Japan: Alder, Beech & Willow endure rice paddy agriculture for at least two millennia.

Japan’s beech forests thrive in regions with cool summers and abundant
snow in winter, and form the dominant vegetation community in northern
and central Honshu, as well as on the higher mountainsides in southern
and western Japan. If global warming continues at the current pace,
the distribution of these beech forests will be pushed northward and
further up the mountainsides.

On some mountains in the warmer regions,
they may even be pushed right out into space! Ecosystems also respond
to changes in the physical environment imposed by human activities.
Throughout the world, new types of ecosystems came into being to adapt
to conditions generated by intensive agriculture. Here in Asia,
perhaps the greatest influence on natural systems over the past 10,000
years has been the development of irrigated rice culture. With the
exception of small paddies terraced into steep hillsides, rice paddies
are usually laid out along valley bottoms and low-lying alluvial
plains, regions which originally would have supported some type of
marshland community. These original communities were replaced by new
ones adapted to the paddy irrigation. Some of the species that
occupied the original wetland communities were unable to make the
transition to the new paddy environments. Others, however, were able
to adjust their behavior accordingly. Still others may have even found
the new conditions more favorable than the old. In Japan, various
species of dragonflies and frogs, for example, learned to thrive in
and around the paddies and irrigation ditches. Predators such as birds
and fish also thrived by feeding on these small animals. A

n entirely
new ecosystem, rich in species and interconnections, emerged, centered
on rice and finely tuned to coexist with the seasonal rhythms of paddy
agriculture. In western Japan, these changes started taking place
about 3,000 years ago. Analysis of fossil pollen shows that in the
narrow valley bottoms characteristic of the southern Kanto region,
wetland communities dominated by reeds, cattails, alders and willows
were replaced by rice paddies about 2,000 years ago. The rich,
biodiverse ecosystem we see today has thus been vibrating in tune with
rice paddy agriculture for at least two millennia. Truly interesting,
however, is what happens when a farmer abandons his rice paddies.
Nowadays, rice farming, especially in narrow valleys where the paddies
tend to be small and inefficient, is a marginal occupation. In many
cases, the sons and daughters have moved on to salaried jobs, leaving
only an elderly couple to work the paddies. Out in the north Chiba
Prefecture countryside where I live and work, there are some paddies
that were abandoned in the 1960s and 1970s. These have progressed
beyond the stage of reed and cattail marsh, and are completely
dominated by tall stands of Japanese alder. In some cases, the trees
are now so tall and dense that the crumbled remains of the aze dikes
are the only reminders of the valley’s former life as rice paddy
farmland. Japanese alder (hannoki = Alnus japonica) is a common local
species that thrives in habitats too wet for oaks or other typical
woodland trees.

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Comments (1)

Nina TaylorMay 11th, 2009 at 2:06 pm

try not to abandin your rice paddies. Fix your problem! YOUR SUPPOSE TO SOLVE YOUR PROBLEM NOT ABANDON IT!!!!!!!!!! Running away from your problems isn’t going to help! SMARTIES!

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