Martin Zimmer

• Dr rer. nat. habil.
• Professor at Leibniz Centre for Tropical Marine Research

Climate change and biodiversity loss are global challenges that need to be addressed through a combination of measures. However, political and societal action has not yet kept pace with the urgency of these challenges. Marine carbon sequestering habitats ("Blue Carbon habitats") are globally recognized for their role in climate change mitigation an...

Mangroves sequester more Blue Carbon (BC) than most other marine ecosystems, making them ideal candidates for conservation and sustainable (re-)establishment, which is urgently needed due to large global losses. Deforestation rates are declining, but conservation of remaining intact forests and/or forests of high intrinsic value are still urgently...

Resource The Mangrove Restoration Tracker Tool: Meeting local practitioner needs and tracking progress toward global targets Graphical abstract Highlights d We developed the MRTT to capture data on mangrove restoration projects d The MRTT will improve data coverage and consistency between projects d The MRTT aims to stimulate data-sharing, enabling...

The re-establishment of mangrove forests is necessary to increase the quantity of sequestered carbon that would help to mitigate climate change. Determining long-term patterns of mangrove chronosequences is needed to develop a predictive capacity of carbon sequestration. We conducted a global meta-analysis of aboveground, belowground, sediment, and...

The dataset contains information on the status, sizes, and geographical range of canopy gaps in South Africa's largest mangrove forest stand at uMhlathuze, which accounts for 80% of the total mangrove coverage in the country, near Richards Bay. It also includes a smaller mangrove stand in Beachwood near Durban in the KwaZulu-Natal province. The dat...

This guide is designed as a starting point to help researchers and practitioners working in mangrove conservation and restoration who want to engage with and include LEK in their projects. This applies to, but is not limited to, members of the Global Mangrove Alliance, their collaborators, and the broader conservation community

Biodiversity loss can have significant consequences for human well‐being, as it can affect multiple ecosystem properties and processes (MEPP) that drive ecosystem services. However, a comprehensive understanding of the link between environmental factors, biodiversity, and MEPP remains elusive, especially in mangrove ecosystems that millions of peop...

Sesarmid crabs act as mangrove ecosystem engineers due to their burrowing behavior in the sediment. The burial of leaves inside the sediment suggests a positive relationship between crab activity and carbon storage in mangrove forests. However, crab burrows increase the sediment-air interface and, thus, might amplify CO 2 fluxes from the sediment....

Mangrove forest canopy gaps occur in 35 countries across the global distribution of mangrove forests in some 110 countries. Yet, their spatial and temporal patterns and drivers of their formation and closure remain poorly understood. Here, we investigated whether gaps are distributed randomly, clustered, or dispersed over space and time in two show...

This is the first systematic review and meta-analysis of blue carbon stocks in Brazilian mangroves. We evaluated the effect of characteristics and site status (impacted versus non-impacted) on carbon stocks found in the various compartments on total ecosystem carbon stock (TECS). TECS followed an inverse trend with the latitudinal position: the hig...

‘Ecosystem function’ and ‘ecosystem functioning’ became core keywords in the ecological literature on ecosystems, their structure, development and integrity. We investigate functions from the perspective of causal contributions to higher capacities, as selected effects, as contributions to the stability and self‐maintenance of organisms and as type...

Blue carbon ecosystems (BCEs) are important nature-based solutions for climate change-mitigation. However, current debates question the reliability and contribution of BCEs under future climatic-scenarios. The answer to this question depends on ecosystem processes driving carbon-sequestration and -storage, such as primary production and decompositi...

Protecting existing mangrove forests is a priority for global conservation because of the wide range of services that these coastal forests provide to humankind. Despite the recent reduction in global rates of mangrove loss, high historical loss rates mean that there are at least 800,000 ha globally that are potentially suitable for mangrove re-est...

Mangrove forests grow on soft sediments of tropical and subtropical coasts, along sheltered coastlines, bays and lagoons, or estuaries. While exposed rocky shores do not provide suitable habitats for mangroves, mangrove trees can settle in crevices of consolidated beach platforms (if wave exposure is not too extreme) or on backreefs, potentially ac...

True mangroves are vascular plants (Tracheophyta) that evolved into inhabiting the mid and upper intertidal zone of tropical and subtropical soft-sediment coasts around the world. While several dozens of species are known from the Indo-West Pacific region, the Atlantic-East Pacific region is home to only a mere dozen of true mangrove species, most...

Intensive harvesting of the mangrove crab Ucides cordatus provides subsistence for food and main or additional income to many inhabitants of mangrove areas in Northern Brazil. In order to better understand the spatial patterns of use of this natural resource as basis for sustainable resource-management, we used a combination of GPS-tracking, field...

