ALPINeDNA

While many people tend to associate Greece primarily with its countless islands, the truth is that it is, in fact, a remarkably mountainous country. Most of its land area is covered by rugged terrain, dominated by peaks, ridges, and steep valleys. This vertical fragmentation gives rise to a diverse and striking landscape filled with tall mountains and deep gorges. Among these mountain ranges, the most prominent is the Pindus range, which stretches diagonally across the country from the northwest to the southeast. To the north, the densely forested Rhodope Mountains form a natural border with Bulgaria, while the towering Mount Olympus, standing at 2,917 meters, holds its place not only as the highest peak in Greece but also as the mythical home of the ancient Greek gods, making it a legendary symbol of the country's landscape.

ALPINeDNA project focuses on the Pindus Range.....

Think of the Pindus as the mountainous spine of mainland Greece. It’s not just the country’s largest mountain range, but also a geological continuation of the Dinaric Alps, stretching roughly 230 kilometers in length and up to 70 kilometers in width. It cuts diagonally across the country, from the northwest to the southeast, and even extends geologically into the Peloponnese. But Pindus isn’t one solid block of rock — it’s a complex system of smaller ranges and peaks. Among the most prominent mountains are Smolikas (2,637 m), Tymfi, Grammos, the Tzoumerka, Agrafa, and Lakmos, while its southern extensions include Vardousia, Giona, Mount Parnassus, and Oiti.

The central region of Pindus spans across the prefectures of Grevena, Ioannina, and Trikala, often referred to as the “core” of the range. Here, it’s traditionally split into Northern and Southern Pindus, offering diverse geological formations, thick forests, alpine meadows, and steep gorges.

Ecologically speaking, this mountainous habitat has faced its share of pressure over the years. Agriculture and logging have left their mark, while modern threats now include expanding tourism and the construction of ski resorts. Due to the steep slopes and glacial history of the region, you’ll also find scattered high-altitude alpine lakes—all of them frozen during the cold winters. This isn’t just scenic talk. The climate here is serious: harsh winters with heavy snowfall, thick cloud cover, and prolonged snow accumulation from October to May. Summers are cool and moist, especially higher up, and conditions change dramatically depending on elevation.

The Northern Pindus area, with its wild ridgelines and deep valleys, is carved by rivers like the Aoos and Voidomatis and dotted with small lakes. Between the rock faces and forested slopes lie traditional mountain villages, many centuries old, known for their distinct stone architecture and cultural identity.

And if you’re wondering just how ecologically important this region is—well, it's not just nationally recognized. It’s a hotspot for biodiversity on a European and even global scale. The area is home to two national parks: the Pindus National Park (Valia Kalda) and Vikos–Aoos National Park. Add to that eleven Natura 2000 protected areas, and it’s clear this place matters. A lot. 

Biodiversity....

Biodiversity in the Pindus Mountains isn’t just impressive — it’s exceptional. Let’s start with the flora. Thousands of plant species grow across the range, many of which are not only native to Greece but endemic to this specific region- meaningthey grow nowhere else on Earth. Some of the most fascinating plant communities are found on the ophiolitic (ultramafic) bedrock of mountains like Smolikas, Vasilitsa, Lygkos, and Flampouro — areas rich in heavy metals where only highly specialized plants can survive. Then come the orchids. Scattered across ridgelines, slopes, and high-altitude basins, they appear in both small and large populations, adding bursts of color and complexity to the already rich alpine scenery.

Now for the fauna. The Pindus range is a stronghold for many of mainland Greece’s large mammals. This includes rare and protected species such as the brown bear (Ursus arctos), the grey wolf (Canis lupus), the wildcat (Felis sylvestris), the Eurasian otter (Lutra lutra), the roe deer (Capreolus capreolus), and the Balkan chamois (Rupicapra rupicapra balcanica). More common species are also present in healthy numbers — wild boar (Sus scrofa), red fox (Vulpes vulpes), hare (Lepus capensis), badger (Meles meles), red squirrel (Sciurus vulgaris), stone marten (Martes foina), and the elusive pine marten (Martes martes). All in all, over 60 mammal species have been recorded in the area.

As for the birdlife, it's equally impressive: more than 180 species have been documented. Among the stars of the sky are the Egyptian vulture (Neophron percnopterus), the golden eagle (Aquila chrysaetos), the booted eagle (Hieraetus pennatus), the short-toed snake eagle (Circaetus gallicus), the peregrine falcon (Falco peregrinus), and the lanner falcon (Falco biarmicus). Rare woodpeckers also make their homes here, including the black woodpecker (Dryocopus martius) and the Balkan woodpecker (Dendrocopos syriacus).

Reptiles and amphibians are also an important part of the mountain ecosystem. About 30 reptile species live in the area — 16 lizards, 10 snakes, and 4 types of turtles. Notable examples include the Corfu wall lizard (Algyroides nigropunctatus), the four-lined snake (Elaphe quatuorlineata), and the marginated tortoise (Testudo marginata). Amphibians number around 14 species, with highlights like the fire salamander (Salamandra salamandra), the common toad (Bufo bufo), the green toad (Bufotes viridis), and the alpine newt (Triturus alpestris), which thrives in small high-altitude lakes — including the famous Drakolimnes of Smolikas and Tymfi, and the remote twin lakes of Flega.

