M. unguis-cati also exhibits multiple stems per plant. Of all traits screened, the link between stand (stem density) and tuber density was the most significant and yielded a promising bivariate relationship for the purposes of estimation, prediction and management of what lies beneath the soil surface of a given M. unguis-cati infestation site. The study also suggests that new recruitment is primarily from seeds, not from vegetative propagation as previously thought. The results highlight the need for future biological-control efforts to focus on introducing specialist seed- and pod-feeding insects to reduce seed-output.

Structural characteristics of a giant tropical liana and its mode of canopy spread in an alien environment

To circumvent the practical difficulties in research on tropical rainforest lianas in their natural habitat due to prevailing weather conditions, dense camouflaging vegetation and problems in transporting equipment for experimental investigations, Entada pursaetha DC (syn. Entada scandens Benth., Leguminosae) was grown inside a research campus in a dry subtropical environment. A solitary genet has attained a gigantic size in 17 years, infesting crowns of semi-evergreen trees growing in an area roughly equivalent to 1.6 ha. It has used aerially formed, cable-like stolons for navigating and spreading its canopy across tree gaps. Some of its parts which had remained unseen in its natural habitat due to dense vegetation are described. The attained size of this liana in a climatically different environment raises the question as to why it is restricted to evergreen rainforests. Some research problems for which this liana will be useful are pointed out.

Control of the invasive liana, Hiptage benghalensis

The liana, hiptage (Hiptage benghalensis), is currently invading the wet tropics of northern Queensland and remnant bushland in south-eastern Queensland, Australia. Trials using seven herbicides and three application methods (foliar, basal bark, and cut stump) were undertaken at a site in north Queensland (158 700 hiptage plants ha−1). The foliar-applied herbicides were only effective in controlling the hiptage seedlings. Of the foliar herbicides trialed, dicamba, fluroxypyr, and triclopyr/picloram controlled >75% of the treated seedlings. On the larger plants, the cut stump applications were more effective than the basal bark treatments. Kills of >95% were obtained when the plants were cut close to ground level (5 cm) and treated with herbicides that were mixed with diesel (fluroxypyr and triclopyr/picloram), with water (glyphosate), or were applied neat (picloram). The costings for the cut stump treatment of a hiptage infestation (85 000 plants ha−1), excluding labor, would be $A14 324 ha−1 using picloram and $A5294 ha−1 and $A2676 ha−1, respectively, using glyphosate and fluroxypyr. Foliar application using dicamba for seedling control would cost $A1830 ha−1. The costs range from 2–17 cents per plant depending on the treatment. A lack of hiptage seeds below the soil surface, a high germinability (>98%) of the viable seeds, a low viability (0%) of 2 year old, laboratory-stored fruit, and a seedling density of 0.1 seedlings m−2 12 months after a control program indicate that hiptage might have a short-term seed bank. Protracted recolonization from the seed bank would therefore be unlikely after established seed-producing plants have been controlled.

What lies beneath? The pattern and abundance of the subterranean tuber bank of the invasive liana cat's claw creeper, Macfadyena unguis-cati (Bignoniaceae)

Cat’s claw creeper, Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) is a major environmental weed of riparian areas, rainforest communities and remnant natural vegetation in coastal Queensland and New South Wales, Australia. In densely infested areas, it smothers standing vegetation, including large trees, and causes canopy collapse. Quantitative data on the ecology of this invasive vine are generally lacking. The present study examines the underground tuber traits of M. unguis-cati and explores their links with aboveground parameters at five infested sites spanning both riparian and inland vegetation. Tubers were abundant in terms of density (~1000 per m2), although small in size and low in level of interconnectivity. M. unguis-cati also exhibits multiple stems per plant. Of all traits screened, the link between stand (stem density) and tuber density was the most significant and yielded a promising bivariate relationship for the purposes of estimation, prediction and management of what lies beneath the soil surface of a given M. unguis-cati infestation site. The study also suggests that new recruitment is primarily from seeds, not from vegetative propagation as previously thought. The results highlight the need for future biological-control efforts to focus on introducing specialist seed- and pod-feeding insects to reduce seed-output.

