Measurements of stomatal density and delta(13)C of limber pine (Pinus flexilis) needles (leaves) preserved in pack rat middens from the Great Basin reveal shifts in plant physiology and leaf morphology during the last 30,000 years. Sites were selected so as to offset glacial to Holocene climatic differences and thus to isolate the effects of changing atmospheric CO(2) levels. Stomatal density decreased approximately 17 percent and delta(13)C decreased approximately 1.5 per mil during deglaciation from 15,000 to 12,000 years ago, concomitant with a 30 percent increase in atmospheric CO(2). Water-use efficiency increased approximately 15 percent during deglaciation, if temperature and humidity were held constant and the proxy values for CO(2) and delta(13)C of past atmospheres are accurate. The delta(13)C variations may help constrain hypotheses about the redistribution of carbon between the atmosphere and biosphere during the last glacial-interglacial cycle.

Download full-text PDF

Source
http://dx.doi.org/10.1126/science.264.5156.239DOI Listing

Publication Analysis

Top Keywords

stomatal density
12
pinus flexilis
8
flexilis needles
8
glacial-interglacial cycle
8
atmospheric co2
8
trends stomatal
4
density 13c/12c
4
13c/12c ratios
4
ratios pinus
4
needles glacial-interglacial
4

Similar Publications

This study investigates the anatomical adaptations of leaves from two halophyte species, (Forsskal) Asch. and L., in response to pollutants from a cement factory and human activities.

View Article and Find Full Text PDF

Higher PEPC activity and vein density contribute to improve cotton leaf water use efficiency under water stress.

Plant Biol (Stuttg)

January 2025

Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Corps, Shihezi University, Shihezi, China.

Plants with the C photosynthetic pathway can withstand water stress better than plants with C metabolism. However, it is unclear whether C photosynthesis can be preliminarily activated in droughted cotton leaves, and if this contributes to increase in water use efficiency (WUE). An upland cotton (Gossypium hirsutum L.

View Article and Find Full Text PDF

From forests to farming: identification of photosynthetic limitations in breadfruit across diverse environments.

Tree Physiol

January 2025

Tropical Plant and Soil Sciences, College of Tropical Agriculture and Human Resources, University of Hawai'i at Mānoa, 3190 Maile Way, Honolulu, Hawai'i, USA.

Breadfruit (Artocarpus altilis) is a prolific tropical tree producing highly nutritious and voluminous carbohydrate-rich fruits. Already recognized as an underutilized crop, breadfruit could ameliorate food insecurity and protect against climate-related productivity shocks in undernourished equatorial regions. However, a lack of fundamental knowledge impedes widespread agricultural adoption, from modern agroforestry to plantation schemes.

View Article and Find Full Text PDF

Hydraulic conductivity and photosynthetic capacity of seedlings of genotypes.

Photosynthetica

January 2025

Plant Physiology Sector, State University of Norte Fluminense, Center for Sciences and Agricultural Technologies (CCTA), Avenida Alberto Lamego, 2000, 28015-620, Campos dos Goytacazes, RJ, Brazil.

The aim was to investigate the morphological, photosynthetic, and hydraulic physiological characteristics of different genotypes of under controlled cultivation conditions. Growth, conductance, and hydraulic conductivity of the root system of 16 genotypes were evaluated in Experiment 1 (November 2013). In Experiment 2 (December 2014), in addition to the previous characteristics, gas exchange, photochemical efficiency, leaf water potential, and leaf hydraulic conductivity were investigated in five genotypes.

View Article and Find Full Text PDF

This research investigates the interactive effects of elevated ozone (eO) and carbon dioxide (eCO) on stomatal morphology and leaf anatomical characteristics in two wheat cultivars with varying O sensitivities. Elevated O increased stomatal density and conductance, causing oxidative stress and cellular damage, particularly in the O-sensitive cultivar PBW-550 (PW), compared to HUW-55 (HW). Conversely, eCO reduced stomatal density and pore size, mitigating O-induced damage by limiting O influx.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!