Even low levels of tree cover improve dietary quality in West Africa

Forests are attracting attention as a promising avenue to provide nutritious and “free” food without damaging the environment. Yet, we lack knowledge on the extent to which this holds in areas with sparse tree cover, such as in West Africa. This is largely due to the fact that existing methods are poorly designed to quantify tree cover in drylands. In this study, we estimate how various levels of tree cover across West Africa affect children's (aged 12–59 months) consumption of vitamin A–rich foods. We do so by combining detailed tree cover estimates based on PlanetScope imagery (3 m resolution) with Demographic Health Survey data from >15,000 households. We find that the probability of consuming vitamin A–rich foods increases from 0.45 to 0.53 with an increase in tree cover from the median value of 8.8 to 16.8% (which is the tree cover level at which the predicted probability of consuming vitamin A–rich foods is the highest). Moreover, we observe that the effects of tree cover vary across poverty levels and ecoregions. The poor are more likely than the non-poor to consume vitamin A–rich foods at low levels of tree cover in the lowland forest-savanna ecoregions, whereas the difference between poor and non-poor is less pronounced in the Sahel-Sudan. These results highlight the importance of trees and forests in sustainable food system transformation, even in areas with sparse tree cover

Forest regrowth improves people’s dietary quality in Nigeria

Two billion people currently suffer from micronutrient deficiencies. Existing literature shows that forests can improve people’s dietary quality—yet forests are often overlooked in food security policies, which focus primarily on the production of staple crops. The Bonn Challenge has set a goal of restoring 350 million ha of forest by 2030, but it remains unclear whether restored forests will exhibit the species diversity needed to improve diets in the same way as existing forests. Here, we report how forest regrowth in Nigeria has affected people’s dietary quality. We combine a new map on forest regrowth with food consumption panel data from over 1100 households—and use a combination of regression and weighting analyses to generate quasi-experimental quantitative estimates of the impacts of forest regrowth on people’s food intake. We find that people living in areas where forest regrowth has occurred have a higher intake of fruits and vegetables and thus higher dietary diversity

Enhancement of Late Successional Plants on Ex-Arable Land by Soil Inoculations

Restoration of species-rich grasslands on ex-arable land can help the conservation of biodiversity but faces three big challenges: absence of target plant propagules, high residual soil fertility and restoration of soil communities. Seed additions and top soil removal can solve some of these constraints, but restoring beneficial biotic soil conditions remains a challenge. Here we test the hypotheses that inoculation of soil from late secondary succession grasslands in arable receptor soil enhances performance of late successional plants, especially after top soil removal but pending on the added dose. To test this we grew mixtures of late successional plants in arable top (organic) soil or in underlying mineral soil mixed with donor soil in small or large proportions. Donor soils were collected from different grasslands that had been under restoration for 5 to 41 years, or from semi-natural grassland that has not been used intensively. Donor soil addition, especially when collected from older restoration sites, increased plant community biomass without altering its evenness. In contrast, addition of soil from semi-natural grassland promoted plant community evenness, and hence its diversity, but reduced community biomass. Effects of donor soil additions were stronger in mineral than in organic soil and larger with bigger proportions added. The variation in plant community composition was explained best by the abundances of nematodes, ergosterol concentration and soil pH. We show that in controlled conditions inoculation of soil from secondary succession grassland into ex-arable land can strongly promote target plant species, and that the role of soil biota in promoting target plant species is greatest when added after top soil removal. Together our results point out that transplantation of later secondary succession soil can promote grassland restoration on ex-arable land

Approaches to the study of poverty and environmental impacts of conservation interventions

Reducing poverty and halting biodiversity loss are two crucial global goals. Protected areas (PAs) are an important example of how goals to reduce poverty and halt biodiversity loss interact. PAs aim to conserve biodiversity, but also have impacts on poverty. In this thesis I focus on the environmental and social impacts of protected areas using a suite of large datasets. Specifically, I focus on how our understanding of PA impacts can be improved by (1) assessing heterogeneity in more detail, (2) comparing impacts relative to impacts of other land uses, and (3) by using better data to study impacts in countries with currently insufficient data. In chapter 2 I assess how Nepali PAs influence poverty, extreme poverty, and inequality. I find that Nepali PAs reduced overall poverty and extreme poverty, and crucially, did not exacerbate inequality. I also find that tourism was a key driver in poverty reductions, but PAs also reduced extreme poverty in areas with few tourists. In chapter 3 I compare PA impacts relative to competing land uses and find that sustainable use PAs, agriculture and mining have led to different outcomes in forest cover and poverty in the Brazilian Amazon. I also show that PAs were effective in reducing deforestation compared to larger-sized landholdings, but not smallholders. I also show evidence that mining sites had more deforestation, but that mining sites also raised local income. In chapter 4 I test whether machine learning methods can be informative to estimate poverty in Tanzania using publicly available satellite imagery. I find that our machine learning methods can be used to estimate household consumption fairly accurately, but cannot be used to measure poverty change or multidimensional poverty. Combined, my findings highlight that PAs can reduce poverty and protect forests although impacts are highly heterogeneous and further scrutiny of PA impacts is needed in more countries. Novel methods using publicly available secondary data show promise to drastically improve the evidence base of PA impacts in data-poor countries where poverty is most prevalent

Impact of protected areas on poverty, extreme poverty, and inequality in Nepal

Protected areas (PAs) are key for biodiversity conservation, but there are concerns that they can exacerbate poverty or unequal access to potential benefits, such as those arising from tourism. We assess how Nepalese PAs influence poverty, extreme poverty, and inequality using a multidimensional poverty index, and a quasi‐experimental design that controls for potential confounding factors in non‐random treatment allocation. We specifically investigate the role of tourism in contributing to PA impacts. Nepali PAs reduced overall poverty and extreme poverty, and crucially, did not exacerbate inequality. Benefits occurred in lowland and highland regions, and were often greater when a larger proportion of the area was protected. Spread of benefits to nearby areas outside PAs was negligible. Furthermore, older PAs performed better than more recently established ones, suggesting the existence of time lags. Although tourism was a key driver of poverty alleviation, PAs also reduced extreme poverty in areas with fewer tourists.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146882/1/conl12576.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146882/2/conl12576_am.pd

Biotic soil characteristics of the soils at the start of the experiment, for nematodes abundances are given for their total and per feeding group (bacterial, plant, fungal feeders, omni- and carnivores).

<p>Biotic soil characteristics of the soils at the start of the experiment, for nematodes abundances are given for their total and per feeding group (bacterial, plant, fungal feeders, omni- and carnivores).</p

Codes of field sites, time since abandonment and plant association.

<p>Field age = years since abandonment. Lat. = Latitude (°N), Long. = Longitude (°E).</p>1<p>According to Schaminée <i>et al.</i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0021943#pone.0021943-Schamine1" target="_blank">[38]</a>.</p

Abiotic characteristics of the soils at the start of the experiment.

<p>Abiotic characteristics of the soils at the start of the experiment.</p