Clerodendrum chinense (Chinese glory bower).

C. chinense is a highly invasive weed in tropical and subtropical ecosystems. This species has the capacity to move into a habitat and reproduce aggressively by root suckers. C. chinense is classified as a "major weed" in Hawaii, Fiji, Western Samoa, and America Samoa (PIER, 2012) where it grows commonly along roadsides and as an ornamental shrub in gardens. This species rapidly invades pastures and plantations wherever it is planted forming dense thickets that exclude other species (Space and Flynn, 2002; Motooka et al., 2003). In the West Indies, C. chinense is included in lists of invasive species in Cuba, Puerto Rico, and US Virgin Islands (Acevedo-Rodríguez and Strong, 2012; González et al., 2012) and is classified as a widespread exotic plant in the Lesser Antilles (including Antigua, Barbados, Dominica, Grenada, Guadeloupe, Martinique, Montserrat, St. Lucia, and St. Vincent; Broome et al., 2007).

Extensive clonal propagation and resprouting drive the regeneration of a Brazilian dry forest

Woody plant resprouting has received considerable attention in the last two decades as human disturbances continue to encroach on terrestrial ecosystems globally. We examined the regeneration mechanisms of a Caatinga dry forest in the context of slash-and-burn agriculture and resprouting ability of the local flora. We excavated two old fields (from 32) experiencing early forest regeneration dominated by the tree Pityrocarpa moniliformis (Fabaceae) to map clonal propagation and, in parallel, submitted 260 seedlings from 13 woody plant species to experimental clipping. What seemed to be ‘seedlings’ popping up around P. moniliformis stumps and remaining adults actually were condensed sets of root suckers connected via complex networks of long, ramified shallow horizontal roots without taproots. We mapped respectively 39 and 783 connected root suckers, which summed 96 m and 910 m in root length. Regarding the seedlings, 33% resprouted across nine species with resprouting rates varying between 5–100%. Seedling height before clipping positively influenced resprouting vigour. Our preliminary results suggest that the Caatinga dry forest supports a relatively high proportion of resprouting species, some of them able to clonally propagate and playing an ecosystem-level role by responding to early forest regeneration and high abundance/biomass across both regenerating and old-growth forests.

Olea europaea subsp. cuspidata (wild olive).

A medium-sized, evergreen tree which is indigenous in western Himalaya in the Indo-Pakistan sub-continent, ascending to 2000 m. It is a slow growing, shade, drought and fire-tolerant tree, often lopped for fodder. It coppices well, produces root suckers and may also be grown from seed and cuttings. The stem is generally crooked. The wood is used for agricultural implements, turnery articles, tool handles and as a fuel. The root-stock of this species is sometimes used for grafting the European olive, O. europaea subsp. europaea. It is a useful tree for soil conservation and erosion control in its natural habitat.

A simplified method for application of natural regeneration in black locust (Robinia pseudoacacia L.) stands in Hungary

Black locust (Robinia pseudoacacia L.) is one of the most important forest tree species in Hungary, covering approximately 24% of the forest land and providing 25% of the annual timber supply. One third of these black locust stands are high forests (planted with seedlings) and the remaining stands are coppices. An auxiliary table was developed for planning the black locust natural regeneration in order to determine the sprouting criteria based on stand volume at the final cutting age. Twenty forest subcompartments were selected for investigating the possibility of black locust regeneration by root suckers. The basic yield and stand structure factors were determined using the numerical yield table for black locust stands. The results show that the regeneration of black locust stands from root suckers can be recommended on good and medium quality sites without a decrease in yield or stem quality. Black locust stands of good and medium quality (yield classes I, II, III and IV) may be regenerated from suckers in general until their growing stock attains and if their health is adequate. The simplicity of the practice-oriented auxiliary table based on the black locust yield table may further the development of management and wood utilization of the species.

Standardization of nitrogen application for potted Chrysanthemum morifolium cv. kikiobiory

The present investigation was carried out to standardize nitrogen application for standard potted Chrysanthemum morifolium cv. Kikiobiory at Department of Floriculture and Landscaping, PAU, Ludhiana during the year 2015-16. Six treatments of nitrogen viz. 0, 100, 200, 300, 400 and 500 mg/pot were applied twice in the last week of September and October. The results of the study revealed that nitrogen application had significant effect on all the vegetative and floral parameters. The largest flower size (17.69 cm) was obtained with the nitrogen application of 400 mg/pot which was at par with 500 mg/ pot (17.67 cm). Application of nitrogen at 500 mg/pot recorded the highest plant height (75.47 cm), number of leaves per plant 75 days after planting (30.92), number of root suckers per plant (11.47) and delayed flower bud appearance (93.78 days), color break stage (122.59 days) and also shown flower quality deterioration by reducing the flowering duration (5.84 days) as compared to the other treatments. Therefore, it was concluded that 300 mg of nitrogen per pot applied twice was the standard dose for quality flower pot production in Chrysanthemum morifolium cv. Kikiobiory.

