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Climate change dispels plants and humans to mountain heights

Thistle is invading mountain clearings; little pines are growing amongst the high alpine rocks; flocks of cattle need to climb to high altitudes for good grazing grass and water. Rise in mean global temperature primarily affects plants and animals as they slowly “seek refuge” to higher altitudes. But it primarily affects thousands of mountain people, native or traditional communities that see their livelihoods changing at a fast pace. More discretely than polar ice caps, mountains are the barometers of runaway climate change.


“We already have stone pine trees on the peak of Clocher d’Arpette in the massif of Mont Blanc at 2800 meters (9200 ft.) altitude. They are taller than 1.5 meters (5 ft.), that is a significant height, so they could be considered trees,” states Cristophe Randin, research associate at the Center for High Altitude Research (CREA) in Chamonix, France.

Diapositive 1Two decades ago such a statement would have been unconceivable or at least met with scepticism whilst today it is a trend in virtually all alpine regions of the world, Randin explains. Rising temperatures due to climate change seem to be the cause and, beyond ecological outcomes, they bring about social change, they affect businesses, communities, and, generally, mountain livelihood.

Plants are the first to adapt to the temperature increase; they change their seasonal cycles and slowly move upwards to better conditions of water, nutrients and temperature. These phenomena create different conditions for agriculture or animal husbandry at higher altitudes. And people follow plants.

“There is a link between this shift of grazers and cattle, on one hand, and climate change, on the other. All the upper limits of plant species are currently shifting to higher elevations because plants try to find and track their optimal climate conditions and, of course, this will trigger with the shift of cattle with this vegetation,” Randin says.


Shepherds, the ad-hoc scientists

Transylvanian shepherd. Photo: 2C
Transylvanian shepherd. Photo: 2C

Information related to the upward shift of vegetation in the mountains, though non-scientific, lies with the pastoral communities, with shepherds that make a living herding the sheep or cattle on the mountain grazing lands. Carpathian shepherds have to take the cattle from lower altitudes towards higher ones.

From 1,400 meters (4,600 ft.) […] we have to take them to 1,600 (5,250 ft.) or even 1,800 (5,900 ft.),” says Vlad Petru, a Romanian shepherd in the Transylvanian Alps. The higher pastures became richer in grass in the last two decades. “Yes, richer, but there is water there. And the climate is cooler; the heat here is too much,” says the shepherd.

Dry thistle “has climbed the mountain” in the last 20 years, Petru complains. It used to be lower, merely in the plough lands, he adds. He also observed for 17 years a retreat of the snowcaps on the summits of Retezat, in the Southern Carpathians, and the spruce line gaining altitude, but losing the lower altitude areas to the expansion of the beech forests. Other shepherds confirm it. Moreover, some wild cherry trees and plum trees in the high orchards blossom and ripen half a month earlier, apparently influencing bee keeping.

All this might sound like false science, but such observations have a scientific value. Cristophe Randin says that the concept is named citizens’ science.


Democratic science

In the post-truth era of Trumpism and of negationism, citizens gather up democratically and serve the scientific truth. It bears the name of citizens’ science of climate change. And it is a new and democratic approach to biosphere research. It comes as a version of big data analysis and it assesses the impact of climate change on thousands of species and their habitats. “The observations on biodiversity can be made by the public; observers that worked for 10 years on gathering data become experts or connoisseurs of different plant or animal patterns, however they do not know statistics or other methodologies,” says Randin. And, he underlines, “this is where PhDs from universities come in and mine the data.”

Such data collection and interpretation of results are part of the science of phenology.

Phenology is the study of the timing of annually recurring natural events. In seasonal climates both plants and animals have distinct seasonal cycles and it is relatively simple to record the beginning and sometimes the end of these events known as phenophases. A tree will have phenophases such as leaf budburst, leaf and flower development in spring, fruiting in summer, and leaf coloration and leaf fall in autumn. “Anybody with a reasonable ability to identify species and the time to make regular observations can contribute to phenological recording.” And many phases are temperature dependent. “Consequently many species have clearly shown changes in phenology as a consequence of rising temperatures in recent decades. […] The sheer volume and duration of phenological data have made them useful for studying the effects of a changing climate on biological systems.” (Andrew Millington, Mark Blumler, Udo Schickhoff ed., The SAGE Handbook on Biogeography, SAGE Publications, 2011, p. 236)

Citizens’ science and phenology are “in the trend of big data; if you have a big amount of data you will get closer to scientific accuracy and be able to make models for plant reactions to climate change,” says Randin. “It is not leisure, nor a joke; it is accepted by many scientific journals, data collected by citizens can do hardcore science for very long periods of time,” adds Randin taking pride in the 30,000 valuable phenological observations collected in a decade for the project Phenoclim.

“Academic research in ecology is usually temporary and opportunistic: it depends on quick funding, it lasts around 3-5 years, it ignores the cryosphere (over 3000 meters / 9,850 ft. altitude), and it has no continuity. Probably the most notable exception is the research carried out at the University of Colorado at Boulder that spread over four decades,” says Randin.