The conservation of ecosystems and their biodiversity has numerous co-benefits, both for local societies and for humankind worldwide. While the co-benefit of climate change mitigation through so called blue carbon storage in coastal ecosystems has raised increasing interest in mangroves, the relevance of multifaceted biodiversity as a driver of car...

Decomposition of vegetal detritus is one of the most fundamental ecosystem processes. In complex landscapes, the fate of litter of terrestrial plants may depend on whether it ends up decomposing in terrestrial or aquatic conditions. However, (1) to what extent decomposition rates are controlled by environmental conditions or by detritus type, and (...

Many mangrove crab species drag freshly fallen leaf litter into their burrows and store it there for some time prior to consumption. Potential explanations for this behavior include (a) avoidance of competition for a scarce resource, (b) prevention of removal of a scarce resource upon tidal outwelling, or (c) processing of an initially unpalatable...

Mangrove forests provide a large variety of ecosystem services (ES) to coastal societies. Using a case study focusing on the Ajuruteua peninsula in Northern Brazil and two ES, food provisioning (ES1) and global climate regulation (ES2), this paper proposes a new framework for quantifying and valuing mangrove ES and allow for their small-scale mappi...

Leaf litter and its breakdown products represent an important input of organic matter and nutrients to mangrove sediments and adjacent coastal ecosystems. It is commonly assumed that old-grown stands with mature trees contribute more to the permanent sediment organic matter pool than younger stands. However, neither are interspecific differences in...

A correction to this paper has been published: https://doi.org/10.1007/s00442-021-04887-x

Mangrove sediments are particularly rich in organic matter (OM), derived from both autochthonous and allochthonous sources. Despite the recent focus of science and policy on “Blue Carbon,” understanding dynamics and fate of these OM stocks requires much more than only quantifying organic carbon in mangrove sediments. OM of different origins can be...

The ecosystem services offered by mangroves have made their protection critical. Last three decades of mangrove conservation are often relied on legal protection of existing mangroves and massive restoration/rehabilitation of degraded/reclaimed areas. Legislative protection measures are based on declaration of protected areas and descriptive regula...

For centuries, mangrove forests and adjacent ecosystems have been cast in a negative light due to their (often perceived) ecosystem disservices. We give contemporary examples of how such viewpoints about mangroves continue to be communicated today, with potentially adverse consequences for mangrove conservation and public support. Since public perc...

Mangrove ecosystems provide important ecological benefits and ecosystem services, including carbon storage and coastline stabilization, but they also suffer great anthropogenic pressures. Microorganisms associated with mangrove sediments and the rhizosphere play key roles in this ecosystem and make essential contributions to its productivity and ca...

Matang Mangrove Forest Reserve (MMFR) is one of the most productive and managed forests in the world. On the other hand, it has become a concern whether MMFR is being degraded as a result of exposure to industrial pollution. Industries located around MMFR dispose effluents contaminated by heavy metals. This study was conducted to analyze heavy meta...

Disposal of industrial wastewater has resulted in increased concentration of heavy metals (HMs) along the coastline of Malaysia. However, little is known about the accumulation capacity of HMs by Rhizophora apiculata in Matang Mangrove Forest Reserve (MMFR) Malaysia. The aim of this study is to measure the concentration of HMs in different ages of...

Presented as Oral Presentation at the 6th International Marine Conservation Congress (IMCC6), 24 August 2020: SSO-10 Estimating, protecting and enhancing the blue carbon potential of coastal oceans. This study has been published in Oecologia (https://doi.org/10.1007/s00442-021-04865-3).

Lignins are major structural components of plant cell walls and hence of plant litter. The complex polymer effectively resists chemical and enzymatic attack, even more than other important phenolic litter constituents such as condensed tannins. The enzymatic degradation of both lignin and condensed tannins depends on the oxidation of aromatic rings...

Ethnographic Data Set of the "Meaning of Mangroves"-Project: The objective of this research was to understand the co-dependent relationship of mangrove ecosystems, public mangrove discourses and the human use of mangrove areas. Research questions were: How have mangroves been made sense of around the Gulf of Guayaquil from the 19th century until t...

Physical leaf attributes such as tensile strength and toughness have proved to be good predictors of litter decomposition by invertebrates and microbes. This chapter describes two methods for assessing leaf toughness and tensile strength, respectively. Toughness is estimated by measuring the force needed to penetrate a leaf disk with a penetrometer...

