Invasive species

The last two decades have seen an upsurge in research into the potential synergies between invasive species and climate change, with evidence emerging of increased invader success under climate change. All stages along the naturalization-invasion continuum are likely to be affected, from the introduction and establishment of alien species to their spread and transition to serious invaders. A key question is whether alien plants will have a relative advantage under climate change conditions.

Disturbances are a primary facilitator of the growth and spread of invasive species. However, the effects of large-scale disturbances, such as hurricanes and tropical storms, on the broad geographic patterns of invasive species growth and spread have not been investigated. We used historical aerial imagery to determine the growth rate of invasive Phragmites australis patches in wetlands along the Atlantic and Gulf Coasts of the United States. These were relatively undisturbed wetlands where P. australis had room for unrestricted growth. Over the past several decades, invasive P.

In tropical forests, natural disturbance creates opportunities for species to claim previously utilized space and resources and is considered an important mechanism in the maintenance of species diversity. However, ecologists have long recognized that disturbance also promotes exotic plant invasions. Cyclones cause extensive defoliation, loss of major branches and multiple tree falls, resulting in a significantly more open canopy and increased light and heat levels in the understorey.

In September 2003, Hurricane Isabel caused unexpectedly high levels of wind damage to an 80-to 100-year-old forest in the Piedmont of Maryland. The storm had decreased in intensity from landfall by the time it reached the study site—sustained winds were moderate and maximum gusts recorded in the area were only 62.7 mph (28.1 m?s-1). Midsized gaps (up to 1 ha) were created in forest that historically had only small or single-tree gaps. Isabel created the opportunity to determine whether natural disturbance facilitates the spread of exotic invasive plant species.

Agriculture and food production offer stable livelihood options to rural communities throughout Asia and the Pacific region. Even as the effects of globalization spread in the region, farm production – most often at the smallholder level – continues to be a family enterprise. A fair share of farmers in the region engages in subsistence farming and poverty is a common occurrence among them. Farm enterprises are mostly managed by family members and family labour is a critical asset and often the only reliable investment.

The importance of vector and pest control in disasters and emergencies

Invasive alien plants and animals are known for their disruption of ecosystems and threat to biodiversity. This book highlights their major impact on human health. This includes not only direct effects through contact with the species via bites, wounds and disease, but also indirect effects caused by changes induced in ecosystems by invasive species, such as more water hyacinth increasing mosquito levels and thereby the potential for malaria.

With the wide acceptance of forest?protection policies in the developing world comes a requirement for clear demonstrations of how deforestation may erode human well?being and economies. For centuries, it has been believed that forests provide protection against flooding. However, such claims have given rise to a heated polemic, and broad?scale quantitative evidence of the possible role of forests in flood protection has not been forthcoming.