BOSQUE TROPICAL PERENNIFOLIO PDF

Download scientific diagram | Sitios de estudio en el bosque tropical perennifolio de México (Inventario Nacional Forestal, ) from publication. DIVERSIDAD DE FRUTOS DE LOS ÁRBOLES DEL BOSQUE TROPICAL PERENNIFOLIO. DE MÉXICO. Acta Botánica Mexicana, núm. 90, , pp. Key words: cloud forest, coniferous forest, GARP, tropical evergreen forest, bosque mesófilo de montaña, bosque tropical perennifolio, GARP, Veracruz.

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Climate change and effects on vegetation in Veracruz, Mexico: Recibido en junio de trpoical Reactivado en febrero de Aceptado en marzo de According to the last report of the Intergovernmental Panel on Climate Change, human activities are the main responsible for global warming due to the increase in the atmospheric concentration of greenhouse gases. This process is already causing changes in the geographical distribution of species as well as alterations in phenology.

With this background, it is interesting to study the expected trends of change to be displayed by flora and fauna perenniifolio face the new environmental conditions. This paper explores the likely changes in the composition of the main vegetation types in the state of Veracruz, Mexico under a climate change scenario. We analyzed the geographical and ecological patterns of change in a group of 51 characteristic species commonly associated to tropical evergreen forest, coniferous forest and perennkfolio forest present in Veracruz.

The approach followed was based on the technique of ecological niche modelling carried out with the Genetic Algorithm for Rule-set Production GARP and variables of future climatic condition located by in time estimated for an A2 scenario which is devised for a situation where humanity would be generating medium to high emissions. The results also suggest that some species may be extirpated from the state of Veracruz under the conditions expected bywhile a few others may find right conditions to increase their distribution.

The fourth report of the Intergovernmental Panel on Climate Change Anonymous, recognizes human activities as the main causes of global warming, provides high certainty for its existence and establishes that its effects are already under way.

Climate change means that new long term environmental regimes shall emerge, with the potential to challenge plant populations in their ability to survive under the new conditions, both through acclimatization, if these are present within their potential niches Vetaas,or by adaption if new conditions are beyond their potential niche Holt, ; Holt and Gaines, There are only a few general alternatives for the survival of the species in response to climate change: If species are capable of rapid evolutionary change or have a wide range of physiological tolerance, it is possible that adaptation or acclimation to changing environmental conditions take place.

If species are sufficiently mobile, we can continuously trace the geographical relocation perennlfolio their ecological niches Pearson and Dawson, ; Engler et al. Ecological niche modelling ENM has become a basic tool for the study of changes in the geographical and ecological distributions of species to global climate change Pearson and Dawson, ; Peterson et al. Among a wide variety of algorithms that are currently available Elith et al. This is an evolutionary computational algorithm which has been extensively tested on the prediction of the geographical distribution of species Anderson et al.

Additionally, their behavior on extrapolation exercises is well documented Peterson, a, b; Peterson et al. Mexico is a bosqye where biotas of Nearctic and Neotropical origin are mixed. Many species reach here the boundary of their distribution range as an expression of the limit of their physiological tolerance.

The impacts were estimated as distribution range shifts area size, altitude and latitude in the tropical evergreen forest, coniferous forest and cloud forest sensu Rzedowski,present in the state of Veracruz. The trkpical location of the state of Veracruz gives a setting of tropical characteristics, but these are modified in part by the influence of the peremnifolio ranges, mainly in the west; climates therefore vary from very hot to very cold. Precipitation ranges from less than millimeters mm per year in some places in the north to about mm in the south.

This environmental variation makes Veracruz one of the most biologically diverse states in the country. Almost all vegetation types described for Mexico are found here Rzedowski, Based on the Ecological Niche Modelling approach, we developed potential future distribution ranges of the major components of the main vegetation types in the state of Veracruz and surroundings areas.

The idea we pursue assumes that the sum of climatic niches of individual species autoecology could allow the reconstruction of communities to a certain degree, considering that they share similar environmental requirements.

Bosque Tropical Perennifolio de México – video dailymotion

We also used this approach to analyze the current conditions under which species live and to make projections under different scenarios of global development. The overall goal was to describe the trends of change in the vegetation distribution, assuming the physiological range documented should allow to accurately predict expected changes in distribution, because the current human induced climate change rropical apparently giving almost no chance to genetic adaptive development Holt, Selection of species and vegetation types.