Cellulose is the most abundant polymer in the living world. Its enzymatic degradation is a crucial step in the decomposition of plant litter. Despite a wide variety of enzymatic mechanisms contributing to cellulose degradation, some general patterns driven by extracellular enzymes have emerged, allowing estimates of cellulolytic activities in envir...

Mangroves play an important role in the nutrient cycle of coastal areas, contributing to the health of adjacent ecosystems by retaining carbon, nitrogen and phosphorous. Different studies have shown that sediment organic carbon (SOC) stock decrease with the loss of above-ground forest biomass. Our objective was to assess the effect of deforestation...

Mangrove forests are among the world’s most productive ecosystems and provide essential ecosystem services such as global climate regulation through the sequestration of carbon. A detailed understanding of the influence of drivers of ecosystem connectivity (in terms of exchange of suspended particulate organic matter), such as geomorphic setting an...

Warming is one of the most dramatic aspects of climate change and threatens future ecosystem functioning. It may alter primary productivity and thus jeopardize carbon sequestration, a crucial ecosystem service provided by coastal environments. Fucus vesiculosus is an important canopy-forming macroalga in the Baltic Sea, and its main consumer is Ido...

Case study for Western (Brazil) and Eastern (Cape Verde, Senegal) tropical Atlantic countries, information on marine and coastal natural resources and their use and exploitation status

The establishment and wellbeing of seedlings governs the spread and survival of mangrove forests. Eutrophication and global warming are major challenges endangering mangrove ecosystem integrity. How these stressors affect seedling growth is not well understood. In a mesocosm experiment we grew mangrove seedlings in temperature-controlled chambers a...

Understanding local patterns of species-specific litterfall can help predict spatial differences in the amount and quality of organic matter input to systems under different environmental conditions. However, little is known about the drivers of differences in litterfall production in mangroves. Here we combined data from leaf litterfall (LL) studi...

The presence of mangrove trees and crab burrows potentially contribute to localized variation in sediment elevation and affect sediment characteristics in these ecosystems, but the interacting effects of trees and burrows are largely unknown. Using a field study and artificial burrow experiment, we investigated variation in sediment redox potential...

Jellyfish blooms might be driven by the alterations in seawater temperature (SWT) associated with climate change. The physiological responses of jellyfish to changing SWT, however, are poorly understood. Therefore, we asked the question: how do sudden changes (±6 °C) in SWT affect the physiological performance of the jellyfish Cassiopea sp.? We mea...

Mangroves grow in the coastal and intertidal zones at tropical and subtropical latitudes. It is widely accepted that the establishment, growth and survival of mangrove seedling depend on the environmental conditions such as temperature, tidal regime and hydrodynamics. To date we know that, in cohesionless sediment, the higher the flow velocity the...

Multi-elemental and isotopic fingerprints could help to track changes in mangrove forest productivity and development. This study aims to identify elemental concentrations and stable isotope ratios in inter- and intra-mangrove species along the inundation gradient of the Matang mangrove forest. Matured sun leaves of different mangrove species, name...

Population declines in shark species have been reported on local and global scales, with overfishing, habitat destruction and climate change posing severe threats. The lack of species‐specific baseline data on ecology and distribution of many sharks, however, makes conservation measures challenging. Here, we present a fisheries‐independent shark su...

Decomposition processes influence the formation of soil organic carbon stocks, and it is necessary to understand how both will respond to climate change. A Space-For-Time (SFT) substitution allows the comparison of litter decomposition under current and future conditions in the field, using a spatial gradient of environmental conditions. Here we us...

The conservation of functioning ecosystems worldwide is warranted by the need for reliable and sustainable provision of ecosystem services locally, regionally and globally. Mangroves provide numerous ecosystem services both to local human communities, e.g., coastal protection or food security, and to mankind worldwide, e.g., food security or climat...

At least two thirds of all ecosystems worldwide have been impacted and changed severely by human activity (MEA 2005), mostly without considering consequences for the structure, functioning or service-provisioning of these ecosystems. The societal challenges arising from this are twofold: conserving natural heritage and resources, and at the same ti...

Plant traits have been used extensively in ecology. They can be used as proxies for resource-acquisition strategies and facilitate the understanding of community structure and ecosystem functioning. However, many reviews and comparative analysis of plant traits do not include mangroves plants, possibly due to the lack of quantitative information av...

Matrix of traits per species showing the number of records per each combination.

