Bilder Herpetologie Dresden

Herpetology

Research

Transforming Earth: Changing diversity in a changing world

Land-use- and climate change threaten global biodiversity

Within the scope of several projects financially supported by DFG researchers at Senckenberg Dresden are addressing pressing questions about the role of global change processes in shaping the world’s biodiversity, particularly in forest ecosystems in both temperate and tropical regions.

Climate change and intensified land-use are globally threatening important forest ecosystems.

In the North-Amazonian Guianashield, as well as in the Andean cloud forests of South America, another important model region for Senckenberg research, climate extreme events such as El Niño und La Niña interact with rapidly increasing land-use and forestry. These interactions yield sometimes unforeseen and unexpected consequences. While pristine ecosystems are being lost at dramatic rates and animal and plant species are literally vanishing before our eyes, particular species have managed to exploit newly created habitats and adapt to changing environmental conditions faster than expected.

In the last fragments of rainforest in the Uíge province in northern Angola, another focus region, however, a rapid race against time has begun. Here, the scientists of the Herpetology Section and their national and international colleagues are collecting basic biodiversity data and are fighting for the establishment of an urgently needed national park to protect Angola’s natural heritage.

These findings highlight the need for truly integrative biodiversity research as fundamental prerequisite for sustainably safeguarding global biodiversity. Global climate protection and regional/local habitat and species conservation will have to be merged and harmonized to create an urgently needed holistic nature conservation strategy in the Anthropocene. This will be the major challenge for all of us. Now and for generations to come!

Found but lost

Angola has one of the highest deforestation rates of all African countries. Deforestation is particularly prominent in Angola’s North, an area bordering the vast tropical rainforests of the Congo basin and home of the country’s last rainforest fragments. Pressure on these pristine forest ecosystems has increased dramatically and large fractions are vanishing before their hidden biological treasures can be unveiled. In a race against time, SGN researchers are currently assessing their biological diversity, in collaboration with national and international organizations, in an effort to develop and implement urgently needed protection schemes.

Funded by: MINAMB, UNEP, Paul-Ungerer Stiftung

Publications:

Ernst, R., Nienguesso, A. B. T., Lautenschläger, T., Barej, M. F., Schmitz, A., & Hölting, M. (2014). Relicts of a forested past: Southernmost distribution of the hairy frog genus Trichobatrachus Boulenger, 1900 (Anura: Arthroleptidae) in the Serra do Pingano region of Angola with comments on its taxonomic status. Zootaxa, 3795(5), 600-600.

Ernst, R., Schmitz, A., Wagner, P., Branquima, M. F., & Hölting, M. (2015). A window to Central African forest history: Distribution of the Xenopus fraseri subgroup south of the Congo Basin, including a first country record of Xenopus andrei from Angola. Salamandra, 52(1), 147-55.

Ernst, R., Lautenschläger, T., Branquima, M. F. & Hölting, M. (2020 in press). At the edge of extinction: A first herpetological assessment of the proposed Serra do Pingano Rainforest National Park in Uíge Province, northern Angola. Zoosystematics and Evolution.

Feature film: Conservation or destruction? The future of the Uíge mountain ranges 

Coffe and poison dart frog

Structurally rich shade-coffee and –cocoa plantations can harbor a significant number of amphibian species. However, species compositions are not necessarily identical with those of pristine forests. Small-scale forest fragmentation can have positive effects on species diversity. Safeguarding biodiversity in fragmented landscapes thus requires a large-scale landscape approach. Social-ecological production landscapes could thus become a key element in conservation biology in the Anthropocene. Fincas de Intercambio de Conocimiento FINCO, are one of the strategies currently tested that aim at facilitating knowledge transfer between scientist, farmers and conservationists (shade coffee on exhibition is one prominent product)

Funded through: DFG-FZT 118 & COLCIENCIAS

Publications:

Brüning, L. Z., Krieger, M., Meneses-Pelayo, E., Eisenhauer, N., Pinilla, M. P. R., Reu, B., & Ernst, R. (2018). Land-use heterogeneity by small-scale agriculture promotes amphibian diversity in montane agroforestry systems of northeast Colombia. Agriculture, Ecosystems & Environment, 264, 15-23.

Ernst, R. & Reu, Björn (2019). Food for thought: Agroforstwirtschaft und Biodiversitätsschutz in kolumbianischen Bergregenwäldern. Natur Forschung Museum 149 (1-3), 20-25.

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The cutting edge of sustainability

To date roughly 200 Mio. ha of forest in approximately 80 different countries have been certified under Forest Stewardship Council (FSC) criteria. According to their mission statement FSC promotes environmentally sound, socially beneficial and economically prosperous management of the world’s forests. But can commercial timber harvesting and biodiversity conservation really be reconciled in the face of global climate change and observed unprecedented rates of global forest loss? There are no easy answers: Very often species richness and diversity remain unchanged after selective timber harvesting. However, functional and phylogenetic diversity can be altered dramatically. They can decrease, as is the case in the investigated communities of the Upper Guinea Forest Hot Spot, West Africa or even increase as in the communities of Guiana Shield Frontier Forests of Northern Amazonia. Here, artificial habitats created by harvesting machinery can buffer diversity loss, particularly during climatic extreme events promoting selected species while others still go extinct.

Funded through:  DFG ER 589/1-1 & ER 589/2-1

Publications:

Ernst, R., Linsenmair, K. E., & Rödel, M. O. (2006). Diversity erosion beyond the species level: dramatic loss of functional diversity after selective logging in two tropical amphibian communities. Biological Conservation, 133(2), 143-155.

