There is an increasing evidence that smallholder farms contribute substantially to food production globally, yet spatially explicit data on agricultural field sizes are currently lacking. Automated ...field size delineation using remote sensing or the estimation of average farm size at subnational level using census data are two approaches that have been used. However, both have limitations, for example, automatic field size delineation using remote sensing has not yet been implemented at a global scale while the spatial resolution is very coarse when using census data. This paper demonstrates a unique approach to quantifying and mapping agricultural field size globally using crowdsourcing. A campaign was run in June 2017, where participants were asked to visually interpret very high resolution satellite imagery from Google Maps and Bing using the Geo‐Wiki application. During the campaign, participants collected field size data for 130 K unique locations around the globe. Using this sample, we have produced the most accurate global field size map to date and estimated the percentage of different field sizes, ranging from very small to very large, in agricultural areas at global, continental, and national levels. The results show that smallholder farms occupy up to 40% of agricultural areas globally, which means that, potentially, there are many more smallholder farms in comparison with the two different current global estimates of 12% and 24%. The global field size map and the crowdsourced data set are openly available and can be used for integrated assessment modeling, comparative studies of agricultural dynamics across different contexts, for training and validation of remote sensing field size delineation, and potential contributions to the Sustainable Development Goal of Ending hunger, achieve food security and improved nutrition and promote sustainable agriculture.
This paper demonstrates a unique approach to quantifying and mapping agricultural field size globally using crowdsourcing. A campaign was run in June 2017 where participants were asked to visually interpret very high resolution satellite imagery from Google Maps and Bing using the Geo‐Wiki application. The results show that smallholder farms occupy up to 40% of agricultural areas globally, which means that, potentially, there are many more smallholder farms in comparison with the two different current global estimates of 12% and 24%. The global field size map and the crowdsourced data set are openly available.
Net primary production (NPP) is considered by the world scientific community as an important indicator that reflects the features of the condition and peculiarities of the functioning of forest ...ecosystems. It also allows quantifying the potential of forests in performing their ecosystem functions. The information basis of the research consists of data from the industrial database of the Ukrainian State Forest Management Planning Association – IA "Ukrderzhlisproekt". The dataset contains the biometric description of stands in the study region. Also, a system of mathematical models, algorithmic support, and software for quantitative assessment of net primary production are utilized within this research. As a result, the research determines the quantitative values of the total volume and specific intensity of formation of net primary production in the forests of the Kyiv region. The total volume of NPP in the forests of the region exceeds 6.5 million tons of dry matter, of which 56 % is accounted for by forests dominated by Scots pine. The highest mean values of primary production per unit area are observed in stands composed of tree species belonging to the hardwood broadleaved species group (black locust, hornbeam, European ash, and common oak, 1550 – 1910 g·(m2)-1). The highest intensity of organic matter production is observed in the stands of V to VIII age classes. Highly productive stands generate a major part of forest NPP in the study region. Among forest types, the highest intensity of the bioproduction process is observed in fresh hornbeam-oak and fresh hornbeam-oak site types – 1872 g∙(m2)-1 and 1646 g∙(m2)-1, respectively. The forests subordinated to the State Agency of Forest Resources of Ukraine concentrate the largest volumes of annually formed organic matter. The lowest productivity is typical for forest plant communities under the control of the Ministry of Defense of Ukraine. The research results will serve as an informational basis applicable to the formation of a strategy for sustainable use of ecosystem functions of the forests in the study region.
Biomass structure is an important feature of terrestrial vegetation. The parameters of forest biomass structure are important for forest monitoring, biomass modelling and the optimal utilization and ...management of forests. In this paper, we used the most comprehensive database of sample plots available to build a set of multi-dimensional regression models that describe the proportion of different live biomass fractions (i.e., the stem, branches, foliage, roots) of forest stands as a function of average stand age, density (relative stocking) and site quality for forests of the major tree species of northern Eurasia. Bootstrapping was used to determine the accuracy of the estimates and also provides the associated uncertainties in these estimates. The species-specific mean percentage errors were then calculated between the sample plot data and the model estimates, resulting in overall relative errors in the regression model of −0.6%, −1.0% and 11.6% for biomass conversion and expansion factor (BCEF), biomass expansion factor (BEF), and root-to-shoot ratio respectively. The equations were then applied to data obtained from the Russian State Forest Register (SFR) and a map of forest cover to produce spatially distributed estimators of biomass conversion and expansion factors and root-to-shoot ratios for Russian forests. The equations and the resulting maps can be used to convert growing stock volume to the components of both above-ground and below-ground live biomass. The new live biomass conversion factors can be used in different applications, in particular to substitute those that are currently used by Russia in national reporting to the UNFCCC (United Nations Framework Convention on Climate Change) and the FAO FRA (Food and Agriculture Organization’s Forest Resource Assessment), among others.
Recurrent wildfires in Ukraine exert severe impacts on the environment, human health and security as well as damage to private and public assets. From 2007 to 2020, the frequency of large wildfires ...has increased and reached a level that has not occurred previously. The period during April-October 2020 was the worst in modern Ukrainian history for the occurrence of catastrophic fires, e.g. in the Chernobyl Exclusion Zone (67 000 ha), Zhytomyr oblast (43 000 ha), Lugansk oblast (35 000 ha) and Kharkiv oblast (8 000 ha). In Ukraine there is the additional problem of open burning, mainly burning agriculture residues, which covers two million hectares (ha) annually. State forestry enterprises who are responsible for the management of 71% of the Ukrainian forests (7.6 million ha)and agricultural holdings are also responsible for the management of 41.3 million ha of croplands. The remaining forest users manage forest areas of 3.1 million ha within reserves and national nature parks. This article presents a brief overview of the problem of forest fires as well as of fires in other landscapes in Ukraine, and includes a critical reviews of the current wildfire management system and a description of the main features of the national wildfire management strategy. It also highlights the results of a survey of numerous stakeholders conducted on landscape fires in Ukraine. Based on the review of global and regional experiences, as well as existing fire risks in Ukraine, recommendations were developed for implementing an integrated landscape level national fire management approach.