We generated a list of plant species mainly trees dominant and characteristic of either coniferous forest, cloud forest or tropical evergreen forest through a thorough review of literature about the vegetation of the state of Veracruz. The references used for this purpose were: From the groups obtained from MVSP, we made a selection of species for coniferous, cloud and tropical evergreen forest.

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Finally, the selected species were considered characteristic frequent in the case of tropical evergreen forest or non-dominant associated that we regarded representative of each vegetation type, according blsque the literature reviewed.

Georeferenced localities perenmifolio specimens of each of the selected species were obtained from the herbarium XAL of the Institute of Ecology, A. GARP generates a niche model for a species, aiming to characterize the environmental conditions under which it is estimated that the species should be able to thrive. Hence, it assumes that under those conditions the species is able to maintain populations without immigration Stockwell and Peters, Although MAXENT is another algorithm commonly used, the bosqhe between these two algorithms should not be a cause for concern Tsoar et al.

For the troopical of the ecological niche of the selected species, we used extreme temperatures and precipitation values temperature of the warmest and the coldest month, precipitation of wettest blsque driest month.

Bosque Tropical Perennifolio de México

Climatic variables such as pedennifolio temperature, minimum temperature and precipitation can be particularly useful, since they coincide with physiological tolerances at regional scales Peterson and Cohoon, ; Parra et al. However, a combination of climatic and topographic features such as elevation and slope often produces better results Parra et al. The modelling training region was established based on the idea that the species have the ability to disperse to certain geographical areas as long as they have the chance e.

We used estimated values for both current conditions and forecasts under a development scenario A2 according to projections produced by the Canadian Centre for Climate Modelling and Analysis CCCMA.

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Climate variables were combined with record points of selected species and models were generated by GARP. To produce a delimitation of the coniferous and cloud forests maps, we used the species considered as dominant to generate a consensus map with the sum of these species, whereas with the remaining non-dominant species we generated the other consensus map.

Next, we overlaid the resulting dominant and associated species consensus maps and we obtained a final map that was produced by intersecting these two maps. In the case of the tropical evergreen forest, the overlap of the consensus maps was similar but for this vegetation type, all species were considered the same in terms of their dominance. To establish whether our representation of modeled vegetation resembled natural vegetation units to a certain degree, we compared the maps obtained with the map of primary vegetation Anonymous,which is defined as vegetation that would develop in an area under similar environmental conditions to the current ones, without human influence.

Finally, to assess possible future impact of the vegetation types studied here, we contrasted the map of vegetation and land use of the state of Veracruz Castillo-Campos et al. We regarded the surface in our potential vegetation maps outside of the current vegetation type maps of Veracruz we produced as the area susceptible to climate change under the chosen scenario.

EL CIRCULO MAGICO DE MEXICO: BIODIVERSIDAD SORPRENDENTE DE GUADALAJARA

Five of them likely will not encounter right conditions for their survival within the limits of Veracruz. In the case of coniferous forest, the potential perennifolik distributions of the selected species do not show a common trend.

While some species increase their potential distribution in the state of Veracruz, the distribution of others decrease, probably indicating a mixture of lineages from contrasting biogeographical affinities. However, the species that could be more affected towards is Pinus oocarpa nearcticwhile the species that is more likely to survive is Fuchsia microphylla neotropical Table 2.

We found that most of the selected species characteristic of cloud forest are likely to decline by Certainly, the critical factor is the potential loss of humidity, which is highly influential for this community. It is noteworthy that Quercus laurina is the only species of this group that could find better conditions for its sustained presence within Veracruz by Table 3. As a way to assess the accuracy of our findings, we overlaid tropocal potential distribution models obtained with the corresponding vegetation map of current land use and vegetation.

For the coverage of tropical evergreen forest Fig. Finally, the average values of the coverage of all vegetation types, as projected trolical present conditions towards those expected inthroughout the region of Veracruz and neighboring states, suggest an overall latitudinal shift southwards, although showing different levels of magnitude for each vegetation type.

There is also a displacement to areas fropical higher elevation in the tropical evergreen forest to m and cloud forest to m.

This seems to match the rising trend of the strip of fog that has already been described Still et al. In the case of the coniferous forest, we found a likely shift trooical lower elevation in to m. The analysis perenniolio potential future distribution ranges of plant communities has been the subject of various studies and discussions Osborne et al. One consequence of this has been an increase of discrepancies on the predictions of the future distribution of forests in Mexico and thus on the various possible levels of impact that will have climate change on the different vegetation types in the country.

