Senckenberg Research

Plenary talks

1. Question: How do earth system processes affect climate? How did climate change affect ecosystems, ecological communities and human societies in the past?

Plenary Talk 2 (Mon, Oct. 2nd, 13:00-13:30):

The role of biological processes in modulating the Earth’s climate and the evolution of land plants

Page Chamberlain

(Stanford University)

The modulation of the Earth’s climate is controlled by the balance between volcanic outgassing of carbon dioxide and the weathering of silicate rocks. It has been shown that the strength of this negative feedback has increased through time due to biogenic processes. We examine how the evolution of plants affected feedback strength by coupling a onedimensional vapor transport model to a reactive transport model of silicate weathering. We find that: 1) increased transpirational fluxes and vapor recycling increases weathering fluxes over a minimally vegetated world by a factor of 2.0 when gymnosperms colonized the Earth; and 2) silicate weathering fluxes increase by a factor of 4 to 7 by the establishment of gymnosperms due to increased soil carbon dioxide.

 

Plenary Talk 3 (Mon, Oct. 2nd, 13:30-14:00):

Tropical Climate Dynamics and Civilizations

Gerald Haug

(Max-Planck-Institute for Chemistry)

Serious efforts in paloeclimate reconstructions allow the link between high-quality climate data with archeological information to study the impact of climate on societies. We and others find a strong relationship between climatically induced changes in environmental conditions and social, political, and economic responses in several parts of the world during the past millennia. One tropical climate archive with an appropriate memory for the most relevant sub-centennial to sub-decadal scale climate swings is the anoxic Cariaco Basin off northern Venezuela. Millimeter to micrometer-scale geochemical data in the laminated sediments of the Cariaco Basin have been interpreted to reflect variations in the hydrological cycle and the mean annual position of the Intertropical Convergence Zone (ITCZ) over tropical South America during the past millennia. These data with decadal to (sub)annual resolution show that the Terminal Collapse of the Classic Maya civilization occurred during an extended dry period. In detail, the Cariaco record reveals evidence for three separate droughts during the period of Maya downfall, each lasting a decade or less. The sediments of lake Huguang Maar in coastal southeast China provide a data set of comparable quality and resolution. They record the strength of winter monsoon winds at subdecadal resolution over the last 16 thousand years. The record indicates a stronger winter monsoon prior to the Bølling‑Allerød warming, during the Younger Dryas, and during the middle and late Holocene, when cave stalagmite oxygen isotope data indicate a weaker summer monsoon. The anti-correlation between winter and summer monsoon strength is best explained by migrations in the ITCZ that occurred simultaneously in central America and Africa. Drought associated with southward ITCZ migration may have played a role in the termination of several Chinese dynasties. A remarkable similarity of ITCZ migration in east Asia and the Americas from 700 to 900 AD raises the possibility that the coincident declines of the important Tang Dynasty in China and the Classic Maya in Central America were catalyzed by the same ITCZ migrations.

 

2. Question: How do earth system processes and climate affect the macroevolution of taxonomic lineages and ecological communities? How does genomics change our view on evolutionary processes?

Plenary Talk 5 (Mon, Oct. 2nd, 15:00-15:30):

How genomics is transforming our ideas of species and biodiversity

James Mallet

(Harvard University)

It was a seductive idea that eukaryote species are isolated, independent evolutionary units, but new genomic data strongly disproves this. It's still unclear how extensively hybridization and introgression blurs the eukaryotic tree of life, but suggestive new genomic data tend to show that many species, and even non-sister species, might often exchange substantial fractions of their genomes. Adaptively evolving genes may be particularly prone to transfer. Natural hybridization is of course restricted to groups of related species that retain at least partial sexual compatibility. However, many lineages diversified initially in such small but successful groups of related species. Rapid evolutionary radiations, such as those that led to the origins of our planet's major groups of animals and plants, will have been most prone to genetic exchange. These findings are revolutionizing our understanding of species, phylogeny, and biodiversity.

 

Plenary Talk 8 (Tue, Oct. 3rd, 13:00-13:30):

Species interactions – past, present and future – what we know and what we still need to learn

Catherine Graham

(Eidg. Forschungsanstalt für Wald, Schnee und Landschaft WSL)

The impacts of climate and land-use change will increasingly affect biological diversity, species interactions, and ecosystem services. One key question is how the changes in species identity, composition, and abundance will alter trophic interactions.  Network ecology aims to quantify interactions of species in a given assemblage, but rarely addresses changes in interactions across time and space. These interactions, such as a pollinator visiting a given plant species, form the architecture of biodiversity, and understanding this architecture requires knowledge of both the generation and maintenance of interacting lineages individually as well their interactions.  Using hummingbirds and their food plants, I review what we have discovered about the past, present and future of the diversity of species interactions and provide perspectives on how we can scale-up local studies to develop a predictive geographic framework for interaction diversity and beta-diversity.

 

3. Question: How have ecosystems and ecological communities changed over long-time scales? What are the implications for conservation of ecosystems and species today and in the future?

Plenary Talk 4 (Mon, Oct. 2nd, 14:30-15:00):

Humboldt Interrupted: detecting mass extinctions in the disciplinary gap

Pincelli Hull

(Yale University)

The fossil record provides direct evidence of the history of life and the earth system.  It tells of planetary revolutions, like the evolution of photosynthesis and rise of oxygen, and of the existence of diversity as novel as dinosaurs. Fossils also show how biodiversity is lost –with the most profound instances ranking as mass extinctions.  As the impacts of humanity on the biosphere accumulate, many have looked to the past and called our current crisis among the greatest of the great– the so-called Sixth Mass Extinction. Whether this is indeed the case, is not immediately clear. Rather, the information needed to fully understand past mass extinctions and to diagnose the present-day fall between the disciplines of ecology, evolutionary biology and paleontology.  With examples from the Cretaceous-Paleogene mass extinction and the marine fossil record, I will explore this Humboldtian gap.  Hope for our future biosphere lies in the dynamics of life on these intermediate time scales.