Mangroven sind Wälder in der Gezeitenzone tropischer und subtropischer Küs-ten beidseitig des Äquators. Sie wachsen auf schlickig-sandigen Böden in Gebie-ten, in denen die mittlere jährliche Wassertemperatur über 20 °C liegt. Weltweit gibt es etwa 140.000 km 2 , 46 % davon kommen in Süd-und Südostasien vor (Abb. 28.1). Mangroven fanden in der Verga...

Multi-elemental and isotopic fingerprints could help to track changes in mangrove forest productivity and development. This study aims to identify elemental concentrations and stable isotope ratios in inter- and intra-mangrove species along the inundation gradient of the Matang mangrove forest. Matured sun leaves of different mangrove species, name...

Many ecological processes are influenced by salinity. Burrowing crabs, abundant fauna of mangrove forests around the world, can facilitate sediment water fluxes, which may decrease the salinity in mangrove sediments. We investigated whether and how crab burrow density and secondary fine root biomass interact to drive sediment salinity during the dr...

Pathways and rates of decomposition of detrital matter partly depend on its chemical composition. Digestive processes of detritivores drive changes in the chemical composition of detritus, and these changes translate into the chemical composition of the organic matter sequestered into soils and sediments. The latter, in turn, determines how stable...

Quantifying the level of overlap between species-specific effects in a given process - i.e. their functional redundancy-remains a central issue in predicting the shape of diversity-productivity or diversity-stability relationships. We compared the indirect effects of six aboveground macro-detritivores on two belowground processes, cellulose decay a...

Pelagic jellyfish blooms are increasing worldwide as a potential response to climate-change. However, virtually nothing is known about physiological responses of jellyfish to e.g. sudden changes in water temperature due to extreme weather events. When confronted with a sudden decrease or increase in water temperature by 6 °C, medusae of Cassiopea s...

The ecological interactions that occur in and with soil are of consequence in many ecosystems on the planet. These interactions provide numerous essential ecosystem services, and the sustainable management of soils has attracted increasing scientific and public attention. Although soil ecology emerged as an independent field of research many decade...

The recent surge in research on organic carbon sequestration by seagrass ecosystems has begun to reveal the complexity of the carbon cycle within these ecosystems. In this prospective we discuss two areas of investigation that require further scrutiny: (1) why organic carbon is stabilized in seagrass sediments, and (2) how long organic carbon resid...

The study of the spatiotemporal distribution of talitrid amphipods was carried out along a transect in three stations belonging to the lagoon complex of Ghar El Melh, namely the supralittoral zones of the old harbour of Ghar El Melh, the opposite to Boughaz and Sidi Ali Mekki lagoon. Four species belonging to Talitridae family with two different ge...

Bacterial symbionts represent essential drivers of arthropod ecology and evolution, influencing host traits such as nutrition, reproduction, immunity, and speciation. However, the majority of work on arthropod microbiota has been conducted in insects and more studies in non-model species across different ecological niches will be needed to complete...

Increased human population growth threatens the ecological functioning and goods and services provided by tropical coastal ecosystems. However, a lack of scientific baselines and resources hamper efforts to develop and monitor ecological indicators of environmental change. Citizen science can provide a cost and time effective solution, but needs co...

Mangrove forests are typically located in the catchment areas of the terrestrial zone and can be adjacent to oceanic ecosystems (e.g. seagrass beds and coral reefs). These forests are thought to provide ecosystem services by retaining particulate organic matter such as detrital leaves that can facilitate nutrient-sensitive seagrass beds and coral r...

Current scenarios of global environmental change predict rapid temperature increases, which can directly affect freshwater ecosystems. Leaf litter breakdown in aquatic environments constitutes a fundamental ecosystem process that is mediated by microbial decomposers and animal detritivores. In this study, we examined interactive effects of water te...

Key messages • Soil is an important habitat for thousand millions of organisms. • Soil biodiversity is extremely diverse in shapes, colours, sizes and functions. • Soil biodiversity is globally distributed, from deserts to polar regions through grasslands, forests, urban and agricultural areas. • Soil biodiversity supports many services essential t...

SPE EA Pôle BIOME The Atlas is divided in 8 chapters covering all the aspects of soil biodiversity: - Chapter I: The soil habitat - Chapter II: Diversity of soil organisms - Chapter III: Geographical and temporal distribution - Chapter IV: Ecosystem functions and services - Chapter V: Threats - Chapter VI: Interventions - Chapter VII: Policy, educa...

Although wetlands were remarkable habitats with their fauna and flora diversity, few studies have been devoted to the study of amphipod distribution in this type of environment. To study both qualitatively and quantitatively amphipod community, surveys were conducted during the spring season in ten coastal lagoons ranging from subhumid to arid bioc...