Alpine lakes...

High up in the rugged mountains of Pindus, scattered across remote ridgelines and basins carved by ancient glaciers, lie a series of small alpine lakes — known locally as Drakolimnes, or “dragon lakes.” Despite their modest size and often barren surroundings, these lakes are ecological treasures. Found far from urban centers, they are largely shielded from direct human disturbance. That makes them rare natural laboratories: pristine, isolated, and ideal for studying how climate change and airborne pollutants affect freshwater systems over time.

Unlike lowland lakes, alpine lakes are less exposed to nutrient pollution and agricultural runoff. They're also highly sensitive to environmental stress, responding quickly to changes in temperature, acidity, and chemical deposition. Due to their cold waters, short ice-free periods, and low nutrient content, they are classified as oligotrophic ecosystems — habitats with relatively simple food webs dominated by cold-adapted, specialized species. Think of them like oceanic islands: young, isolated, and colonized only by those organisms hardy and lucky enough to reach them.

In Greece, these lakes often remain frozen for 7 to 9 months of the year. When the ice melts, strong sunlight and clear skies rapidly warm the shallow surface, but deep mixing rarely occurs — meaning temperature layers don’t form as clearly as they do in larger, lowland lakes. Their remoteness has made them understudied, but this is slowly changing as scientists recognize their importance in tracking global environmental shifts.

Biologically, these lakes are simple but fascinating. They host a limited number of species, but those species tend to occur in high numbers. One standout group? Amphibians — particularly newts. Several species have been recorded in Greek alpine lakes, such as Ichthyosaura alpestris (the Alpine newt), Triturus macedonicus, and Lissotriton vulgaris. The Alpine newt, which ranges from 659 m to over 2,300 m in elevation, thrives in these cold waters. Lacking fish (which can’t naturally reach these isolated lakes), newts sit at the top of the food chain and feed mainly on zooplankton, including crustaceans like Daphniidae, Chydoridae, and copepods (Calanoida, Cyclopoida, Harpacticoida).

They're not alone in this niche. Insect larvae — such as midges (Chironomidae/Chaoborus spp.) — also consume zooplankton, especially rotifers (Rotifera), which play a crucial role in transferring energy from primary producers, like phytoplankton, to higher levels of the food web. Despite their isolation, these alpine systems are not immune to harm. Over recent decades, airborne pollutants — including acidifying compounds, heavy metals, and organic contaminants — have made their way to even the most remote lakes. Combined with climate-driven stress, this has led to habitat degradation, species loss, and the disruption of essential ecosystem functions.

As human impacts continue to mount, understanding the full diversity and fragility of inland freshwater systems — especially in high-altitude environments — has become not just important, but urgent.

Climate, ice and a fragile balance

In alpine environments, elevation is everything. It dictates temperature, sunlight, oxygen levels, and season length — all of which shape the living conditions in these remote mountain systems. In high-altitude lakes, ice and snow cover, as well as water temperature, are tightly linked to air temperature, meaning climate plays a defining role in how these ecosystems function — and how they change.

The alpine lakes are no exception. Their hydrology is closely tied to precipitation patterns, and they exist in regions where climate gradients can be steep and fast-changing. These lakes remain frozen for much of the year — often 7 to 9 months — and during the short ice-free window, sunlight plays a critical role in water heating. But their small surface area and volume, combined with weak thermal stratification, mean that heat dynamics can shift rapidly, often pushing these systems into instability.

This is where climate change enters the picture — and not gently. These already challenging environments are walking a tightrope of balance between species and conditions. Many of the species that have adapted to these lakes are cold specialists, fine-tuned to narrow temperature ranges and low-nutrient (oligotrophic) waters. That delicate equilibrium is now at risk.

Why? Because alpine lakes are especially vulnerable to the impacts of the climate crisis. First, the increase in greenhouse gases means more solar energy is trapped at Earth’s surface. In high-altitude lakes, much of that solar radiation goes into evaporation, and with no protective tree cover and full exposure to the sun, water loss is significant. Second, the simple food webs of these lakes — with only a few species playing key ecological roles — are fragile. A single disruption, like the loss of a zooplankton species due to pollution or the introduction of a non-native predator, can cause cascading collapses throughout the system.

On top of that, climate change is not a slow, steady process. It’s increasingly erratic, marked by extreme weather shifts. That could mean longer, colder winters and thicker ice, which might challenge even the most resilient plankton species (despite their ability to enter dormancy). Or it could mean rapid warming, pushing lake temperatures above the survival threshold for many cold-adapted organisms.

To make matters worse, these lakes are often isolated from each other — sometimes by entire mountain ranges — and the microscopic species within them rely on passive dispersal (via birds, wind, or water flow) to move between habitats. If climate-driven changes render one lake uninhabitable, nearby lakes may not be accessible or viable as alternatives. That means local extinction is a real possibility —because they run out of liveable space.

Taken together, these factors create a picture of vulnerability……smthg…