 

4. Question: How do past and present-day changes in ecosystems and ecological communities affect conservation and ecosystem services for humans today and in the future? How do we engage at the interfaces between science, policy and society? How can science be effective in policy-making and decision-making?

Plenary Talk 1 (Mon, Oct. 2nd, 09:30-10:00):

Connections between people and nature in the Anthropocene

Georgina Mace

(University College London)

Growing human populations and demands for resources are placing unprecedented pressures on nature. Many kinds of responses have been developed to manage or reduce the impacts, and even to reverse negative trends. But if humans are the dominant driving force affecting the natural systems on which the same humans depend, then there is a need to do more. I will review approaches based around the SDGs, the natural capital approach and ecological network theory to see how in a complex, linked human-nature system it should be possible to do more than mitigate damage, and instead to restore, reclaim and manage nature.

 

Plenary Talk 9 (Tue, Oct. 3rd, 13:30-14:00):

From Local Observations to Global Assessment of Biodiversity and Ecosystem Function

Walter Jetz

(Yale University)

Biodiversity and ecosystem functions are undergoing rapid changes worldwide, with serious implications for human well-being and sustainability. Information about type, magnitude, and location of changes remains severely limited, despite the substantial societal and economic benefits such knowledge holds and its central role for understanding both causes and consequences of ongoing change. Data and information gaps severely constrain knowledge about status and trends in biodiversity and ecosystem function. However, new sensor and tracking technologies combined with advanced modelling approaches now have the potential to provide a vastly superior evidence base for future decision-making. These advances allow us to leverage and generalize natural history observations and measurements of the sort Humboldt pioneered and bring us closer to a truly contiguous and quantitative capture of the global biodiversity dynamics he had envisioned.

 

5. Question: How do scientific collections contribute to and shape geobiodiversity research? What are the opportunities and challenges for scientific collections in the future?

Plenary Talk 6 (Tue, Oct. 3rd, 09:00-09:30):

How physical conditions shape plant traits – experiments Humboldt might have done, had he stayed at home

Susanne Renner

(Ludwig-Maximilians-University Munich)

During his travels, A. von Humboldt quantified fundamental links between physical and biotic environments; at home, he carried out self-experiments involving low oxygen exposure and underwater high pressure suits. Observations on the spatial distribution of traits, however, can get us only so far. Using common garden experiments and hierarchical Bayesian modeling to incorporate phylogeny, Constantin Zohner and I have investigated leaf-out, bud set, and chlorophyll break-down in 400 species of trees and shrubs from E North America (ENA), E Asia, and Europe. Results show that ENA species innately have 3-week shorter vegetative seasons than the other species, leaving-out later, but breaking down their chlorophyll earlier. With experimental warming, trees finished their bud set earlier(not later!). These results highlight regional climate as a selective factor and underscore that local adaptations will remain ‘invisible’ unless we combine indirect comparative approaches with experiments.

 

Plenary Talk 7 (Tue, Oct. 3rd, 09:30-10:00):

Scientific collections are a planetary insurance policy

Jonathan L. Payne

(Stanford University)

Earth is currently experiencing an interval of rapid and substantial global change that threatens global biodiversity, climate stability, and the future of human society. The system being threatened is the product of four billion years of co-evolution between life and Earth. Scientific collections are critical for preserving the future of the biosphere. They uniquely enable us to know the processes that built the biosphere, to determine the environmental circumstances of past global catastrophes, and to reconstruct the processes of extinction and subsequent recovery. Scientific collections are also our incidental archive of diversity recently lost and our library of living diversity. They will soon be our primary building blocks for resurrecting extinct species and restoring ecosystems.

 

6. Question: How do we engage at the interfaces between science and society?

Plenary Talk 10 (Tue, Oct. 3rd, 19:30-21:00):

Science and Society in the Anthroprocene

Klaus Töpfer
(IASS Potsdam)

  1. In March 2012 the cover of TIME Magazine: "10 Ideas that are changing your life" Idea No. 9: "Nature is over" (Bryan Walsh).
  2. 10 years before in 2002 Paul Crutzen published a short paper in NATURE: "The Geology of Mankind". His argumentation: Science and technology decoded the construction pattern of nature with the consequence: mankind has to be considered as a "quasi-geological force" (Potsdam Memorandum 2007). Mankind is no longer in the holocene but in an "anthropocene".
  3. This argumentation has huge consequences for science and society. "Nature is over" is one these consequences. Paul Crutzen comes to the consequence that a "daunting task" lies ahead of scientists and engineers to guide society through the era of the anthropocene. To correct, to "repair" the unintended side effects of human behavior:  the urgent need for Geo-Engineering on a large scale.
  4. Society will be being confronted with "path dependencies" linked with the scientifically based decisions in the past and leads to a fundamental reduction of alternatives to choose for the future. Therefore the anthropocene requests an "appropriate human behavior" leading to a new power structure in society.
  5. These considerations are of highest actuality in our world of fake news. The complexity of scientific research and findings has to be linked with trust and confidence. It questions the functioning of an open, parliamentarian democratic system.
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