Organisms use diverse mechanisms involving multiple complementary enzymes, particularly glycoside hydrolases (GHs), to deconstruct lignocellulose. Lytic polysaccharide monooxygenases (LPMOs) produced by bacteria and fungi facilitate deconstruction as does the Fenton chemistry of brown-rot fungi. Lignin depolymerisation is achieved by white-rot fung...

Organisms use diverse mechanisms involving multiple complementary enzymes, particularly glycoside hydrolases (GHs), to deconstruct lignocellulose. Lytic polysaccharide monooxygenases (LPMOs) produced by bacteria and fungi facilitate deconstruction as does the Fenton chemistry of brown-rot fungi. Lignin depolymerisation is achieved by white-rot fung...

Distinct habitats are often linked through fluxes of matter and migration of organisms. In particular, intertidal ecotones are prone to being influenced from both the marine and the terrestrial realms, but whether or not small-scale migration for feeding, sheltering or reproducing is detectable may depend on the parameter studied. Within the ecoton...

Seawater is a dense microbial suspension with >106 prokaryotic and >104 eukaryotic propagules per milliliter. Hence, submerged surfaces get immediately covered by biofilm-forming colonizers upon contact with seawater. Since biofilms may reduce individual fitness through decreasing motility and attractiveness or increasing shearing stress by water c...

The activity of the litter-feeding macrofauna affects litter decomposition rates at the local scale, and their preference for particular litter types is mediated by litter traits. Environmental changes such as invasion by exotic plants may change the characteristics of the litter at a local scale, with consequences to ecosystem processes. Here we e...

Background: Ecological effects of phenolic compounds in plant tissues are related to the phenolic signature, i.e. the total content and the structure of phenolic compounds. Although the spatial and temporal variation of the phenolic signature within species is well documented, it remains unclear whether intraspecific variation is due to genetic dif...

In view of current scenarios of global environmental change, we investigated the effects of warming and nutrient addition (N and P) on the impact of detritivores on density and community composition of leaf litter-colonizing bacteria in a freshwater environment. Within 10 d, detritivorous amphipods () reduced bacterial numbers at 10°C and to a less...

Whereas wrack dynamics on tidally influenced beaches have been studied to some detail, essentially nothing is known about how drift lines in tide-free coastal systems vary in space and time. We provide evidence for high spatial and temporal dynamics of beach-cast wrack on a sand beach in the Western Baltic Sea. Over the course of one year, the amou...

The amphipod communities of different wetland types belonging to three coastal lagoons complexes in northern Tunisia, Ichkeul (37◦06� to 37◦14� N, 09◦35� to 09◦56� E), Ghar El Melh (37◦06� to 37◦10� N, 10◦08� to 10◦14� E) and Korba (36◦34� to 36◦38� N, 10◦52� to 10◦54� E), were studied with respect to species composition and abundance and their rel...

Predicted changes in soil water availability regimes with climate and land-use change will impact the community of functionally important soil organisms, such as macro-detritivores. Identifying and quantifying the functional traits that underlie interspecific differences in desiccation resistance will enhance our ability to predict both macro-detri...

During the past few decades, the green crab Carcinus maenas, a native to Europe, has invaded the North American Pacific coast. In this new habitat, C. maenas encounters North American periwinkles of the genus Littorina that differ from European Littorina spp. in size, shape and shell strength. We hypothesize that the ability to handle prey never en...

In Porcellio scaber, we detected extensive oxidation of phenolics by copper-containing enzymes in the hindgut. The activity of these phenol oxidases significantly correlated with the number of bacteria in the hepatopancreas. About one quarter of the hepatopancreatic copper was localized in these bacterial cells. We conclude that copper-containing p...

Spatial subsidies have increasingly been considered significant sources of matter and energy to unproductive ecosystems. However, subsidy quality may both differ between subsidizing sources and vary over time. In our studies, sub-littoral herbivory by snails or isopods on red or brown macro-algae induced changes in algal tissues that affected colon...

To add to our understanding of species richness-effects on ecosystem processes, we studied the importance of species complementarity in driving decomposition in a saltmarsh in Georgia, USA. We studied pair-wise interactions of both detritivores and plant litter species and how they affect decomposition rates in an experiment located on the mid-mars...

Predation on detritivores is expected to decelerate detritivore-mediated decomposition processes. In field mes-ocosms, we studied whether the decomposition of leaf and needle litter of live oak (Quercus virginiana) and loblolly pine (Pinus taeda), respectively, was affected by saltmarsh detritivores (Gastropoda: Littoraria irrorata and Melampus bid...