Our team
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Mark van Benthem | Director
T | +31 317 46 65 60 |
E | |
in | nl.linkedin.com/in/markvanbenthem1/ |
Read more about his: projects and publications
As a director, Mark likes to think creatively and in solutions. That, and the interaction with people is what keeps him going. In the meantime, he is our greatest idealist at Probos. With every project he checks whether it will make the world a little better, because otherwise you shouldn't do it, he believes. Always look at the impact of projects: does it contribute to good forest management, does it benefit biodiversity or the soil? It is therefore not surprising that he is much concerned with making the wood supply chain more sustainable as well as with the relationship between forest management and biodiversity.
His favorite tree or forest? "Chilean Patagonia. In an afternoon you can cycle from the temperate rainforest on the coast to above the tree line. Uphill you enter forests with alerce, the largest tree in South America, which grows very slowly and can live for thousands of years.”
Mark has international work experience in Chile, Mexico, Peru, Canada, Ukraine, Guatemala, Indonesia, Suriname, the Republic of Congo, Cameroon and Finland. He has been involved in the certification of sustainable forest management since the 1990s and has written many publications. He is co-author of several books on forest history, forest management and biodiversity, and forest expansion. Mark actively searches with partners for ways to give forests more value(s) and through this contribute to forest conservation and forest expansion.
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Nienke Welle | Senior adviser
T | +31 317 46 65 53 |
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in | nl.linkedin.com/in/nienkewelle |
Read more about her: projects and publications
Nienke studied forestry at Larenstein University of Applied Sciences and obtained a Master's degree in Landscape History from the University of Groningen. She gained many years of experience at a forestry consultancy firm, the Federatie Particulier Grondbezit (Federation of Private Land Ownership) and as an independent adviser, project leader and researcher. She is no stranger to the search for smart land use combinations that can support the realisation of new forests. She pays attention to the balance between ecological, economic and social interests in the countryside as well as to the overview of administrative relationships. (Green) heritage is also her passion, especially the history of estate management in the broadest sense of the word.
Her favorite tree or forest? "An impossible question! I love the typical Dutch small-scale cultural landscape, with old oaks or chestnuts around farms. But also old beech forests, a poplar meadow with lush undergrowth, an avenue with American oaks in autumn, the endless forests in the Black Forest."
At Probos, Nienke is mainly involved in the field of 'More forests and trees'. Her ambition is to contribute, together with partners in rural areas, to the objective of 10% more forests in the Netherlands as well as the green-blue intertwining of the landscape. You can call Nienke for questions about afforestation and everything that comes with it (such as issues surrounding spatial planning, financing, planting material and the Nature Conservation Act), but also for forest history or historical geographical themes.
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Joyce Penninkhof | Senior adviser
T | +31 317 46 65 57 |
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in | nl.linkedin.com/in/joycepenninkhof |
Read more about her: projects and publications
During her internship at Probos, Joyce conducted research into the cultural history of the Sint Jansberg. After quitting her job at Wageningen University & Research (WUR), she started at Probos in 2015. In her structured way of working, she deals with everything, both substantive and practical. She has a broad interest in everything related to sustainable forest management and is therefore a good source of information for her colleagues. She believes it is important to learn from each other and continue to take steps together in forest management, including for future generations of forests and people.
Her favorite tree or forest? "The forest on the Sint Jansberg near Groesbeek. Hilly, on an old estate. You will encounter deciduous forest, production-focussed coniferous forest, but also old ponds and other beautiful cultural-historical elements. It almost feels foreign."
Joyce has work experience in Finland, where she conducted research in peatland reforestation. Within Probos, Joyce is mainly involved in the field of 'Climate-smart forestry', such as grazing pressure monitoring research where the quantitative effect of large ungulates on forest regeneration is recorded, revitalisation and additional climate-smart tree species. She also conducts various studies and projects in the field of invasive exotic species (particularly Asian knotweeds) and she is co-initiator of the Invasive Aliens Knowledge Network. She also teaches various courses together with partners.
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Sander Teeuwen | senior adviser
T | +31 317 46 65 66 |
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in | nl.linkedin.com/in/sanderteeuwen |
Read more about his: projects and publications
His favorite tree or forest? "The old open beech forest on the Oostereng near Wageningen, with that beautiful light when the sun shines on it. Even in winter, when no one else is outside."
