Long-term impact of prescribed burning on water use efficiency, biological nitrogen fixation, and tree growth of understory acacia species in a suburban forest ecosystem of subtropical Australia

The effect of repeated prescribed burning on long term growth of Pinus ponderosa in northern Arizona was examined. Fire treatments for hazard reduction were initiated in 1976, acid growth was evaluated in 1988 for fire rotations of 1, 2, 4, 6, 8, and 10 years. Dendroecological analysis shows that there were only small changes in tree growth (compared to controls) in the first few years after the initial fire treatment despite large fuel reductions and thinning, and that annual precipitation was positively correlated with growth. Moderate changes in growth relative to that of control trees were apparent after 1984. The 1-, 2-, 8-, and 10-year treatments had lower growth than controls after this date, while 4- and 6-year treatments had slightly higher growth. Although additional data are needed to determine long term growth effects in the longer fire rotations, a fire treatment interval of 4 to 6 years appears to provide adequate fuel reduction without reducing long term growth in Southwestern P. ponderosa forests.

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Biological Nitrogen Fixation in the Context of Global Change

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-12-12-0293-cr ◽

2013 ◽

Vol 26 (5) ◽

pp. 486-494 ◽

Cited By ~ 85

Author(s):

José Olivares ◽

Eulogio J. Bedmar ◽

Juan Sanjuán

Keyword(s):

Nitrogen Fixation ◽

Biological Nitrogen Fixation ◽

Food Production ◽

Agricultural Practices ◽

N Fertilization ◽

Agricultural Crops ◽

Nitrogen Fixing ◽

Sustainable Technologies ◽

Use Efficiency ◽

Biological Nitrogen

The intensive application of fertilizers during agricultural practices has led to an unprecedented perturbation of the nitrogen cycle, illustrated by the growing accumulation of nitrates in soils and waters and of nitrogen oxides in the atmosphere. Besides increasing use efficiency of current N fertilizers, priority should be given to value the process of biological nitrogen fixation (BNF) through more sustainable technologies that reduce the undesired effects of chemical N fertilization of agricultural crops. Wider legume adoption, supported by coordinated legume breeding and inoculation programs are approaches at hand. Also available are biofertilizers based on microbes that help to reduce the needs of N fertilization in important crops like cereals. Engineering the capacity to fix nitrogen in cereals, either by themselves or in symbiosis with nitrogen-fixing microbes, are attractive future options that, nevertheless, require more intensive and internationally coordinated research efforts. Although nitrogen-fixing plants may be less productive, at some point, agriculture must significantly reduce the use of warming (chemically synthesized) N and give priority to BNF if it is to sustain both food production and environmental health for a continuously growing human population.

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Nitrogen fixation and acetylene reduction in decaying conifer boles: effects of incubation time, aeration, and moisture content

Canadian Journal of Forest Research ◽

10.1139/x82-098 ◽

1982 ◽

Vol 12 (3) ◽

pp. 646-652 ◽

Cited By ~ 49

Author(s):

Warwick B. Silvester ◽

Phillip Sollins ◽

Thomas Verhoeven ◽

Steven P. Cline

Keyword(s):

Nitrogen Fixation ◽

Moisture Content ◽

Forest Ecosystem ◽

Acetylene Reduction ◽

Preliminary Survey ◽

Anaerobic Conditions ◽

Free Living ◽

Living Organisms ◽

Low Activity

Free-living microaerophiles fixed 15N2 and reduced acetylene in fallen tree boles at two old-growth Pseudotsugamenziesii stands in western Oregon. Acetylene reduction was most rapid under an atmosphere of 2–10% O2, whereas under prolonged anaerobic conditions it was at or below detection limits. Acetylene reduction rates increased up to fourfold during long-term incubations in acetylene (> 12 h). Ratios of acetylene reduction to N2 fixation frequently exceeded 6.0 during such long-term incubations but averaged 3.5 when samples were incubated < 7 h; consequently, long-term incubation of low-activity material in acetylene should be avoided. A preliminary survey indicated that N2 fixation by free-living organisms in fallen boles was less than other potential N inputs to fallen boles and to the forest ecosystem.

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Long-term variation of tree growth and intrinsic water-use efficiency in Schrenk spruce with increasing CO2 concentration and climate warming in the western Tianshan Mountains, China

Acta Physiologiae Plantarum ◽

10.1007/s11738-015-1903-y ◽

2015 ◽

Vol 37 (8) ◽

Cited By ~ 11

Author(s):

Guoju Wu ◽

Xiaohong Liu ◽

Tuo Chen ◽

Guobao Xu ◽

Wenzhi Wang ◽

...

Keyword(s):

Water Use ◽

Climate Warming ◽

Tree Growth ◽

Co2 Concentration ◽

Tianshan Mountains ◽

Western Tianshan ◽

Intrinsic Water Use Efficiency ◽

Term Variation ◽

Use Efficiency

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Long-term thinning effects on tree growth, drought response and water use efficiency at two Aleppo pine plantations in Spain

The Science of The Total Environment ◽

10.1016/j.scitotenv.2020.138536 ◽

2020 ◽

Vol 728 ◽

pp. 138536 ◽

Cited By ~ 7

Author(s):

Àngela Manrique-Alba ◽

Santiago Beguería ◽

Antonio J. Molina ◽

María González-Sanchis ◽

Miquel Tomàs-Burguera ◽

...

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Tree Growth ◽

Aleppo Pine ◽

Pine Plantations ◽

Drought Response ◽

Use Efficiency

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Understanding the long-term impact of prescribed burning in mediterranean-climate biodiversity hotspots, with a focus on south-western Australia

International Journal of Wildland Fire ◽

10.1071/wf18067 ◽

2018 ◽

Vol 27 (10) ◽

pp. 643 ◽

Cited By ~ 5

Author(s):

S. D. Bradshaw ◽

K. W. Dixon ◽

H. Lambers ◽

A. T. Cross ◽

J. Bailey ◽

...

Keyword(s):

Western Australia ◽

Prescribed Burning ◽

Ecological Impact ◽

Mediterranean Ecosystems ◽

Biodiversity Hotspots ◽

Protective Capacity ◽

Animal Diversity ◽

Long Term Impact ◽

The Impact

Wildfires are expected to increase worldwide both in frequency and intensity owing to global warming, but are likely to vary geographically. This is of particular concern in the five mediterranean regions of the world that are all biodiversity hotspots with extraordinary plant and animal diversity that may be impacted by deliberately imposed fire. Wildland managers attempt to reduce the impact and mitigate the outcomes of wildfires on human assets and biodiversity by the use of prescribed burning. The response that we must ‘fight fire with fire’ is understandable, perceived as reducing the flammability of wildlands in fire-prone regions and lessening the impact of wildfires. The long-term impact on biodiversity is, however, less clear. The practice of prescribed burning has been in place and monitored in south-western Australia for 50 years, longer and more intensively than in most other mediterranean ecosystems. The present target is for 200 000 ha burned each year in this biodiversity hotspot. Published studies on the impact of this burning on infrastructure protection and on biodiversity are here used to understand the protective capacity of the practice and to foreshadow its possible long-term ecological impact across all mediterranean ecosystems.

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