Mariana C Rufino

Technical University of Munich | TUM · Life Sciences Systems

The physicochemical conditions observed in streams and rivers result from intricate interactions among various factors, including underlying geology, soil composition, hydro-climatic characteristics (such as rainfall amount and duration), vegetation cover, and human activities. Although streams and rivers exhibit common traits globally, the distinc...

Cocoa production is a leading driver of deforestation in the humid-tropics of West Africa. Reconciling climate change mitigation with livelihoods of farmers requires identification of production strategies to concurrently improve yield and profit while curtailing emissions of greenhouse gases (GHG). Using a 2021 plot-survey conducted in Ghana’s E...

Land use is a key driver of the ongoing biodiversity crisis and therefore also a major opportunity for its miti-gation. However, appropriately considering the diversity of land-use actors and activities in conservation assessments and planning is challenging. As a result, top-down conservation policy and planning are often criticized for a lack of...

Europe imports large amounts of soybean that are predominantly used for livestock feed, mainly sourced from Brazil, USA and Argentina. In addition, the demand for GM-free soybean for human consumption is project to increase. Soybean has higher protein quality and digestibility than other legumes, along with high concentrations of isoflavones, phyto...

Tropical montane forests are fragile ecosystems that provide a wide range of ecosystem services including hydrological services, biodiversity protection and storing carbon in the above and belowground and soils contributing to climate change mitigation. The world's tropical montane forests are increasingly exposed to degradation and their recovery...

Deforestation poses a major threat to the tropical montane forest ecosystems of East Africa. Montane forests provide key and unique ecological and socio-economic benefits to the local communities and host diverse flora and fauna. There is evidence of ongoing deforestation and forest clearance in these montane forests although estimates diverge amon...

Regional effects of farming on hydrology are associated mostly with irrigation. In this work, we show how rainfed agriculture can also leave large-scale imprints. The extent and speed of farming expansion across the South American plains over the past four decades provide an unprecedented case of the effects of rainfed farming on hydrology. Remote...

Chilling can decrease stomatal sensitivity to abscisic acid (ABA) in some legumes, although hormonal mechanisms involved are unclear. After evaluating leaf gas exchange of 16 European soybean genotypes at 14°C, 6 genotypes representing the range of response were selected. Further experiments combined low (L, 14°C) and high (H, 24°C) temperature exp...

Crop improvement is a key innovation area in the pursuit of sustainable food systems. However, realising its potential requires integration of the needs and priorities of all agri-food chain stakeholders. In this study, we provide a multi-stakeholder perspective on the role of crop improvement in future-proofing the European food system. We engaged...

Crop breeding is one of the main tools which can assist in future-proofing food systems for more sustainable outcomes. In order to ensure priorities are aligned with the needs and wants of food system actors, it is essential to engage with key stakeholders to understand preferences on plant breeding solutions. This study presents results from a ser...

Tanzania’s dairy sector is poorly developed, creating reliance on imports for processed, value-added dairy products and threatening food security, particularly when supply chains are disrupted due to market volatility or armed conflicts. The Tanzanian Dairy Development Roadmap is a domestic development initiative that aims to achieve dairy self-suf...

Livestock are an important source of livelihoods in agricultural systems in sub-Saharan Africa (SSA), while also being the largest source of national greenhouse gas (GHG) emissions in most African countries. As a consequence, there is a critical need for data on livestock GHG sources and sinks to develop national inventories, as well as conduct bas...

Smallholder farm-households produce most of the crop and livestock products consumed in developing countries. Equitable transitions to low emissions food production will depend on policies that promote a reduction of greenhouse gases (GHGs) whilst improving these farmers’ livelihoods. Here, using survey data and simulation modelling, we show that T...

Key message • This brief explains the impacts of conversion of indigenous forest to small- and large-scale agriculture on water, carbon and nutrient cycles, and the implications for forest, water and land health. • Our long-term research in the Mau forest of Kenya quantified the negative effect of forest encroachment and poor agricultural practice...

The 4th Global Food Security conference highlighted four major developments: the shift from food security to food systems; a focus on diets and consumption patterns; the importance of unknown futures and inherent uncertainties and risks; and the central role of multi-level connections between local-and global-oriented research. These shifts highlig...

