scholarly journals Traditionally managed landscapes do not prevent amphibian decline and the extinction of paedomorphosis

2019 ◽  
Vol 89 (2) ◽  
pp. e01347 ◽  
Author(s):  
Mathieu Denoël ◽  
G. Francesco Ficetola ◽  
Neftali Sillero ◽  
Georg Džukić ◽  
Miloš L. Kalezić ◽  
...  

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 479b-479
Author(s):  
James A. Schrader ◽  
William R. Graves

We are interested in the potential of seaside alder as a shrub or small tree for managed landscapes. This species has received little attention from horticulturists and occurs naturally only in small, disjunct populations in Maryland and southern Delaware (Delmarva Peninsula), northwestern Georgia, and south-central Oklahoma. Our objective is to optimize asexual (softwood cuttings and tissue culture) and sexual propagation of seaside alder while testing for differences in propagation success among populations. Terminal softwood cuttings collected 11 June 1997 (Delmarva) and 25 Aug. 1997 (Oklahoma) were treated with IBA at various concentrations and provided intermittent mist in a greenhouse for 10 weeks. Up to 44% rooting was achieved by using 1 g IBA/kg on cuttings from Delmarva; replication over time will be used to determine whether poorer rooting of cuttings from Oklahoma (maximum of 17% with 8 g IBA/kg) was due to genotypic effects or the time of collection. Strobili were collected during late 1997 from multiple plants in the three populations. Unstratified seed from Oklahoma showed from 40% to 76% germination after 21 days depending on the tree of origin. The only previous data of germination of unstratified seeds was a report of 5% to 20% for seeds from Delmarva, so provenance as well as stratification effects on germination are being evaluated.



2010 ◽  
Vol 92 (3) ◽  
pp. 93-99 ◽  
Author(s):  
JP Collins
Keyword(s):  


2009 ◽  
Vol 85 (2) ◽  
pp. 227-234 ◽  
Author(s):  
Pierre Drapeau ◽  
Antoine Nappi ◽  
Louis Imbeau ◽  
Michel Saint-Germain

Extensive even-aged management of the boreal forest and its consequences on the loss of late-seral stages (>100 years) is raising concerns about the future of organisms associated with standing deadwood. The considerable reduction of deadwood not only at the stand but at the landscape level is considered to be one of the principal causes of biodiversity loss in managed forest ecosystems worldwide. Ecosystem-oriented management approaches propose a fundamental change in forestry practices whereby live and dead tree retention becomes an important consideration in forest harvesting. We use woodpecker assemblages and their association with standing deadwood for both nesting and foraging to emphasize the importance of the entire range of snag degradation stages for maintenance of key ecological processes in habitat remnants of managed landscapes. We argue that bridging foraging and nesting knowledge of woodpecker’s snag requirements can refine conservation objectives for deadwood retention in the boreal forest. Key words: deadwood, woodpeckers, hole-nesting community, late-seral forests, keystone species, foraging and nesting tree requirements, food webs, nest webs, snag management



2014 ◽  
Vol 60 (3) ◽  
pp. 575-589 ◽  
Author(s):  
Heidi M. Rantala ◽  
Amanda M. Nelson ◽  
Jessica N. Fulgoni ◽  
Matt R. Whiles ◽  
Robert O. Hall ◽  
...  




2000 ◽  
Vol 125 (1) ◽  
pp. 128-134 ◽  
Author(s):  
James A. Schrader ◽  
William R. Graves

Genotypic variation and horticultural potential of Alnus maritima [Marsh.] Nutt. (seaside alder), a large shrub or small tree found naturally in only three small, disjunct populations, have not been studied. We examined effects of population of origin and environment on seed germination and growth and morphology of seedlings. The first experiment showed that 6 weeks of cold stratification optimized germination of half-sibling seeds from Oklahoma at 73.2%. When this treatment was applied to multiple groups of half-siblings from all populations in a second experiment, seeds from Oklahoma had a higher germination percentage (55.0%) than seeds from Georgia (31.4%) and the Delmarva Peninsula (14.7%). In a third experiment, morphology and growth of multiple groups of half-siblings from all three populations were compared in one environment. Leaves of seedlings from Oklahoma were longer (12.8 cm) and more narrow (2.15 length to width ratio) than leaves of seedlings from Georgia (12.0 cm long; ratio = 1.76) and the Delmarva Peninsula (11.6 cm long; ratio = 1.86). Seedlings from Oklahoma and Georgia accumulated dry weight at higher rates (181 and 160 mg·d-1, respectively) than seedlings from Delmarva (130 mg·d-1), while seedlings from Oklahoma and Delmarva were more densely foliated (0.72 and 0.64 leaves and lateral shoots per centimeter of primary stem, respectively) than those from Georgia (0.46 per cm). These differences indicate genetic divergence among the three disjunct populations and the potential to exploit genetic variation to select horticulturally superior A. maritima for use in managed landscapes.



