scholarly journals Long-term demographic fluctuations in an orchid species driven by weather: implications for conservation planning

2006 ◽  
Vol 43 (2) ◽  
pp. 313-324 ◽  
Author(s):  
MARION PFEIFER ◽  
KERSTIN WIEGAND ◽  
WOLFGANG HEINRICH ◽  
GOTTFRIED JETSCHKE
2002 ◽  
Vol 68 ◽  
pp. 257-287 ◽  
Author(s):  
Nico Roymans ◽  
Fokke Gerritsen

This study presents a survey of the long-term dynamics with regard to settlement and landscape in the Meuse-Demer-Scheldt region (south Netherlands/north Belgium), thereby using the results of several decades of intensive archaeological fieldwork. In a theoretical sense, this study is inspired by the work of historians from the French Annales school. We use a model of long-term agricultural cycles, set against demographic fluctuations, in an attempt to understand developments within the study region. At the same time, however, we aim to incorporate the social and ideational dimensions of these changes, which are linked to a specific ordering and arrangement of the landscape. Our particular focus is the radical transformation that occurred around the Middle and Late Iron Age, as this had a major impact on the ordering and arrangement of the landscape in later periods.


2018 ◽  
Vol 14 (5) ◽  
pp. 20180055 ◽  
Author(s):  
Marjolaine Rousselle ◽  
Maeva Mollion ◽  
Benoit Nabholz ◽  
Thomas Bataillon ◽  
Nicolas Galtier

Estimating the proportion of adaptive substitutions ( α ) is of primary importance to uncover the determinants of adaptation in comparative genomic studies. Several methods have been proposed to estimate α from patterns polymorphism and divergence in coding sequences. However, estimators of α can be biased when the underlying assumptions are not met. Here we focus on a potential source of bias, i.e. variation through time in the long-term population size ( N ) of the considered species. We show via simulations that ancient demographic fluctuations can generate severe overestimations of α , and this is irrespective of the recent population history.


2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Attila Molnár V. ◽  
Kristóf Süveges ◽  
Zsolt Molnár ◽  
Viktor Löki

<p>Sustainable (and adaptive) management of natural resources is usually based on long term local experiences with nature. Local traditional communities often possess rich ecological knowledge connected to nature and traditional resource use and management. This knowledge can provide unexpected new information for researchers, and show new opportunities and ways for professionals in conserving rare and threatened species.</p><p>We found significant new populations of the rare <em>Ophrys lesbis</em> in a private area next to the settlement of Çamlık, Muğla, and <em>Orchis punctulata</em> in the graveyard of Kadılar, Antalya with the help of local rural people. We firstly report the replanting of some orchid species (<em>Orchis papilionacea</em>, <em>O. italica</em>, and <em>Barlia robertiana</em>) in kitchen gardens of Çamlık and Bayır, in Muğla Province.</p><p>The presence of significant orchid populations (e.g., the biggest ever found for <em>Ophrys lesbis</em>) in an area, where local owners have been actively harvesting salep from year to year for decades suggests that the moderate salep harvesting can be sustainable for long run. Based on our observations, Turkish salep harvesters can help botanists and conservationists find new locations of rare threatened orchid populations, and therefore indirectly help in conserve these populations.</p>


Author(s):  
Emad Kaky

Abstract. Kaky E. 2020. Potential habitat suitability of Iraqi amphibians under climate change. Biodiversitas 21: 731-742. Biodiversity management and conservation planning are two techniques for reducing the rate of biodiversity loss, especially under the effect of climate change. Here 289 records of five species of amphibians from Iraq and seven environmental variables were used with MaxEnt to predict potential habitat suitability for each species under current and future conditions, using the 5th IPCC assessment  (RCP 2.6 and RCP 8.5 for the year 2050). The models suggest that annual precipitation and the mean temperature of the wettest quarter are the main factors that shape the distributions of these species. The estimated current habitat suitability was closely similar to that for 2050 under both scenarios, with a high niche overlap between them for all species. Among species, there were low niche overlaps between the frogs Bufo viridis, Hyla savignyi and Rana ridibunda, and also between the salamanders Neurergus crocatus and Neurergus microspilotus. Future sampling should focus on areas not currently covered by records to reduce bias. The results are a vital first step in long-term conservation planning for these species. Via sharing these results with decision-makers and stakeholders a crucial conservation actions need to increase Iraqi Protected Areas to avoid losing biodiversity in Iraq especially the unique populations and threaten species.