Breynia disticha (snowbush).

B. disticha is considered as an invasive shrub to small tree in USA (Florida and Hawaii), Guinea, The British Indian Ocean Territory, Niue and Cuba (Oviedo Prieto et al., 2012; Swearingen and Bargeron, 2016; PIER, 2017). The species invades areas close to where cultivated by root suckers (PIER, 2017). In Cuba it is considered as a transformer species, without further details (Oviedo Prieto et al., 2012). It is regarded as an invasive species in Florida-USA by Swearingen and Bargeron (2016), although it is not in the Florida Exotic Pest Plant Council's list of invasive plant species (Florida Exotic Pest Plant Council, 2017). At Dave's Garden (2017) it is considered by the community as an invasive species in southern Florida, having the ability to spread quickly from roots in damp soils. It is not considered as an invasive species for Florida by Gilman (2014). In Hawaii-USA it has escaped from cultivation and is spreading vegetatively around abandoned homesites in Hawaii (PIER, 2017). In Guinea, the green-form of B. disticha is considered as an invasive species along the roadsides, in secondary thickets over many hectares, at the edge of a mangrove and in woodlands (Cheek et al., 2013). As its been found in areas with no evidence of former cultivation, apparently spreading through seeds. It has been collected in fruit at one of the sites. No details about its invasiveness are given for the British Ocean Territory and Niue.

Alocasia cucullata (Chinese taro).

Alocasia cucullata is a clumping evergreen herbaceous plant that is grown as a food plant and as an ornamental in areas within and outside its native distribution range of tropical and temperate Asia. This species spreads by seed and vegetatively by root suckers, rhizomes and corm fragments. It is listed as invasive in Cuba, Costa Rica, Hawaii, Fiji, the Cook Islands, Micronesia and French Polynesia. It is also listed in the Global Compendium of Weeds. A. cucullata is considered an invasive species with the potential to colonize and become naturalized in the understorey of rainforests and moist areas along streams and riverbanks.

Clerodendrum paniculatum (pagoda flower).

Clerodendrum paniculatum is a shrub which is widely cultivated as an ornamental for its spectacularly showy inflorescences. This species often establishes as a garden escapee. Its ability to produce root suckers allows the species to easily colonize new areas. Once established, it can form clonal stands of several plants. C. paniculatum is included in the Global Compendium of Weeds and listed as invasive in Singapore, Cuba, Hawaii, French Polynesia, Micronesia, Fiji, Palau, New Guinea, the Solomon Islands and Western Samoa.

Accumulation of heavy metals by silverberry softwood shoots cultivated in urban environments

Vehicle emissions make up to 50% of total pollutant emissions in Russia. The main roadside pollutants are heavy metals, petrol oil, lubricants and different readily soluble salts. Silverberry or Elaeagnus argentea Pursh is a deciduous shrub with height up to 4 meters, spreading crown, silver leaves and fruits. It originates from North America and is known since 1813. Its specific features are rather slow growth and ability to grow due to abundant root system. It reproduces itself by seeds, shoots and root suckers. It tolerates transplantation and cutting well. Due to such features as decorative effect, frost resistance, unpretentiousness to soil, resistance to drought, smoke and gases, some researchers recommend to use Elaeagnus argentea Pursh in urban greening. This kind is quite common in single or multiple plantings in Moscow such as green hedges in parks and along roads. Elaeagnus argentea Pursh is not only ornamental but also a medicinal plant.

Ecology of Natural Regeneration of Tropical Dry Forests of Africa and Its Implications for Their Sustainable Man

Recovery of African dry forests and woodlands is through either sexual or vegetative means. A sufficient number of regeneration pool (root suckers, sprouts, and seedlings) tend to occur in the herbaceous layer of the African dry forests. However, the prevailing environmental conditions such as fires and competition for nutrients and light influence the number of surviving individuals to enter the next size class. Developing restoration strategy for the African savannas requires the knowledge of regeneration mechanisms and dynamics of these woodlands which will be helpful in their management.