Spatially explicit information on forest management at a global scale is critical for understanding the status of forests, for planning sustainable forest management and restoration, and conservation ...activities. Here, we produce the first reference data set and a prototype of a globally consistent forest management map with high spatial detail on the most prevalent forest management classes such as intact forests, managed forests with natural regeneration, planted forests, plantation forest (rotation up to 15 years), oil palm plantations, and agroforestry. We developed the reference dataset of 226 K unique locations through a series of expert and crowdsourcing campaigns using Geo-Wiki ( https://www.geo-wiki.org/ ). We then combined the reference samples with time series from PROBA-V satellite imagery to create a global wall-to-wall map of forest management at a 100 m resolution for the year 2015, with forest management class accuracies ranging from 58% to 80%. The reference data set and the map present the status of forest ecosystems and can be used for investigating the value of forests for species, ecosystems and their services.
During December 2020, a crowdsourcing campaign to understand what has been driving tropical forest loss during the past decade was undertaken. For 2 weeks, 58 participants from several countries ...reviewed almost 115 K unique locations in the tropics, identifying drivers of forest loss (derived from the Global Forest Watch map) between 2008 and 2019. Previous studies have produced global maps of drivers of forest loss, but the current campaign increased the resolution and the sample size across the tropics to provide a more accurate mapping of crucial factors leading to forest loss. The data were collected using the Geo-Wiki platform ( www.geo-wiki.org ) where the participants were asked to select the predominant and secondary forest loss drivers amongst a list of potential factors indicating evidence of visible human impact such as roads, trails, or buildings. The data described here are openly available and can be employed to produce updated maps of tropical drivers of forest loss, which in turn can be used to support policy makers in their decision-making and inform the public.
Several global high-resolution built-up surface products have emerged over the last five years, taking full advantage of open sources of satellite data such as Landsat and Sentinel. However, these ...data sets require validation that is independent of the producers of these products. To fill this gap, we designed a validation sample set of 50 K locations using a stratified sampling approach independent of any existing global built-up surface products. We launched a crowdsourcing campaign using Geo-Wiki ( https://www.geo-wiki.org/ ) to visually interpret this sample set for built-up surfaces using very high-resolution satellite images as a source of reference data for labelling the samples, with a minimum of five validations per sample location. Data were collected for 10 m sub-pixels in an 80 × 80 m grid to allow for geo-registration errors as well as the application of different validation modes including exact pixel matching to majority or percentage agreement. The data set presented in this paper is suitable for the validation and inter-comparison of multiple products of built-up areas.
The main prerequisite for this study is the use of forest resources corresponding to the principles of sustainable forest management. The purpose of this study is to figure out the growth ...characteristics of pine stands and their physiological response to adverse factors. The experimental material (cores) was selected from pine forests of Ukrainian Polissia using Haglöf increment borer at breast height of 1.3 m. The number of annual rings and the parameters of radial increment were found using the ImageJ software. The result was a tree-ring chronology of sample trees. Statistical analysis of the experimental data proved that the radial increment variability decreases with age, and it ranges within 0.99-2.78 mm. The average radial increment value in the data set under study is 1.79 mm. The average number of annual rings of Scots pine (Pinus sylvestris L.) trees is 80: the minimum is 61, the maximum is 92. The correlation analysis of experimental data proved that the pairwise correlation coefficients of radial increment (-0.54) and current increment by diameter (-0.53) have an inverse relationship with the age of trees, and diameter at breast height with age – a direct relationship (0.87). The developed mathematical models of the dynamics of the width of the annual ring, the diameter at breast height and the current increment by diameter allow estimating the growth characteristics of Scots pine trees throughout their life. The obtained results were compared with the growth tables of fully stocked (at a relative stocking of 1.0) stands. The adequacy test of the developed mathematical models proved the accuracy of the given patterns and is as follows: for the width dynamics of the annual ring – 0.46; the diameter at breast height – 0.78, and the percentage of current increment by diameter – 0.51. Based on standardisation of individual chronologies by calculating sensitivity coefficients, no significant physiological response was established. Accordingly, the impact of short-term stress reactions is insignificant. The maximum resistance of pine stands to adverse environmental factors is achieved at the age of 50-60 years. This study is important to evaluate the impact of climate change and other adverse factors on the growth of pine stands and forecasting the dynamics of biometric indices. The obtained results can be used by the specialists at IA “Ukrderzhlisproekt” to update biometric indices and substantiate the use of forest resources
For the first time a new method for estimation of biotic production of trees crown components are approbated. The statistical characteristics of model trees and branches, the coefficients of ...correlation and regression models are presented. The results of the study can be used to construct a regional carbon budgets.
Models of live biomass fractions of alder stands (stem wood over bark, bark, wood and bark of branches, foliage) were developed according to the methodology of the International Institute for Applied ...Systems Analysis. Tables of bioproductivity of black alder forests in Ukrainian Polissya were created based on the obtained models and yield tables for modal alder stands of vegetative origin.
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