Sander coordinates the data provision field of work. In doing so, he makes a major contribution to producing reliable statistics and market data in the field of forests and timber; essential for formulating policy and conducting thorough research. Sander is the national correspondent on behalf of the Netherlands for data provision for international organisations such as the FAO, ITTO and UNECE as well as being a member of the European National Forest Inventory Network (ENFIN). Sander also gained work experience in the Amazon rainforest of Brazil, where he investigated the effect of logging on the regeneration of tropical tree species.
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Eli Prins | Adviser
T | +31 317 46 65 74 |
E | |
in | nl.linkedin.com/in/eliprins |
Read more about his: projects and publications
At Probos, Eli is involved in projects that focus on making the (tropical) wood chain more sustainable, forest expansion, climate-smart forests, and ecosystem services. He likes to look for integrated solutions with all parties involved, with the main goal of making a positive impact on the forest. As a nature fanatic and birdwatcher, Eli can regularly be found in forests and nature reserves from large to small, with his binoculars and camera at hand.
His favorite tree or forest? Moist forests, such as swamp forests in the dunes near Voorne and the alder forests near the St. Jansberg. Here, the mineral-rich groundwater and rich soils create a productive ecosystem where the diversity of plant and animal species can immediately be felt.
Eli has experience as a project manager of innovative projects and bringing together the 'triple helix', especially on themes related to circular economy and building chain cooperation. He also arranged several deliveries of energy systems to Ukraine. His work experience can be put to good use in realizing impactful projects at Probos, by bringing different perspectives together in projects. He has completed two MSc courses; Strategic Entrepreneurship (EUR) and Forest and Nature Conservation (WUR). During the latter, he acquired substantive knowledge about forests, including different forest types and forest ecosystems, forest biodiversity, species identification, and forest management.
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Gera op den Kelder | Adviser
T | +31 317 46 65 54 |
E | |
in | nl.linkedin.com/in/geraopdenkelder |
Read more about her: projects and publications
During her internship at Probos, in collaboration with the Ark Foundation, Gera conducted research into spontaneous forest development. Her efforts and collaboration resulted in a great assessment of her internship and we asked her if she wanted to continue working with us. She definitely liked that! At Probos, she is committed to the fields of ‘Climate-smart forestry’ and ‘More forests and trees’. Additionally, she works on calculating carbon sequestration in trees and forests as well as carbon certificates. Whatever the subject, she tackles it and is fully committed to it.
Her favorite tree or forest? “The weeping willow. Contrary to what the name suggests, I don’t think the tree is sad, but rather majestic with its size and hanging branches. For me, it conveys a certain serenity.”
Gera has also been passionate about football from an early age. There is no giving up and there is always room for improvement. She views every situation as a possibility to learn from and do better next time. This mentality is not only useful on the football field, but she also carries it into her work at Probos.
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Gino van Maaren | Adviser
T | +31 317 46 65 52 |
E | |
in | nl.linkedin.com/in/ginovanmaaren |
Read more about his: projects and publications
At Probos, Gino works on the fields of ‘Climate-smart forestry’, ‘More forests & trees’ and ‘Invasive Alien Species’. He is our go-to person for 'translating' policy and science into practical tools and easy-to-read articles and reports.
His favorite tree or forest? "The sweetgum tree. When autumn comes, a sweetgum tree changes color beautifully! If a tree has all the colors from green to yellow, orange, red and then purple, it's like looking at a fairytale tree."
Gino studied Forest and Nature Conservation at Wageningen University (WUR). During his studies he worked on, among other things, the effects of climate change on Dutch forests, the ecological effects of the return of the grey wolf to Western Europe, and rewilding in the Netherlands. Gino did his internship at Staatsbosbeheer (State Forestry Service), where he conducted research into the use of rich litter tree species as well as 'new', climate-smart tree species. He is also interested in the contribution of trees in urban areas to biodiversity, climate change adaptation and a healthy living environment.
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Jasper Velthuis | Adviser
T | +31 317 46 65 51 |
E | |
in | nl.linkedin.com/in/jasper-velthuis |
Read more about his: projects and publications
After his studies in Forest and Nature Conservation (at Van Hall Larenstein and WUR), Jasper looked for the balance between research and practice. At Probos he saw plenty of opportunities for this! So Jasper applied via an open application, after which it quickly became clear to Probos that Jasper is an asset to the team. Jasper prefers to focus on current topics and issues within forest practice, such as climate-smart forestry. And of course there are plenty of those issues within Probos.
