Davidsonia

Davidsonia - A Journal of Botanical Garden Science

Editor, Iain Taylor writes about the destructive forces of nature in our wilderness parks and the responses of people to these inevitable changes.

Floral rewards for hummingbirds were studied in the arboretum of the Rio de Janeiro Botanical Garden. Twenty nine species were visited and between eight and nineteen species flowered each month, with a greater occurrence of species flowering during the austral winter, contrasting with the pattern of adjacent forest areas. Seventeen species (59%) were from America, mostly from South or South and Central America (thirteen species), and remaining species were from Central and/or North America. Most plant species fit into the hummingbird pollination syndrome and seven out of the twelve species from other continents fit into the perching-bird pollination syndrome, indicating that hummingbirds prefer flowers supposedly adapted to birds. Four species of hummingbirds were observed visiting flowers and two others were registered in the arboretum, representing less than half of the species registered in the forests of the region. The only resident species of the arboretum, Thalurania glaucopis Gmelim visited most species, exhibited territorial behaviour and was by far the most common species. Although the floral resources of the arboretum seemed to support the individuals of T. glaucopsis and could function as an additional resource for the hummingbirds from the adjacent forests, a higher diversity of both floral resources and micro-sites are recommended to make the arboretum and equivalent areas more hummingbird-friendly.

Aquilegia formosa, Castilleja hispida, C. miniata, C. rhexifolia, C. rupicola, Gilia aggregata, Lonicera ciliosa, Ribes lobbii, and Stachys cooleyae are the plant species in British Columbia which best fit the syndrome of hummingbird pollination. Impatiens capensis, I. noli-tangere, Lilium columbianum, Lonicera dioica, Monarda fistulosa, Ribes sanguineum, and Rubus spectabilis have mixed or transitional pollination strategies, being pollinated by both insects and hummingbirds. Examples of opportunistic nectar foraging by hummingbirds are recorded for several other species.

One line, “No rain, no crop, no feed, no faith, only wind” from Anne Marriott’s poem The Wind Our Enemy tells a vivid story of life on the Canadian Prairies during the dust bowl years. Uprooted trees portrayed the devastation caused by the wicked winds of the 2005 Hurricane Katrina when it hit New Orleans and the Gulf Coast of the United States. On December 15, 2006 a powerful wind made a shocking change in the appearance of the forest in Vancouver’s Stanley Park (UBC Faculty of Forestry, 2007). Wind indeed is enemy to plants, but in numberless ways it is also friend, and in the long term is essential in ecosystems.

Weather data recorded at UBC campus for the year 2006.

Instructions for authors wishing to submit manuscripts to Davidsonia for publication.