America vs. Europe, Rockies vs. Alps

At Niwot Ridge in the American Rockies, “we are also finding that plants are moving uphill into talus areas,” says, for 2C, Professor Katharine Suding from the Institute of Arctic and Alpine Research at the University of Colorado Boulder.

However, the professor thinks it is likely not just a temperature effect, “but the lengthening of the growing season. Microbes that live in the unvegetated talus are important helpers to the plants able to move into these stressful areas,” Suding adds.

Quite differently than in the European mountains, “it looks like the plants lower down are not being affected, in fact diversity has been quite stable. Trees are not moving up much here as colonization is limited by the increasing dry hot summers,” says Suding.

The trends in temperature variability in the Alps are comparable to the differences recorded in the Himalayas; there is a 0.6 centigrade increase per decade warming of the average alpine temperature at least in the Swiss, Austrian and German Alps, says Ecoclimatology Professor Annette Menzel from Technische Universität München while summarizing her decade long research at the Schneefernerhaus research facility on the German summit of Zugspitze (2,962 meters / 9,718 ft.).

But, Menzel says, the fact that affects vegetation to a larger extent is the variability of temperature between seasons and between different areas. Menzel worked for the 4th Assessment Report of the IPCC on deriving footprint of climate change on nature and she observed a direct link between zones of higher temperature and radical changes in nature: earlier spring, longer vegetation periods, changes in productivity, changes in the ranges of species, invasive vegetation and different composition of ecosystems.

After research of phenological data of different endemic species at various altitudes in the Bavarian Alps, Menzel came to the conclusion that “for forest vegetation, the growing season is lengthening: one degree increase in average temperature translates into two more weeks of growing season.” Species react differently, “beech might profit from this longer growing season, while spruce does not,” she adds.

An interesting situation is the fact that local Bavarian farmers did not change the days of hey cutting over the last decades whereas flowering does change. As opposed to Carpathian shepherds or phenology observers mentioned by Randin, “that means for us that farmers do not track climate change as they could do,” mentions Menzel. This should be looked more into detail in the future, she concludes.


Paradox of hope on a warming planet

Conversely, local communities in Nepal, together with UNDP experts from the Ecosystems-Based Adaptation in Mountain Program, have observed that some of the non-timber forest products that were promoted, such as Timur are plants that do better in cooler temperatures. “Due to rising temperatures, especially in the lower altitudes in the Panchase region where we work in Nepal, we are promoting cultivation of Timur to communities located in over 2,000 meters (6,500 ft.) above sea level,” says Tine Rossing, Knowledge Manager at the UNDP.

It is a real plan of adaptation. “As Timur currently grows best in altitudes ranging from 1,200 – 2000 meters (3,900 – 6,500 ft.), we figure that if the temperature increases, the communities in that altitude will have a relatively resilient livelihood income for the longer-term,” concludes Rossing.

Just the same, the upward shift of grazers to higher altitudes in the Eastern European mountains is plain climate change adaptation, thinks Randin. And he adds, “in some regions of the Alps the subalpine grasslands are disappearing due to non-use abandonment and the forest is invading. So the availability of open areas for grazing is decreasing at the moment.” Nonetheless, mountain communities in the Alps are far from being dependent on animal husbandry or subsistence agriculture.

“Climate change can be seen as an opportunity. There is an increasing demand for alternative energies and there is a higher productivity of [sustainable] biomass in the forest,“ adds Randin.

One thing that is different in alpine areas in the United States, mentions Suding at her turn, “is that people do not live and utilize them as intensively as in Europe. The main connection made to people is via biodiversity conservation, recreation, and downstream water (the last is a very large concern in the Western US).”

Why is it necessary to research biodiversity in mountain areas? Over 25% of the plants in alpine areas are above the tree line, on the alpine meadows. These latter ones are spread over only 3% of Europe’s surface. The tree line limit is there where the average temperature is at over 6.5 centigrade for at least three months of the year; above this line there is the alpine zone. On Zugspitze, for instance, where Professor Menzel is researching, there are no less than 164 endemic species on an apparently poor dry rocky plateau.

There was indeed a long period of work on glaciology, paleontology, but much less on ecology at altitudes of over 1200 meters, mentions Randin.

Mountain regions support many different ecosystems and have among the highest species richness globally, which play a significant role in biospheric carbon storage and carbon sequestration, they are “water towers” for billion of people, are home to numerous indigenous communities, experience higher warming temperatures, and altogether show a higher vulnerability to climate change. It is the reason for which the Mountain Partnership called upon the Contracting Parties to the UNFCCC to address in an explicit manner the key role and vulnerability of all mountainous areas in the meetings following the Paris Accord and a substantive way in its implementing – in a manner comparable with other very vulnerable areas such as small islands and low lying coastal areas.

Knowledge and scientific initiatives have to be exported, ends Randin; “[…] each mountain has its own climate, each mountain range might react differently to climate change. There is thus a need to export and to multiply this kind of initiatives and maybe something could be done.” Beyond their majestic greatness, mountains show an incredible fragility.

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