3、osysteminNorthChinaplain.First, inthecomponentofthe1930’sagroecosystem,peasant’s animalhusbandrydecreasedaspopulationpressurebecame serious;Second,traditionalagroecosystemisusuallyat N-Limitationandwater-limitation.Third,the amount of human and animalenergyinputchangedac
4、cordingtoland scale.Households ownmorelandhavemoreanimals,input,but smaller human’s.inputandhouseholdsownless land have more human’s power butsmallerdraughtanimal’s,but difference of energy inputbetweentwogroupsisnotobvious.The change of productionprocess is not like the
5、 theory of ”AgriculturalInvolution”whichiswidelyusedby some scholars,instead ofthat,productionchange is mostly a ecological change,thepopulationpressuremadepeasantusingmore human labor andlessanimalpower.【正文】一、问题的提出 从人与生态环境关系角度研究社会历史过程,是一个新的热点,只是实证研究较少。进一步深入研究的关键在于个案材料的