His favorite tree or forest? “I personally have a lot of interest in the boreal forests such as those in Scandinavia. Particularly in the north of Sweden where you still encounter old forest cores with interesting structures. The entire region has a certain rough and idiosyncratic character. “
Jasper gained hands-on experience in Sweden and Switzerland during his studies. He contributed, among other things, to a project on the climate sensitivity of beech in Europe. Within Probos he is currently involved in various fields before he will specialize further. In his spare time, Jasper is a sports enthusiast and likes to push his limits. A quality that he also likes to apply in his work.
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Gryanne Hamming | adviseur
T | +31 317 46 65 58 |
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in | linkedin.com/in/gryannehaming |
Bekijk: haar projecten en publicaties
Gryanne ontdekte Probos tijdens een stage in haar bachelor Bos- en Natuurbeheer aan de Universiteit van Wageningen. Ze zette haar tanden in het bosuitbreidingsbeleid van 1986 tot begin 21ste eeuw en verdiepte zich in de vermeerdering van populieren en de biodiversiteitswaarde van dood hout. Toen al werd duidelijk dat Gryanne een kei is in het verwerken van grote hoeveelheden informatie. Bovendien geeft het haar voldoening om daar een inzichtelijk verhaal van te maken. Tijdens haar master Landschapsgeschiedenis aan de Universiteit van Groningen richtte zij zich op de historie van het landschap. Eenmaal terug in Wageningen klopte Gryanne weer bij Probos aan. Met haar bul op zak kon ze aan de slag gaan als adviseur op de werkvelden ‘Meer bomen en bos’ en ‘Toekomstbestendig bosbeheer’.
Haar favoriete boom of bos? “De erfbeplanting op Groningse boerderijen. Gemarkeerd door populieren, essen en elzen vormen de erven eilandjes in het uitgestrekte boerenlandschap. De bomen zorgen voor een prettige afwisseling in het zicht en geven de boerenerven iets veiligs en geborgens.”
Afkomstig uit het Groningse Ten Boer en met ouders afkomstig van de boerderij heeft Gryanne feeling met de mentaliteit van de agrarische sector hetgeen haar goed van pas komt bij de activiteiten rondom bosuitbreiding in het landelijk gebied.
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Robin Zwijgers | Adviser
T | +31 317 46 65 69 |
E | |
in | nl.linkedin.com/in/robinzwijgers |
Read more about his: projects and publications
As an adviser within Probos, Robin mainly works in the field of data provision. Making readable graphs from complicated data: that's what he likes. Especially when this data helps in discussions about forest management views.
His favorite tree or forest? “A pine forest on the sandy soils on a warm, dry summer day. As far as I'm concerned, an underrated forest type. A warm gust of wind with the smell of sand and pine in these woods takes me back to the holidays and summer camps of my youth.”
After an interesting bachelor's degree, Robin opted for something that better suited his interests: Dutch forests. While studying Forest and Nature Conservation at WUR, he noticed that this was the right decision and wrote his thesis at Wageningen Environmental Research (WEnR). To this end, he conducted a data analysis using data from the Dutch National Forest Inventory (Nationale Bosinventarisatie, NBI) to investigate issues about forest owners and timber harvesting. He completed his Master with an internship at Bosgroep Zuid-Nederland where he improved the height growth function of a forest growth model based on the National Forest Inventory data. Together with his interests in current affairs and developments surrounding Dutch forest management, this provided a good basis for his work at Probos.
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Sylvia Schalken | Office manager
T | +31 317 46 65 55 |
E | |
in | nl.linkedin.com/in/sylviaschalken |
With approximately 40 years of work experience under her belt and a diversity of positions, Sylvia has made her mark. But after psychiatry, the communications profession and her role as a manager in elderly care, she wanted to delve deeper into a completely new field of work. And so she chose the forest. Within Probos, Sylvia supports the advisers in the field of project management and communication. And of course she ensures that everything runs smoothly within the agency. Because planning, organising and communicating... that's just part of her.
Her favorite tree or forest? "The giant sequoias that she encountered on her travels through America. You feel so insignificant among these trees; only then do you realize how powerful and beautiful nature is.”
Sylvia likes to write. She usually does this for or on behalf of others. Except on her blog site; she publishes her own short story there every week. She is also active on various writing platforms and is developing professional storytelling skills. “By telling stories, people can inspire each other. It is with great pleasure that I bring the stories of Probos into the spotlight.”