@article {KNZ00670,
	title = {Aspects of methane flow from sediment through emergent cattail (Typha latifolia) plants},
	journal = {New Phytologist},
	volume = {139},
	year = {1998},
	pages = {495 -503},
	abstract = {We measured the flow of methane in Typha latifolia L. (cattail)-dominated wetlands from microbial production in anoxic sediment into, through, and out of emergent T. latifolia shoots (i.e. plant transport). The purpose was to identify key environmental and plant factors that might affect rates of methane efflux from wetlands to the Earth{\textquoteright}s atmosphere. Methane accumulated in leafy T. latifolia shoots overnight, reaching concentrations up to 10000 μl l-1 (vs. atmospheric concentrations <4 μl l-1), suggesting that lower stomatal conductance at night limits methane efflux from the plant into ambient air. Daytime light and (or) lower atmospheric humidity that induce convective gas flow through the plant coincided with (a) an increase in the rate of methane efflux from T. latifolia leaves to ambient air (from <0{\textperiodcentered}1 to >2{\textperiodcentered}0 μmol m-2 (leaf) s-1) and (b) a decrease in shoot methane concentration to <70 μl l-1. Very short fluctuation in stomatal conductance during the day did not affect the methane efflux rate unless, possibly, the rate of photosynthesis decreased. A strong relationship between the maximum daily rate of methane efflux and shoot methane concentration (measured before the onset of convective gas flow) suggests T. latifolia plants behave like a capacitor (filling with methane at night, emitting the stored methane during the day). Experimentally cutting leaves (to prevent pressurization) reduced plant capacitance for methane.},
	keywords = {LTER-KNZ},
	doi = {10.1046/j.1469-8137.1998.00210.x},
	author = {Yavitt, J.B. and Alan K. Knapp}
}
@article {KNZ00507,
	title = {Gas exchange characteristics of Typha latifolia L. from nine sites across North America},
	journal = {Aquatic Biology},
	volume = {49},
	year = {1995},
	pages = {203 -215},
	abstract = {Gas exchange characteristics were measured in the field for nine populations of Typha latifolia L. from Florida to Minnesota in North America. These populations spanned a substantial gradient in growing season length and environmental conditions. The purpose of this study was to assess geographic variability in stomatal conductance (gst) in T. latifolia populations, as well as to identify key environmental and plant factors that may affect gst and, potentially, trace gas emissions through stomata. Midday rates of net photosynthesis (A) and gst were measured under full sunlight conditions at each site, and more intensive measurements of diurnal and seasonal variability were made at selected sites. In general, A varied less than gst (1.5 vs. 3 fold) among sites with maximum A (27.4 μmol m-2 s-1) and gst (1076.7 mmol m-2 s-1) measured at the southern sites. We found that A and gst in T. latifolia increased significantly with increasing temperature and light level, and varied diurnally and seasonally. Moreover, stomata closed completely at night, in contrast to some other wetland plants. Both A and gst also increased significantly along the length of leaves from the base of plants to the upper canopy. Finally, although gst was quite variable, A did not appear to be limited by gst under typical field conditions. It was concluded that generalizations that stomata in wetland plants are relatively unresponsive to environmental factors are not consistent with field responses measured in T. latifolia. As a result, because gst may influence trace gas flux in this species, spatial and temporal variations in gst need to be considered when emissions are estimated.},
	keywords = {LTER-KNZ},
	doi = {10.1016/0304-3770(94)00433-M},
	author = {Alan K. Knapp and Yavitt, J.B.}
}
@article {KNZ00525,
	title = {Methane emissions to the atmosphere through emergent cattail (Typha latifolia L.) plants},
	journal = {Tellus},
	volume = {47},
	year = {1995},
	pages = {521 -534},
	keywords = {LTER-KNZ},
	doi = {10.3402/tellusb.v47i5.16065},
	author = {Yavitt, J.B. and Alan K. Knapp}
}
@proceedings {KNZ00524,
	title = {Wetlands may change tallgrass prairie from a sink to a source for atmospheric methane},
	year = {1995},
	pages = {137 -141},
	keywords = {LTER-KNZ, tallgrass prairie},
	url = {http://images.library.wisc.edu/EcoNatRes/EFacs/NAPC/NAPC14/reference/econatres.napc14.jyavitt.pdf},
	author = {Yavitt, J.B. and Alan K. Knapp},
	editor = {D.C. Hartnett}
}
@article {KNZ00368,
	title = {Evaluation of the closed-chamber method for estimating methane emissions from aquatic plants},
	journal = {Tellus},
	volume = {44B},
	year = {1992},
	pages = {63 -71},
	abstract = {<p>Closed flow chambers are commonly used to measure CH4 emissions from aquatic plants. We monitored environmental and plant physiological responses to closed chambers during measurements of CH4 emission from Typha latifolia (cattails) to evaluate potential errors in emission estimates. In 1990, two wetlands were studied: one in NE Kansas and one in central New York. Leaves and stems of Typha enclosed in gas-impermable, collapsible bags were exposed to rapid increases in chamber air temperature and, thus, tissue temperatures (up to 9oC above ambient) as well as rapid reductions in both CO2 partial pressure due to photosynthesis and the leaf-to-air water vapor pressure deficit due to transpiration. These rapid (\&lt; 5 min) environmental changes within chambers are known to affect stomatal aperture through which CH4 exists Typha leaves. Indeed, stomatal conductance (g) increased up to 42\% compared to control leaves after 19 min of enclosure in chambers, and chamber effects on interactions between irradiance and g were detected. The duration of enclosure also critically affected the CH4 gradient within chambers. Estimated CH4 emission from leaves in chambers sampled after 19 min (3 nmol m-2s-1) was 10-fold lower than estimates based on 30-s sampling periods (30 nmol m-2s-1) due to reduction in the leaf-to-air concentration gradient for CH4. Since closed chambers 1)induce alterations in g, 2)may result in rapid environmental changes, and 3)lead to almost instantaneous reductions in leaf-to-air concentration gradient for CH4 diffusion, we suggest that only very short enclosure times should be used when measuring CH4 emission from plants</p>},
	keywords = {LTER-KNZ},
	doi = {10.1034/j.1600-0889.1992.00006.x},
	author = {Alan K. Knapp and Yavitt, J.B.}
}