Hölting, M., Bovolo, C. I., & Ernst, R. (2016). Facing complexity in tropical conservation: how reduced impact logging and climatic extremes affect beta diversity in tropical amphibian assemblages. Biotropica, 48(4), 528-536.

Ernst, R., Hölting, M., Rodney, K., Benn, V., Thomas‐Caesar, R., & Wegmann, M. (2016). A frog’s eye view: logging roads buffer against further diversity loss. Frontiers in Ecology and the Environment, 14(7), 353-355.

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Caribbean invaders

Johnstone’s Whistling Frog, Eleutherodactylus johnstonei, a native of the Lesser Antilles, has a long history of human mediated range expansion, dating back to at least 1880. Today, E. johnstonei can be considered one of the most widely and successfully expanding invasive amphibian species, outperformed probably only by the cane toad Rhinella marina and the American bullfrog Lithobates catesbeianus. Despite this wide distribution, active dispersal beyond non-natural, human modified habitats could not convincingly be shown to be a realistic scenario and threats to native biota imposed by direct interactions appear to be limited. However, the co-introduction (nested invasion) of potentially pathogenic microorganims associated with E. johnstonei (E. johnstonei microbiome) can pose yet undetected threats. In this project we aim to reconstruct the origins and dispersal pathways of E. johnstonei by integrating data from native island populations into existing data sets from non-native areas and to address the problem of nested-invasions by comparing frog-specific microbiomes both within and across native and non-native distribution ranges.

Funded through: DGHT Peters Fonds

Publications:

Leonhardt F., Keller A., Arranz Aveces C., Ernst R. (2023). From Alien Species to Alien Communities: Host- and Habitat-Associated Microbiomes in an Alien Amphibian. Microbial Ecology. https://doi.org/10.1007/s00248-023-02227-5

Leonhardt F., Arranz Aveces C., Müller A., Angin B., Jegu M., Haynes P., Ernst R. (2022). Low genetic diversity in a widespread whistling alien: A comparison of Eleutherodactylus johnstonei Barbour, 1914 (Eleutherodactylidae) and congeners in native and introduced ranges NeoBiota 79: 31-50. https://doi.org/10.3897/neobiota.79.86778

Ernst, R., Massemin, D., & Kowarik, I. (2011). Non-invasive invaders from the Caribbean: the status of Johnstone’s Whistling frog (Eleutherodactylus johnstonei) ten years after its introduction to Western French Guiana. Biological Invasions, 13(8), 1767-1777.

Leonhardt, F., Jimenez-Bolaño, J. D., & Ernst, R. (2019). Whistling invaders: Status and distribution of Johnstone’s Whistling frog (Eleutherodactylus johnstonei Barbour, 1914), 25 years after its introduction to Colombia. NeoBiota, 45, 39.

Herpetologie Dresden
Herpetologie Dresden
The tiny Johnstone’s Whistling Frogs are so noisy that their nightly concerts are causing property prices to drop in some parts of South America due to noise pollution!

Citizen science

The Fire Salamander in the National Park Sächsische Schweiz – Citizen Science supports battle against Biodiversity Loss

Amphibia (frogs, newts and salamanders, caecilians) are worldwide the most threatened vertebrate group. Compared to the tropics, e.g. Brazil (with more than 1000 species) the German amphibian fauna is very poor, comprising only 22 species (18 in Saxony). Nevertheless, a global responsibility for the protection for some of these species rests with Germany.

A black-yellow mascot

The Fire Salamander (Salamandra salamandra ssp.) is Germany’s most popular native amphibian. It prefers cool and moist habitats like deciduous forests, hiding during day-time under litter and in hollows. Even in mild winters, fire salamanders can be observed. The female deposits up to 70 largely developed larvae (larvipary) in bodies of clean water. Larval development lasts 2 – 5 months, and the adults can live for up to 50 years. Some populations are life-bearing, i.e. females give birth to fully developed juveniles.

A pathogenic fungus threatens Newts and Salamanders

Despite the ongoing destruction and degradation of crucial habitats German Fire Salamander populations were comparatively stable over the past decades. However, a pathogenic fungus Batrachochytrium salamandrivorans (Bsal), which has caused dramatic population declines in Fire Salamanders in the Benelux countries has recently been recorded from Germany, with similar detrimental effects. This highly contagious fungal pathogen causes lethal skin lesions in amphibians. Most likely, it was introduced through the pet salamander trade from Southeast Asia. It has not yet been observed in Saxony. However, a thorough monitoring of the Fire Salamander populations is indispensable to be able to react quickly and mitigate potential impacts on local salamander populations.

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Fig. 1 Citizen scientist pictures  from the project:  Fire Salamander- where are you?
The patterns on the salamander’s back are as individual as a human fingerprint. This facilitates the recognition of individuals. Yellow or orange spotted or striped animals occur in the same area of Saxony where representatives of the eastern (S.s. salamandra, spotted) as well as of the western subspecies (S. s. terrestris, striped) occur. In the contact zone mixed forms are frequently observed.

Fire Salamander – where are you?

The project “Feuersalamander – wo bist Du” (“Fire Salamander – where are you”) is based on information provided by “Citizen Scientists” for the National Park “Sächsische Schweiz. Distribution, activity, size of populations and even migrations of individuals can be deduced from dated photographs and the exact location or coordinates. The Elbe Sandstone Mountains (Nationalpark Sächsische Schweiz) represent the largest continuous distribution area in Saxony. The goal of the project will be to establish an early warning system that alerts conservationists to take action in case of spreading diseases such as BSal or dramatically declining populations.

Project website