The Imperata grasslands of tropical Asia: area, distribution, and typology

Abstract

The rehabilitation or intensified use of lmperata grasslands will require a much better understanding of their area, distribution, and characteristics. We generated estimates of the area of Imperata grasslands in tropical Asia, and suggested a typology of Imperata grasslands that may be useful to define the pathways toward appropriate land use intensification. We conclude that the area of lmperata grasslands in Asia is about 35 million ha. This is about 4% of the total land area. The countries with the largest area of Imperata grasslands are Indonesia (8.5 million ha) and India (8.0 million ha). Those with the largest proportion of their surface area covered with Imperata are Sri Lanka (23%), the Philippines (17%), and Vietnam (9%). Laos, Thailand, Myanmar, and Bangladesh evidently all have similar proportions of their land area infested with lmperata (about 3 to 4%). Malaysia (< 1%), Cambodia (1%), and the southern part of China (2%) have but a minor proportion of their total land area in lmperata. The species was found widely distributed on the full range of soil orders. It occupied both fertile (e.g. some of the Inceptisols and Andisols) and infertile soils (Ultisols and Oxisols) across a wide range of climates and elevations, lmperata lands fall into four mapping scale-related categories: Megagrasslands, macro-grasslands, meso-grasslands, and micro-grasslands. The mega-grasslands are often referred to as 'sheet lmperata'. They are the large contiguous areas of Imperata that would appear on small-scale maps of say 1:1,000,000. We propose that this basic typology be supplemented with a number of additional components that have a key influence on intensification pathways: land quality, market access, and the source of power for tillage. The typology was applied in a case study of Indonesian villages in the vicinity of lmperata grasslands. We propose an international initiative to map and derive a more complete and uniform picture of the area of the Imperata grasslands. This should include selected studies to understand conditions at the local level. These are critical to build the appreciation of change agents for the indigenous systems of resource exploitation, and how they relate to local needs, values, and constraints.

Characteristics of speargrass (Imperata cylindrica) dominated fields in West Africa: crops, soil properties, farmer perceptions and management strategies

“…Percent sand was higher in soils from the CDS than those from the SGS rvhile % silt and o/o clay followed the opposite trend. These results agree with previous research that has shown that speargrass occurs on soils with a lvide range of soil properties (Garrity et al, 1997;Santoso et al, 1991: Chikoye et al, 1999. In soils with inherent low soil fertility such as those encountered in this study, poor crop growth facilitates the growth and dominance of speargrass (Santoso et al, 1991).…”

“…Spcargrass llntperata cylinclrica (L.) Raueschel] is one of the most dominant, competiti.re, and difficult weeds to coutrol in the humid and sub-humid tropics of Asia, Wcst Africa, and Latin America (Garrity et al, 1997). ln Wcst Africa.…”

Biological invasions and biocultural diversity: linking ecological and cultural systems

“…I. cylindrica is used ritually by the Balinese (Rifai & Widjaja 1979) and the Karen of northern Thailand (Potter 1997) and is employed throughout the region to thatch and adorn the roofs of bamboo huts. Alang-alang fields are decreasing throughout Indonesia; on Java the coverage has decreased from over 30% at the beginning of the 20th century to current levels of less than 2% (Garrity et al 1997); in Eastern Indonesia the increasing scarcity of alang-alang is forcing families to purchase roofing material for the first time (Potter et al 2000;J. Pfeiffer, personal observation 2006).…”

Struktur Dan Komposisi Gulma Pada Tanaman Lada Yang Berperan Untuk Mengonservasi Serangga Parasitoid

“…cylindrica merupakan tumbuhan rumput tahunan dan dianggap sebagai gulma di lahan pertanian, tumbuh di daerah dengan curah hujan tinggi (Garrity et al 1996). Gulma tersebut umumnya tumbuh di areal tanaman tahunan.…”