After applying a sensitivity model, the results obtained by Villers and Trejo suggested that more than half of Mexico would suffer changes in temperature and precipitation conditions. They also noted that the tropical evergreen forest may show an increase in its surface in the future.

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The substantial reduction in potential distribution of tropical evergreen forest in the region of Veracruz byas well as in the neighboring states, suggests that changes in temperature and precipitation could be excessive for the physiological tolerance of thermophilic species.

Given that the physiology of these plants has a high synchrony with temperature and also a high requirement of adequate moisture throughout the year, species in the humid tropics may probably have a oerennifolio ability to acclimate to global warming Deutsch et al.

Likewise, Wright trlpical al.

Moreover, the increase in the potential distribution of coniferous forest we found for Veracruz and boosque neighboring states is consistent with the findings of Ni in the region of Tibet. He also observed that despite the large area reduction of temperate desert and alpine steppe, among others, there was a sizable expectation of a large increase in the area of temperate-cold coniferous forest, temperate grasslands and shrub, and temperate steppe.

They also noted that the cloud forest may advance over coniferous and oaks forests. These blsque, beyond coincidence with our results, are interesting because they highlight the new interactions that plant communities are likely to face in the near future. We could explain this expected trend of the coniferous forest by considering perrnnifolio these forests have a wide ecological span as they thrive in arid, tropjcal and frankly wet climates, and they may be found from sea level to the upper limit of tree growth Rzedowski, In this regard, we believe that the likely dynamics of the species in response to climate change will more likely take place species by species rather than whole assemblages, as suggested by Thomas et al.

We have to keep in mind that, in addition to physiological tolerances, the potential displacement of each species will be associated with many other factors. For instance, its ability to encompass their life cycle, as well as their opportunity to interact with pollinators and dispersers. Equally important perennifplio be the physical availability of locations where to establish, all of which are not part of the forecast approach we used. We hypothesize that species distribution might change at first instance by biotic interactions with animal species or environmental factors involved in their dispersal.

Hence, perennifolko potential consequence may be the modification of the assemblages of species by the changing ambient conditions. In contrast, eight species show some sort of increase in potential distribution. In addition, they present a greater perennifolioo on the potential distribution of tropical species, mainly found in the coastal plains, as compared to species of montane areas, most of which do not show such severe losses in potential distribution.

Ferreira de Siqueira and Peterson perenbifolio, also observed this difference in the impact of warm tropical environments compared to temperate species. Peterson balso pointed out that the species from the plains will be most affected by climate change. However, even if the species characteristics of tropical vegetation show a significant loss bosquue potential, based on their likely future distribution tropicl the apparent rearrangement of sympatry between plant species, the results of this study suggest likely rearrangements that could modify ecological dominance of current component species, resulting in new species patterns in tropical vegetation types.

Although the models obtained bosaue this paper take into account the characteristic composition of the vegetation types analyzed, our results suggest a possible future emergence of new vegetation types. The loss or reduction of the current dominant species or of those that characterize each vegetation type might take place, but the vegetation phenology will largely tropcial. In this transformation, some species that might currently be non-dominant might find better conditions in tropifal future and become dominant to characterize new vegetation types.

If we would like to encourage the preservation of any kind of vegetation, we should consider changes in land use as well as the distance and the barriers that the composing species must overcome in order to be able to colonize and settle in new areas.

Even if the plant species retain their ability to produce fertile propagules, it will be necessary to maintain corridors to facilitate the dispersion towards new climatic zones. The results of this study emphasize the critical importance of safeguarding connectivity by increasing the area and density of networks of protected ecosystems in regions where sources of dispersion are small and widely distributed Opdam and Wascher, ; Da Fonseca et al.

Therefore, we suggest that in order to minimize the potential loss of plant community members in the future, it is required to change the current static conservation approach towards a new one that undertakes a dynamic adaptive ecosystem management scheme that recognizes the current spatial reconfiguration stage pressing over the plant communities.

The current demands highlight connectivity in addition to the needs of rehabilitation, reforestation and restoration. Ecosystem conservation and management in times of climate change will have to re-design a strategic approach perennifolio these elements.

It should facilitate the preservation of species currently comprising natural communities, by allowing fast movement so they can quickly colonize and establish ttopical new geographical areas, and there they can continue evolving.

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