Perennial plant species from semiarid gypsum soils support higher AMF diversity in roots than the annual Bromus rubens

2012 ◽  
Vol 49 ◽  
pp. 132-138 ◽  
Author(s):  
M.M. Alguacil ◽  
E. Torrecillas ◽  
A. Roldán ◽  
G. Díaz ◽  
M.P. Torres
2017 ◽  
pp. 77
Author(s):  
Rafael Lira ◽  
Alejandro Casas

Information on use and management of wild species of Cucurbitaceae is presented, in order to analyze processes of incipient plant domestication. Ibervillea millspaughii is a perennial plant species with massive roots, distributed from Tamaulipas to Belize. Roots of this species are utilized as medicine in the treatment of arthritis, inflammations and muscular pain. Roots are commonly collected from individuals in wild populations, but, in some villages of Quinatana Roo people tolerate and enhance individuals of this plant species in anthropogenic areas; also, people cultivate this plant species in home gardens. Melothria pendula is distributed from the United States to Argentina. Fruits and young stems and leaves of this species are consumed as food and used in traditional medicine. These products are generally gathered from wild or weedy populations, but in La Montaña de Guerrero region, the tolerance of this species and the intentional dispersion of its seeds in anthropogenic areas are also common, in order to increase its availability. Use and propagation of this plant species may involve selection by people who distinguish between "bitter" and "sweet" variants, preferring the "sweet" ones. Sicyos parviflorus, Cyclanthera dissecta, C. langaei and C. ribiflora are consumed as greens by people in different regions of Mexico, who gather them from wild or weedy populations, although individual plants of these species are also tolerated in anthropogenic areas. The different forms of management identified in the species mentioned are possibly causing processes of domestication, but such processes are yet to be evaluated.


2017 ◽  
Vol 39 (1) ◽  
pp. 33 ◽  
Author(s):  
Grant D. Linley ◽  
Katherine E. Moseby ◽  
David C. Paton

Burrowing bettongs (Bettongia lesueur) reached high densities within the fenced Arid Recovery reserve. Grazing pressure was assessed by comparing the vegetation inside and outside the reserve during April in 2012, 2013 and 2014. Mean numbers of bettong tracks crossing small 10 m × 1 m plots overnight in the main exclosure were 20 in 2012, decreasing to 4 in 2013 and 3 in 2014. Similar declines were present in the second expansion, where tracks decreased from 7 in 2012 to 3 in 2013 and 2 in 2014. Perennial plant species richness decreased significantly over the study period. Acacia aneura, Acacia ligulata, Atriplex vesicaria, Crotalaria eremaea, Dodonaea viscosa, Enchylaena tomentosa, Maireana astrotricha and Sida ammophila were the most heavily grazed species within the reserve. Overall, more than 25% of plants showed some form of conspicuous grazing. C. eremaea and E. tomentosa showed little damage outside the reserve. Inside the reserve many C. eremaea were dead and heavily browsed and few E. tomentosa remained. Recent recruitment of A. ligulata and D. viscosa was also much higher outside the reserve. High densities of burrowing bettongs were associated with declines in vegetation condition potentially impacting other species and the ecosystem as a whole.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Mauro Medori ◽  
Lucia Michelini ◽  
Isabel Nogues ◽  
Francesco Loreto ◽  
Carlo Calfapietra

Most of the perennial plant species, particularly trees, emit volatile organic compounds (BVOCs) such as isoprene and monoterpenes, which in several cases have been demonstrated to protect against thermal shock and more generally against oxidative stress. In this paper, we show the response of three strong isoprene emitter species, namely,Phragmites australis, Populus x euramericana, andSalix phylicifoliaexposed to artificial or natural warming of the root system in different conditions. This aspect has not been investigated so far while it is well known that warming the air around a plant stimulates considerably isoprene emission, as also shown in this paper. In the green house experiments where the warming corresponded with high stress conditions, as confirmed by higher activities of the main antioxidant enzymes, we found that isoprene uncoupled from photosynthesis at a certain stage of the warming treatment and that even when photosynthesis approached to zero isoprene emission was still ongoing. In the field experiment, in a typical cold-limited environment, warming did not affect isoprene emission whereas it increased significantly CO2assimilation. Our findings suggest that the increase of isoprene could be a good marker of heat stress, whereas the decrease of isoprene a good marker of accelerated foliar senescence, two hypotheses that should be better investigated in the future.