Restrictions on social interaction and travel due to the COVID-19 pandemic have affected how researchers approach fieldwork and data collection. Whilst online focus groups have received attention since the 2000s as a method for qualitative data collection, relatively little of the relevant literature appears to have made use of now ubiquitous video...

Large-scale modelling underscores the need to reduce phosphorus fertilizer application in rich countries and increase it in poor regions. Yet, the realization of associated economic and environmental benefits will require complementary analyses locally.

Catchments are complex systems, which require regular monitoring of hydro-chemical parameters in space and time to provide comprehensive datasets. These are needed to characterize catchment behavior on a local level, make future projections based on models, implement mitigation measures and meet policy targets. However, many developing countries la...

A growing body of evidence shows that more intensive dairy systems can be good for both nature and people. Little research considers whether such systems correspond with local priorities and preferences. Using a mixed methods approach, this study examined the effects of three intensification scenarios on milk yield and emission intensities in Kenya...

Restrictions on social interaction and travel due to the COVID-19 pandemic have affected how researchers approach fieldwork and data collection. Whilst online focus groups have received attention since the 2000s as a method for qualitative data collection, relatively little of the relevant literature appears to have made use of now ubiquitous video...

Restrictions on social interaction and travel due to the COVID-19 pandemic have affected how researchers approach fieldwork and data collection. Whilst online focus groups have received attention since the 2000s as a method for qualitative data collection, relatively little of the relevant literature appears to have made use of now ubiquitous video...

Agricultural catchments in the tropics often generate high concentrations of suspended sediments following the conversion of natural ecosystems. The eroded fine particles are generally enriched with carbon (TC) and nutrients (TN and TP) originating from the topsoil of agricultural land. Sediment-associated TC, TN and TP are an important loss to the...

Climate and land-cover change will directly impact future species distributions, leading to range expansions, contractions and local extinctions. However, assessments of future range shifts rarely account for the capacity of the landscape matrix to facilitate species dispersals. Here, we assessed future range shifts for a suite of critically endang...

Increasingly, resource managers and planners seek to manage forested landscapes for the value of the services they provide. This is especially true in the Mau Forest of Kenya, a montane area that harbors some of Kenya’s most important headwaters but has lost a quarter of its forest cover since 1999. While managing for the Mau Forest’s landscape ser...

We use an attributional life cycle assessment (LCA) and simulation modelling to assess the effect of improved feeding practices and increased yields of feed crops on milk productivity and GHG emissions from the dairy sector of Tanzania’s southern highlands region. We calculated direct non-CO2 emissions from dairy production and the CO2 emissions re...

Citizen science is gaining popularity as a way to engage people to participate in environmental projects. In addition to potential challenges regarding data quality and the choice of variables, a key factor in the success of participatory monitoring projects is the active participation of volunteers, the “citizen scientists.” To learn more about th...

Ecohydrological processes in tropical rainforests are insufficiently understood and existing studies yield contradictory results. We investigated relative contributions of different soil depths to tree water uptake of 83 trees and possible species‐specific differences in a 50x50 m forest plot at four dates in a tropical montane forest in Kenya usin...

Catchments in the tropics often generate high concentrations of suspended sediments following the conversion of forests to agriculture. The eroded fine particles are generally enriched with carbon and nutrients originating from the topsoil. Sediment associated carbon and nutrients are an important loss to the terrestrial ecosystem and tightly conne...

We use an attributional life cycle assessment (LCA) and simulation modelling to assess the effect of improved feeding practices and increased yields of feed crops on milk productivity and GHG emissions from the dairy sector of Tanzania’s southern highlands region. We calculated direct non-CO 2 emissions from dairy production and the CO 2 emissions...

Crop-livestock farms across Africa are highly variable due to agroecological and socioeconomic factors, the latter shaping the demand and supply of livestock products. Crop-livestock farms in Africa in the 21st century are very different from most mixed farms elsewhere in the world. African crop-livestock farms are smaller in size, have fewer lives...

High nitrogen (N) supply is required for high‐yielding soybean, but low soil temperatures in either early production systems or cool environments delay nodulation and limit biological nitrogen fixation (BNF). Because cytokinins are key signalling hormones in mediating nodule formation and our initial controlled environment experiment indicated that...

