Biosphere 2 engineering design

Dempster, William F.

doi:10.1016/s0925-8574(98)00090-1

Cited by 36 publications

(19 citation statements)

References 4 publications

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“…The size of the trees had not changed significantly by the end of the experiment, averaging 11.4 ± 1.3 m in height and 95.2 ± 11.2 mm in basal diameter. Further details on climate control and the structure of the IFM can be found elsewhere (Lin et al ., 1998; Dempster, 1999; Zabel et al ., 1999; Griffin et al ., 2002a,b; Murthy et al ., 2003; Engel et al ., 2004; Barron‐Gafford et al ., 2005; Murthy et al ., 2005). Soil depth averaged 1 m and approximated a rich agricultural loam (Torbert & Johnson, 2001) with microflora characteristic of agricultural and natural soils (Lipson et al ., 2006).…”

Section: Methodsmentioning

confidence: 99%

Leaf‐ and stand‐level responses of a forested mesocosm to independent manipulations of temperature and vapor pressure deficit

2007

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Summary• Alterations in temperature (T) and vapor pressure deficit (VPD) strongly influence gas exchange, but because VPD is highly influenced by T, the effects of these two factors are difficult to separate.• Here, the concomitant effects of T and VPD on CO 2 uptake, stomatal conductance, and transpiration at leaf-and canopy-levels were examined for a stand of trees (Populus deltoides) enclosed within large mesocosms. T and VPD were independently altered to yield a factorial combination of treatments of low (24°C) or high (30°C) T and low (0.75) or high (1.75 kPa) VPD. Traditional leaf-level gas exchange measurements were compared with whole-canopy exchange to verify typical scaling methods.• Elevated T resulted in an average 40% and 14% increase in midday leaf-level and canopy-level net CO 2 uptake, respectively. Other physiological responses to elevated T and VPD were similar at both scales, but the magnitude of change was usually less pronounced at the canopy-level.• Surprisingly, only minimal interactions between T and VPD were found to influence responses of CO 2 uptake and stomatal conductance at either level.

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Section: Methodsmentioning

confidence: 99%

Leaf‐ and stand‐level responses of a forested mesocosm to independent manipulations of temperature and vapor pressure deficit

2007

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“…Details of the Biosphere 2 environmental control system are described elsewhere (Lin et al . 1998; Dempster 1999; Zabel et al . 1999; Griffin et al .…”

Section: Methodsmentioning

confidence: 99%

The relative impacts of daytime and night‐time warming on photosynthetic capacity inPopulus deltoides

Turnbull

Murthy

Griffin

2002

Plant Cell & Environment

246

171

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ABSTRACT∞ C treatment. These increases in photosynthetic capacity were associated with strong increases in the maximum carboxylation rate of rubisco ( V cmax ) and ribulose-1,5-bisphosphate (RuBP) regeneration capacity mediated by maximum electron transport rate ( J max ). Leaf soluble sugar and starch concentration, measured at sunrise, declined significantly as nocturnal temperature increased. The nocturnal temperature manipulation resulted in a significant inverse relationship between A max and pre-dawn leaf carbohydrate status. Independent measurements of the temperature response of photosynthesis indicated that the optimum temperature ( T opt ) acclimated fully to the 6 ∞ ∞ ∞ ∞ C range of temperature imposed in the daytime warming. Our findings are consistent with the hypothesis that elevated night-time temperature increases photosynthetic capacity during the following light period through a respiratory-driven reduction in leaf carbohydrate concentration. These responses indicate that predicted increases in night-time minimum temperatures may have a significant influence on net plant carbon uptake.

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“…We collected foliar material and measured the physiological properties of 149 species in two tropical forest sites on Hawaii island in January and April of 2009 and ten species in the tropical rainforest biome and the display center of B2L (Dempster 1999) in October 2004. We emphasized collecting data from many species versus repeating measurements on individual species because much of the variability in leaf nutrient concentrations can be explained by species variability (Townsend et al 2007).…”

Section: Study Sitesmentioning

confidence: 99%

Predicting tropical plant physiology from leaf and canopy spectroscopy

2010

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A broad regional understanding of tropical forest leaf photosynthesis has long been a goal for tropical forest ecologists, but it has remained elusive due to difficult canopy access and high species diversity. Here we develop an empirical model to predict sunlit, light-saturated, tropical leaf photosynthesis using leaf and simulated canopy spectra. To develop this model, we used partial least squares (PLS) analysis on three tropical forest datasets (159 species), two in Hawaii and one at the biosphere 2 laboratory (B2L). For each species, we measured light-saturated photosynthesis (A), light and CO(2) saturated photosynthesis (A(max)), respiration (R), leaf transmittance and reflectance spectra (400-2,500 nm), leaf nitrogen, chlorophyll a and b, carotenoids, and leaf mass per area (LMA). The model best predicted A [r(2) = 0.74, root mean square error (RMSE) = 2.9 μmol m(-2) s(-1))] followed by R (r(2) = 0.48), and A(max) (r(2) = 0.47). We combined leaf reflectance and transmittance with a canopy radiative transfer model to simulate top-of-canopy reflectance and found that canopy spectra are a better predictor of A (RMSE = 2.5 ± 0.07 μmol m(-2) s(-1)) than are leaf spectra. The results indicate the potential for this technique to be used with high-fidelity imaging spectrometers to remotely sense tropical forest canopy photosynthesis.

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Biosphere 2 engineering design

Cited by 36 publications

References 4 publications

Leaf‐ and stand‐level responses of a forested mesocosm to independent manipulations of temperature and vapor pressure deficit

Leaf‐ and stand‐level responses of a forested mesocosm to independent manipulations of temperature and vapor pressure deficit

The relative impacts of daytime and night‐time warming on photosynthetic capacity inPopulus deltoides

Predicting tropical plant physiology from leaf and canopy spectroscopy

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