Bulan Carol A, Barrett Gary W
Ecology. 1971 Jul;52(4):597-605. doi: 10.2307/1934147.
The effects of two acute stresses, mowing and burning, on the arthropod component of an experimental grassland ecosystem were investigated. Oats (Avena sativa L.) were planted in two comparable and adjacent 1-acre areas. Midway in the growing season (July), one area was mowed and the other areas was both mowed and burned. Density and biomass were used to measure the effects of both stresses on the total arthropod community, while species diversity and equitability were used to analyze the species composition and apportionment of the Coleoptera. Effects of mowing on arthropod density and biomass appeared to be relatively brief (2 weeks) as compared with those of burning (3 months). This difference was attributed to a shift from live primary producer energy to detritus in the mowed area, as compared to the almost complete destruction of the energy source in the burned area. Coleoptera species/area diversity was significantly lower (P < 0.01) in the burned area. This was attributed to a greater energy supply and a larger number of ecological niches in the unburned grid. Margalef's species diversity, D = (S-1)/1nN, for the total Coleoptera community was significantly reduced (P < 0.05) in response to the fire. When analyzed by trophic levels on a long-term basis, herbivorous Coleoptera species diversity was significantly reduced (P < 0.01), whereas that of the carnivorous Coleoptera was not measurably affected. Herbivorous Coleoptera equitability values, in response to mowing, exhibited a brief increase before returning to the premow level. In response to burning, however, herbivorous Coleoptera equitability values remained higher than those in the unburned area, indicating a longterm limitation of resources. Carnivore equitability values did not exhibit a long-term increase in response to the fire stress. Coleoptera responses to fire revealed that biomass, species/area diversity, and primary consumer species diversity and equitability were the most sensitive indicators for evaluating the effects of an acute environmental stress such as fire. Coleoptera responses appeared to be representative of the total arthropod community.
研究了刈割和火烧这两种急性胁迫对实验性草地生态系统节肢动物组成部分的影响。在两个相邻且可比的1英亩区域种植燕麦（ Avena sativa L.）。在生长季节中期（7月），一个区域进行刈割，另一个区域既进行刈割又进行火烧。密度和生物量用于衡量两种胁迫对整个节肢动物群落的影响，而物种多样性和均匀度用于分析鞘翅目昆虫的物种组成和分配情况。与火烧（3个月）相比，刈割对节肢动物密度和生物量的影响似乎相对短暂（2周）。这种差异归因于与火烧区域几乎完全破坏能源相比，刈割区域从活的初级生产者能量向碎屑的转变。火烧区域的鞘翅目物种/面积多样性显著更低（P < 0.01）。这归因于未火烧网格中有更多的能量供应和更多的生态位。由于火灾，整个鞘翅目群落的马加利夫物种多样性指数D = (S - 1)/lnN显著降低（P < 0.05）。从长期营养级水平分析，食草性鞘翅目物种多样性显著降低（P < 0.01），而肉食性鞘翅目物种多样性未受明显影响。食草性鞘翅目的均匀度值在刈割后先短暂增加，然后恢复到刈割前水平。然而，在火烧后，食草性鞘翅目的均匀度值仍高于未火烧区域，表明存在长期的资源限制。肉食性鞘翅目的均匀度值在火灾胁迫下未出现长期增加。鞘翅目对火灾的反应表明，生物量、物种/面积多样性以及初级消费者物种多样性和均匀度是评估火灾等急性环境胁迫影响的最敏感指标。鞘翅目的反应似乎代表了整个节肢动物群落。