Land use change is known to affect suspended sediment fluxes in headwater catchments. There is however limited empirical evidence of the magnitude of these effects for montane catchments in East Africa. We collected a unique 4-year high-frequency data set and assessed seasonal sediment variation, water pathways, and sediment response to hydrology i...

In many parts of Africa, soil erosion is an important problem, which is evident from high sediment yields in tropical montane streams. Previous studies in Kenya pointed to a large contribution from catchments cultivated by smallholder farmers. This led to the hypothesis that unpaved tracks and gullies are the main sediment sources in smallholder ag...

Deforestation and land-use change are accelerating in the Congo Basin and elsewhere in the tropics affecting the soil-atmosphere exchange of greenhouse gases (GHG). There is a lack of data from Central Africa. We quantified fluxes of CO2, CH4, and N2O at the soil-atmosphere interface in a secondary forest, a cocoa agroforest, and an unfertilized cr...

Under the current political and regulatory environment, animal-sourced foods will remain part of the least-cost nutritious diet in the United States. The consumption of animal-sourced foods (ASF) is controversial, drawing debate between defenders and critics of livestock farming, and capturing public and media attention. This debate is important fo...

This letter is in press, together with a response by Viglizzo et al. to our comments relating to their original paper. The 3 of them are better interpreted as a set.

This is (the introduction for) the presentation for EGU Online 2020, where we present the results of an experiment in which we tested the validity of diurnal variations in nitrate and dissolved organic carbon concentrations measured with in situ UV-Vis spectrophotometers. Find the full interactive presentation here: https://t1p.de/EGU2020-12537.

In situ spectrophotometers measuring in the UV-visible spectrum are increasingly used to collect high-resolution data on stream water quality. This provides the opportunity to investigate short-term solute dynamics, including diurnal cycling. This study reports unusual changes in diurnal patterns observed when such sensors were deployed in four tro...

Complex and costly discharge measurements are usually required to calibrate hydrological models. In contrast, water level measurements are straightforward, and practitioners can collect them using a crowdsourcing approach. Here we report how crowdsourced water levels were used to calibrate a lumped hydrological model. Using six different calibratio...

Abstract Reducing ammonia emissions is one of the most difficult challenges for environmental regulators around the world. About 90% of ammonia in the atmosphere comes from agricultural sources, so that improving farm practices in order to reduce these emissions is a priority. Airborne ammonia is the key precursor for particulate matter (PM2.5) tha...

Rainwater harvesting and associated storage is essential for cattle ranching in the drylands of Argentina and elsewhere. This is the first study to attempt to quantify the hydrological inflows and losses from rainwater harvesting impoundments. To address the direct effect of cattle within impoundments, a typical cattle-affected impoundment was inst...

Sub‐Saharan Africa (SSA) could face food shortages in the future because of its growing population. Agricultural expansion cause forest degradation in SSA through livestock grazing, reducing forests carbon (C) sinks and increasing greenhouse gas (GHG) emissions. Therefore intensification should produce more food while reducing pressure on forests....

Machine learning has arisen with advanced data analytics. Many factors influence crop yield, such as soil, amount of water, climate, and genotype. Determining factors that significantly influence yield prediction and identify the most appropriate predictive methods are important in yield management. It is critical to consider and study the combinat...

Hydrological monitoring is essential to guide evidence-based decision making necessary for sustainable water resource management and governance. Limited hydrometric datasets and the pressure on long-term hydrological monitoring networks make it paramount to explore alternative methods for data collection. This is particularly the case for low-incom...

Livestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches i...

Hydrological models are widely used to predict catchment runoff, but they require comprehensive (and expensive) discharge observations for model development and testing. For many catchments, particularly in less developed countries or in remote areas, such data is not available. Water levels can however be easily measured by citizens to collect dat...

The promotion of agroforestry as a mitigation practice requires an understanding of the economic benefits and its acceptability to farmers. This work examines the agro-ecological and socio-economic factors that condition profitability and acceptance of agroforestry by smallholder farmers in Western Kenya. We differentiate the use of trees according...

In the last 40 years, large areas of the Mau forest, the largest contiguous tropical montane forest in East Africa, have been cleared for agriculture. To date, there are no empirical data on how this land use change affects carbon dioxide (CO2) fluxes from soil respiration and soil methane (CH4) fluxes. This study reports measured annual soil CO2 a...

