ဘာရယ္ မဟုတ္ဘူး၊ သူငယ္ခ်င္း တစ္ေယာက္က ကိုယ္တိုင္ေရး Paper ေတြ ဘာေတြ ရွိရင္ တင္ပါလား ဆိုတာနဲ႔ တင္လိုက္တာပါ။ စာလည္းမၾကည့္ခ်င္လို႕။ ပထမ ႏွစ္တုန္းက မေရးတတ္ ေရးတတ္ နဲ႔ ပထမဆံုး ေရးထားတဲ႔ Assignment paper ပါ။ Publication ေတာ့ မဟုတ္ပါဘူး။
Prevention and Protection against Invasive Plant Species
By Pyi Soe Aung ( March 2011)
Introduction
Today, with heavy pressure of world population, it is crucial to maintain our life supporting systems. And conservation of biological diversity is the best way to achieve this, since it underpins a wide range of ecosystem services on which human societies have always depended for food and fresh water, health and recreation, and protection from natural disasters and so on (CBD, 2010). However, major alterations and loss of biodiversity are being experienced due to various reasons. One of the factors that contribute to loss of biodiversity is due to the introduction of invasive species, which could competitively suppress native species populations and alter habitats and ecosystems (Wetzel, 2005). Generally, the impacts of invasive species cost at least US$ 1.4 trillion annually – close to 5% GDP (Pimental et al., 2001; GISP, 2009) and they pose the biggest single threat to food security and human health. Also the Millennium Ecosystem Assessment had classified invasive species along with climate change as the two drivers damaging ecosystem function and human well-being that are the most difficult to reverse (Hassan et al., 2005; Smith et al., 2008). In this regard, it has become crucial important to prevent, protect or ameliorate the introduction of those alien species as well as their impacts towards ecosystem, habitats and species diversity. Early warning system, eradication and control as well as increased awareness and political leadership have become necessarily to be implemented. Also, global, regional and bilateral efforts including standards and guidelines, monitoring and assessment has come to be essential.
Since invasive plant species have a significant effect on the biological and human communities in which they appear, their appearance in both terrestrial and aquatic landscapes is associated with human activities and technology development that affect the environment. Various studies had highlighted that invasive plant species are increasing due to increased global movement of people, trade and transport of biological and agricultural commodities and unusual plant materials (Dekker, 2005). Therefore, it is necessary to analyze the means and routes by which invasive plant species are imported and introduced into new environments. Also various authors had highlighted that prevention or protection of these routes or pathways could be the best way to mitigate or ameliorate the harmful effects by these species (NISC, 2001; Clout and Williams, 2009). However, in reality, application of prevention and protection measures to these pathways or entries of invasive species had experienced various difficulties to achieve, particularly due to the absence of physical or ecological barriers to their movement (Clout and Williams, 2009). Therefore, it is necessary to consider effective management and control of these species other than protection alone, based on their nature and impact behavior to native species and environment.
Historical concerns on invasive species
Various authors and international organization had defined invasive species in different ways (Wittenberg et al., 2001; Inderjit et al., 2005; ISAC, 2006; NISC, 2008). Generally, an invasive species can generally be defined as “an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health (ISAC, 2006; NISC, 2008).” This definition relates to many types of invasive species such as plants, animals and microorganisms and focuses upon invasive species which are harmful, rather than focusing on non-native species, most of which are not harmful. However, in this case, as highlighted by Invasive Species Advisory Committee (ISAC), plant and animal species under domestication or cultivation and under human control are not invasive species (NISC, 2008). Also according to Global Invasive Species Program (GISP) founded by CABI, IUCN and TNC, invasive alien species are defined as non-native species that threaten, or have the potential to threaten, the environment, health or economic production
The history of plant invasion started since the time of early human immigrants, in which people not only brought language and culture with them, but also plants and animals that are familiar and useful to their cultures (Inderjit et al., 2005). Historically, concerns over the potential impacts of invasive species began in the late 18th century, notably John Bartram, an 18th century botanist, who noticed that some introduced plants negatively affected the environment and some were extremely difficult to control (Mack RN, 2003; Inderjit et al., 2005). For many decades, since the era of Charles Darwin (1809-1882) through Charles Elton (1900-1991), scientists had explicitly been studying to understand the process and dynamics of invasions and also trying to develop theories and approaches in order to predict and prevent invasion by harmful invasive plant species (Inderjit et al., 2005). And also various international conventions and organizations, such as CBD, IUCN, NISC, GISP, had also been trying to propose legal instruments and frameworks so as to support and underpin practical management and protection of these species. However, up to present days, invasive species are still invading and threatening to our biodiversity and human life supporting systems (Clout and Williams, 2009).