Land ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 957
Author(s):  
Claudia Troiano ◽  
Maria Buglione ◽  
Simona Petrelli ◽  
Sofia Belardinelli ◽  
Antonino De Natale ◽  
...  

Mediterranean mountain landscapes are undergoing a widespread phenomenon of abandonment. This brings, as a consequence, the loss of traditional land use practices, such as transhumant pastoralism, as well as shrub and wood encroachment, with repercussions on the biodiversity associated with semi-open, human-managed landscapes. In this study, we focus on a mountain pasture from the Southern Apennines (Italy), where free-ranging transhumant grazing is still carried out, to quantify the effects of grazing presence and exclusion on arthropod diversity, and to qualitatively characterize the plant communities of grazed and ungrazed areas. Using field sampling, remote sensing, and semi-structured interviews, we assessed the validity of traditional cattle farming as a landscape management tool. Indeed, high diversity grasslands excluded from grazing were characterized by significantly less even and more dominated arthropod communities, as well as fewer plant species and families. Moreover, in areas that have been consistently grazed over the years, we found no forest encroachment from 1955 to 2019. However, rural communities are experiencing difficulties in keeping local traditions alive, even with current agri-environmental schemes. Thus, traditional livestock grazing can be a valuable management tool to maintain high biological and cultural diversity, even if stronger cooperation and attention to local needs is necessary.



2006 ◽  
Vol 131 (3) ◽  
pp. 345-351 ◽  
Author(s):  
J. Ryan Stewart ◽  
William R. Graves ◽  
Reid D. Landes

Carolina buckthorn [Rhamnus caroliniana Walt. or Frangula caroliniana (Walt.) Gray] is an attractive and water-stress-resistant shrub or small tree distributed extensively in the southeastern United States that merits use in managed landscapes. Due to substantial climatic differences within its distribution (30-year normal midwinter minima range from 13 to -8 °C), selection among provenances based on differences in cold hardiness is warranted. Before selections are marketed, the potential of carolina buckthorn to be invasive also merits investigation. Ecological problems resulting from the introduction of Rhamnus L. species in the United States, most notably the dominance of R. cathartica L. (common buckthorn) over neighboring taxa, are due in part to early budbreak. Consequently, we investigated depth of cold hardiness and vernal budbreak of carolina buckthorn and common buckthorn. Stem samples of carolina buckthorn and common buckthorn collected in midwinter survived temperatures as low as -21 and -24 °C, respectively. Although the cold hardiness of carolina buckthorns from Missouri was greater than that of carolina buckthorns from Ohio and Texas on 2 Apr. 2003, there were no differences in cold hardiness of stems from Missouri and Texas on all three assessment dates in the second experiment. All plants survived at both field locations except for the carolina buckthorns from southern Texas planted in Iowa, which showed 0% and 17% survival in 2003 and 2004, respectively. Budbreak of both species with and without mulch in Ames, Iowa, was recorded from 9 Apr. to 10 May 2002. Mean budbreak of common buckthorn was 5.7 days earlier than budbreak of carolina buckthorn, and buds of mulched carolina buckthorns broke 4.2 days earlier than did buds of unmulched carolina buckthorns. We conclude that the cold hardiness of carolina buckthorn is sufficient to permit the species to be planted outside of its natural distribution. Populations of carolina buckthorn in Ohio and Missouri should be the focus of efforts to select genotypes for use in regions with harsh winters. Phenology of its budbreak suggests carolina buckthorn will not be as invasive as common buckthorn, but evaluation of additional determinants of invasiveness is warranted.



2018 ◽  
Vol 20 (9) ◽  
pp. 2395-2420 ◽  
Author(s):  
G. Dittrich-Schröder ◽  
T. B. Hoareau ◽  
B. P. Hurley ◽  
M. J. Wingfield ◽  
S. Lawson ◽  
...  


1993 ◽  
pp. 197-204 ◽  
Author(s):  
Timothy John Ferraro ◽  
Shelley Burgin
Keyword(s):  


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