Increasing demand for food and the shortage of arable land call for sustainable intensification of farming, especially in Sub-Saharan Africa where food insecurity is still a major concern. Kenya needs to intensify its dairy production to meet the increasing demand for milk. At the same time, the country has set national climate mitigation targets a...

Plant roots sense drying soil and send long-distance signals(such as plant hormones) to the shoot to limit water loss (by closing the stomata and restricting leaf growth) and increase crop water use efficiency (yield produced per unit of water applied or transpired). These signals can be modified by altering irrigation volume(how much water), frequ...

The aim of the methodology developed in these guidelines is to introduce a harmonized international approach assessing nutrient flows and impact assessment for eutrophication and acidification for livestock supply chains taking the specificity of the various production systems involved into consideration. The methodology strives to increase underst...

Conversion of natural forest (NF) to other land uses could lead to significant changes in catchment hydrology, but the nature of these changes has been insufficiently investigated in tropical montane catchments, especially in Africa. To address this knowledge gap, we aimed to identify stream water (RV) sources and flow paths in three tropical monta...

Objective: The study aimed at quantifying seasonal and spatial variations in availability and nutritive value of herbaceous vegetation on native pastures and supplement feedstuffs for domestic ruminants in Western Kenya. Methods: Samples of the herbaceous pasture vegetation (n=75) and local supplement feedstuffs (n=46) for cattle, sheep, and goa...

Successfully meeting the mitigation and adaptation targets of the Paris Climate Agreement (PA) will depend on strengthening the ties between forests and agriculture. Climate-smart land use can be achieved by integrating climate-smart agriculture (CSA) and REDD+. The focus on agriculture for food security within a changing climate, and on forests fo...

Although water is involved in many ecosystem services, the absence of monitoring data restricts the development of effective water management strategies especially in remote regions. Traditional monitoring networks can be expensive, with unaffordable costs in many low-income countries. Involving citizens in monitoring through crowdsourcing has the...

Reducing greenhouse gas (GHG) emissions from agriculture has become a critical target in national climate change policies. More than 80 % of the countries in Sub-Saharan Africa (SSA) refer to the reduction of agricultural emissions, including livestock, in their nationally determined contribution (NDC) to mitigate climate change. The livestock sect...

This study aims to explain effects of soil textural class, topography, land-use and land-use history on soil GHG fluxes in the Lake Victoria region. We measured GHG fluxes from intact soil cores collected in Rakai, Uganda, an area characterized by low-input smallholder (<2 ha) farming systems, typical for the East African highlands. The soil cores...

Land use change alters nitrate (NO3-N) dynamics in stream water by changing nitrogen cycling, nutrient inputs, uptake and hydrological flow paths. There is little empirical evidence of these processes for East Africa. We collected a unique 2-year high-resolution dataset to assess the effects of land use (i.e. natural forest, smallholder agriculture...

Conversion of natural forest to other land uses could lead to significant changes in catchment hydrology, but the nature of these changes has been insufficiently investigated in tropical montane catchments, especially in Africa. To address this knowledge gap, we identified stream water sources and flow paths in three tropical montane sub-catchments...

Region: East Africa. Focus: A review of catchment studies (n = 37) conducted in East Africa evaluating the impacts of Land Use and Land Cover Changes (LULCC) on discharge, surface runoff, and low flows. New hydrological insights: Forest cover loss is accompanied by increased stream discharges and surface runoff. No significant difference in stream...

Limited data exists on emissions from agriculture-driven deforestation, and available data are typically uncertain. In this paper, we provide comparable estimates of emissions from both all deforestation and agriculture-driven deforestation, with uncertainties for 91 countries across the tropics between 1990 and 2015. Uncertainties associated with...

Key messages • Low-cost, reliable methods for monitoring water levels and water quality are needed to assist water-resource managers in their decision-making. • ‘Citizen scientists’ willing to take part in simple monitoring activities can expand the data sets in understudied regions. • We worked with citizens in a remote Kenyan catchment who contri...

Studies that quantify nitrous oxide (N2O) fluxes from African tropical forests and adjacent managed land uses are scarce. The expansion of smallholder agriculture and commercial agriculture into the Mau forest, the largest montane forest in Kenya, has caused large-scale land use change over the last decades. We measured annual soil N2O fluxes betwe...