Geoderma ◽  
2014 ◽  
Vol 228-229 ◽  
pp. 182-191 ◽  
Author(s):  
Amanda K. Hodson ◽  
Howard Ferris ◽  
Allan D. Hollander ◽  
Louise E. Jackson

2003 ◽  
Vol 9 (4) ◽  
pp. 302 ◽  
Author(s):  
Josh Dorrough ◽  
Julian Ash

The presence of perennial plant species in grazed habitats may be an imperfect predictor of their long-term ability to persist under grazing by livestock. This is particularly the case in landscapes where grazing by livestock is a relatively recent occurrence or where management practices are leading to intensification of grazing. This paper investigates the impacts of grazing on the native perennial inter-tussock forb Leptorhynchos elongatus (Asteraceae) in grasslands on the Monaro Tablelands of New South Wales. Although the species persists in grazed habitats, exclosures indicate that current grazing management can lead to severe depletion of seed, largely due to selective removal of flowers and seed heads by livestock. A population model suggests that under current grazing management, population growth rates may be negative. Removal of livestock during flowering and seed set may assist long-term persistence of this species in grazed habitats. Despite almost 200 years of livestock grazing on the Monaro Tablelands, recent intensification of grazing management could result in the future loss of some plant species in grazed habitats.


Plant Disease ◽  
2002 ◽  
Vol 86 (6) ◽  
pp. 573-582 ◽  
Author(s):  
R. L. Groves ◽  
J. F. Walgenbach ◽  
J. W. Moyer ◽  
G. G. Kennedy

Wild plant species were systematically sampled to characterize reproduction of thrips, the vector of Tomato spotted wilt virus (TSWV), and natural sources TSWV infection. Thrips populations were monitored on 28 common perennial, biennial, and annual plant species over two noncrop seasons at six field locations across North Carolina. Sonchus asper, Stellaria media, and Taraxacum officianale consistently supported the largest populations of immature TSWV vector species. The tobacco thrips, Frankliniella fusca, was the most abundant TSWV vector species collected, comprising over 95% of vector species in each survey season. Perennial plant species (i.e., Plantago rugelii and Taraxacum officianale) were often only locally abundant, and many annual species (Cerastium vulgatum, Sonchus asper, and Stellaria media) were more widely distributed. Perennial species, including P. rugelii and Rumex crispus, remained TSWV infected for 2 years in a small-plot field test. Where these perennial species are locally abundant, they may serve as important and long-lasting TSWV inoculum sources. In random surveys across 12 locations in North Carolina, TSWV infection was documented by double antibody sandwich enzyme-linked immunosorbent assay in 35 of 72 (49%) common perennial (N = 10), biennial (N = 4), and annual (N = 21) plant species across 18 plant families. Estimated rates of TSWV infection were highest in Cerastium vulgatum (4.2%), Lactuca scariola (1.3%), Molluga verticillata (4.3%), Plantago rugelii (3.4%), Ranunculus sardous (3.6%), Sonchus asper (5.1%), Stellaria media (1.4%), and Taraxacum officianale (5.8%). Nine plant species were determined to be new host recordings for TSWV infection, including Cardamine hirsuta, Eupatorium capillifolium, Geranium carolinianum, Gnaphalium purpureum, Linaria canadense, Molluga verticillata, Pyrrhopappus carolinianus, Raphanus raphanistrum, and Triodanis perfoliata. Our findings document the relative potential of a number of common annual, biennial, and perennial plant species to act as important reproductive sites for F. fusca and as acquisition sources of TSWV for spread to susceptible crops.


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