2017 ◽  
Vol 4 (1) ◽  
pp. 160647 ◽  
Author(s):  
Richard P. Shefferson ◽  
Ryo Mizuta ◽  
Michael J. Hutchings

Although many ecological properties of species respond to climate change, their evolutionary responses are poorly understood. Here, we use data from long-term demographic studies to predict evolutionary responses of three herbaceous perennial orchid species, Cypripedium parviflorum , C. candidum and Ophrys sphegodes , to predicted climate changes in the habitats they occupy. We focus on the evolution of sprouting probability, because all three species exhibit long-term vegetative dormancy, i.e. individual plants may not emerge above-ground, potentially for several consecutive years. The drivers of all major vital rates for populations of the species were analysed with general linear mixed models (GLMMs). High-dimensionality function-based matrix projection models were then developed to serve as core elements of deterministic and stochastic adaptive dynamics models used to analyse the adaptive context of sprouting in all populations. We then used regional climate forecasts, derived from high-resolution general atmospheric circulation models, of increased mean annual temperatures and spring precipitation at the occupied sites, to predict evolutionary trends in sprouting. The models predicted that C. parviflorum and O. sphegodes will evolve higher and lower probabilities of sprouting, respectively, by the end of the twenty-first century, whereas, after considerable variation, the probability of sprouting in C. candidum will return to its current level. These trends appear to be driven by relationships between mortality and size: in C. parviflorum and C. candidum , mortality is negatively related to size in the current year but positively related to growth since the previous year, whereas in O. sphegodes , mortality is positively related to size.


2019 ◽  
Vol 17 (3) ◽  
pp. 181-191
Author(s):  
Sasikarn PRASONGSOM ◽  
Kanchit THAMMASIRI ◽  
Jarunya NARANGAJAVANA ◽  
Siripong THITAMADEE ◽  
Ngarmnij CHUENBOONNGARM ◽  
...  

Dendrobium cruentum Rchb. f. is a native Thai orchid species that has faced extinction because of its attractive characteristics. Consequently, conservation of this species is urgently needed. In this study, cryopreservation technique was applied to D. cruentum Rchb. f. seeds for long-term conservation. A successful protocol for D. cruentum Rchb. f. seed cryopreservation was developed by using D cryo-plate and V cryo-plate techniques. Seed viability was tested by TCC solution and 93.8 % of dyed seeds were shown. For cryo-plate technique, seeds were encapsulated over the cryo-plate by using 2 % (w/v) sodium alginate and polymerized with 100 mM CaCl2. Encapsulated seeds were desiccated by using a laminar airflow and PVS2 solution treatment with the same exposure time (0, 30, 60, 90, and 120 min). After cryopreservation, encapsulated seeds were cultured on modified VW agar medium. From the results, the maximum germination and regrowth percentage were observed; D cryo-plate technique with 60 min of dehydration time gave the highest germination (68.9 %) and regrowth (57.8 %). Thus, the excess of dehydration may cause the reduction of germination and plant regeneration. In conclusion, D cryo-plate technique proved to be appropriate for D. cruentum Rchb. f. seed cryopreservation.


2022 ◽  
Vol 119 (3) ◽  
pp. e2116691118
Author(s):  
Shubhi Sharma ◽  
Robert Andrus ◽  
Yves Bergeron ◽  
Michal Bogdziewicz ◽  
Don C. Bragg ◽  
...  

Tree fecundity and recruitment have not yet been quantified at scales needed to anticipate biogeographic shifts in response to climate change. By separating their responses, this study shows coherence across species and communities, offering the strongest support to date that migration is in progress with regional limitations on rates. The southeastern continent emerges as a fecundity hotspot, but it is situated south of population centers where high seed production could contribute to poleward population spread. By contrast, seedling success is highest in the West and North, serving to partially offset limited seed production near poleward frontiers. The evidence of fecundity and recruitment control on tree migration can inform conservation planning for the expected long-term disequilibrium between climate and forest distribution.


Ecography ◽  
2001 ◽  
Vol 24 (6) ◽  
pp. 707-721 ◽  
Author(s):  
Carmen Diaz-Paniagua ◽  
Claudia Keller ◽  
Ana C. Andreu

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