Response of an invasive liana to simulated herbivory: implications for its biological control

Pre-release evaluation of the efficacy of biological control agents is often not possible in the case of many invasive species targeted for biocontrol. In such circumstances simulating herbivory could yield significant insights into plant response to damage, thereby improving the efficiency of agent prioritisation, increasing the chances of regulating the performance of invasive plants through herbivory and minimising potential risks posed by release of multiple herbivores. We adopted this approach to understand the weaknesses herbivores could exploit, to manage the invasive liana, Macfadyena unguis-cati. We simulated herbivory by damaging the leaves, stem, root and tuber of the plant, in isolation and in combination. We also applied these treatments at multiple frequencies. Plant response in terms of biomass allocation showed that at least two severe defoliation treatments were required to diminish this liana's climbing habit and reduce its allocation to belowground tuber reserves. Belowground damage appears to have negligible effect on the plant's biomass production and tuber damage appears to trigger a compensatory response. Plant response to combinations of different types of damage did not differ significantly to that from leaf damage. This suggests that specialist herbivores in the leaf-feeding guild capable of removing over 50% of the leaf tissue may be desirable in the biological control of this invasive species.

Two varieties of the invasive liana, cat’s claw creeper, Macfadyena unguis-cati (Bignoniaceae) in Queensland, Australia

The invasive liana cat’s claw creeper, Macfadyena unguis-cati, native to tropical Central and South America, is a major environmental weed in Queensland and New South Wales (NSW). Two morphologically distinct cat’s claw creeper varieties occur in Australia, a ‘short-pod’ variety that is widespread through Queensland and NSW and a ‘long-pod’ variety restricted to a few sites in southeast Queensland. In this study we report the differences in the above-ground morphological, phenological and reproductive traits between the two varieties. The ‘long-pod’ variety has significantly larger leaves, larger pods, and larger number of seeds per pod than the ‘short-pod’ variety. The ‘short-pod’ variety has a slightly wider pods, and thicker leaves than the ‘long-pod’ variety. Both varieties have a yellow trumpet shaped flower, but the flower of the ‘long-pod’ variety has a deeper hue of yellow than the ‘short-pod’ flower. The fruits of the ‘short-pod’ variety mature in late summer to early autumn while the fruits of ‘long-pod’ variety mature in late winter to early spring. The more widespread nature of the ‘short-pod’ variety could potentially be due to a preference for this variety as an ornamental plant, due to its more presentable foliage characteristics and shorter pods, in contrast to the ‘long-pod’ variety.

Els paradigmes del mestre i del deixeble en Ramon Llull. Imatges i símbols de la pedagogia lul.liana. 'Los paradigmas del maestro y del discípulo en Ramon Llull. Imágenes y símbolos de la pedagogía luliana'.

Indagación del simbolismo psicoprofundo, en su dimensión pedagógica, de unas imágenes y figuras presentes en el pasaje del encuentro entre el maestro y el discípulo. Unas obras determinadas de Ramón Llull: 'Llibre de l'orde de cavalleria', 'Blanquerna', 'El desconhort', 'Félix o llibre de les meravelles del món'. Se parte de un análisis comparativo centrado en el estudio de los paralelismos que las imagenes y figuras del prólogo del 'Llibre de l'orde de cavalleria' guarda con determinadas figuras de los cuentos populares. A partir de aquí se aborda el estudio de dos personajes representativos de la obra luliana: Blanquerna y Félix; esbozando los perfiles del maestro y el discípulo. Posteriormente se realiza un estudio psicológico de Ramón Llull desde sus mismos símbolos y, fundamentalmente, desde sus imágenes del caballero y del viejo sabio. Los paradigmas del maestro y del discípulo que nos presenta Ramón Llull no son el resultado de una formulación teórica, sino, al contrario, esquejes del propio ser personal.

STEM ANATOMY and DEVELOPMENT of SUCCESSIVE CAMBIA IN THE NEOTROPICAL LIANA SECURIDACA RIVINIFOLIA (POLYGALACEAE)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nested liana-tree network in three distinct neotropical vegetation formations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variation in liana abundance and biomass along an elevational gradient in the tropical Atlantic Forest (Brazil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comportamento fenológico da liana Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae) em área de cerradão na Estação Ecológica de Assis, SP.

Brazilian cerrado is characterized by an evident seasonality with distinct dry and wet seasons. Pyrostegia venusta is a common vine found in different physiognomies of the Cerrado. The species may present characteristics that allow its adjustment to the seasonal cycles. The phenology of vegetative and reproductive events was studied for this species in 2004 and 2005. The objective was to verify which climatic factors determine the phenological patterns observed in the species. Flowering was inversely related to mean temperatures and to the length of the day, while fruiting was inversely related to the photoperiod and directly related to the mean wind velocity. Seed dispersal was directly related to wind speed. As a consequence, flowering occurred at the end of the rainy season, close to the winter, and was prolonged until the end of the dry season. Fruiting and fruit maturation occurred during the dry period, with the seeds being dispersed at the end of this period. The seed dispersal at the end of the dry season, common to other anemochoric species of cerrado, allows a rapid germination at the beginning of the wet season, favoring the species propagation in this environment.

Theoretical approaches to liana management: a search for a less harmful method

Lianas can change forest dynamics, slowing down forest regeneration after a perturbation. In these cases, it may be necessary to manage these woody climbers. Our aim was to simulate two management strategies: (1) focusing on abundant liana species and (2) focusing on the largest lianas, and contrast them with the random removal of lianas. We applied mathematical simulations for liana removal in three different vegetation types in southeastern Brazil: a Rainforest, a Seasonal Tropical Forest, and a Woodland Savanna. Using these samples, we performed simulations based on two liana removal procedures and compared them with random removal. We also used regression analysis with quasi-Poisson distribution to test whether larger lianas were aggressive, i.e., if they climbed into many trees. The procedure of cutting larger lianas was as effective as cutting them randomly and proved not to be a good method for liana management. Moreover, most of the lianas climbed into one or two trees, i.e., were not aggressive. Cutting the most abundant lianas proved to be a more effective method than cutting lianas randomly. This method could maintain liana richness and presumably should accelerate forest regeneration.

Variation in liana abundance and biomass along an elevational gradient in the tropical Atlantic Forest (Brazil)

Lianas play a key role in forest structure, species diversity, as well as functional aspects of tropical forests. Although the study of lianas in the tropics has increased dramatically in recent years, basic information on liana communities for the Brazilian Atlantic Forest is still scarce. To understand general patterns of liana abundance and biomass along an elevational gradient (0-1,100 m asl) of coastal Atlantic Forest, we carried out a standard census for lianas a parts per thousand yen1 cm in five 1-ha plots distributed across different forest sites. On average, we found a twofold variation in liana abundance and biomass between lowland and other forest types. Large lianas (a parts per thousand yen10 cm) accounted for 26-35% of total liana biomass at lower elevations, but they were not recorded in montane forests. Although the abundance of lianas displayed strong spatial structure at short distances, the present local forest structure played a minor role structuring liana communities at the scale of 0.01 ha. Compared to similar moist and wet Neotropical forests, lianas are slightly less abundant in the Atlantic Forest, but the total biomass is similar. Our study highlights two important points: (1) despite some studies have shown the importance of small-scale canopy disturbance and support availability, the spatial scale of the relationships between lianas and forest structure can vary greatly among tropical forests; (2) our results add to the evidence that past canopy disturbance levels and minimum temperature variation exert influence on the structure of liana communities in tropical moist forests, particularly along short and steep elevational gradients.