Citizen science is becoming increasingly popular as a format in environmental and sustainability education. Citizen science not only allows researchers to gather large amounts of biodiversity-related data, it also has the potential to engage the public in biodiversity research. Numerous citizen science projects have emerged that assume that participation in the project affects participants’ knowledge, attitudes, and behavior. We investigated what evidence really exists about the outcomes of biodiversity citizen science projects on the side of the individual participants. For this purpose, we conducted a systematic review of peer-reviewed research articles published up to and including 2017. We found evidence for various individual participant outcomes. The outcome reported most often was a gain in knowledge. Other outcomes, found in several articles, referred to changes in behavior or attitudes. Outcomes reported less often were new skills, increased self-efficacy and interest, and a variety of other personal outcomes. We discuss the research design and methods used in the reviewed studies und formulate specific recommendations for future research. We conclude that citizen science is a promising option for environmental and sustainability education focusing on biodiversity. Partnerships between natural and social scientists in the design and evaluation of projects would allow future biodiversity citizen science projects to utilize their full educational potential.

Citizen science (CS) is regarded as a promising format in environmental and sustainability education as well as in science education. CS projects often assume that participation in the project influences, for example, participants' knowledge or behaviour. We investigated whether and to what extent biodiversity citizen science (BDCS) projects, from the participants' self‐reported perspective, achieve the following six participant outcomes: (a) content, process and nature of science knowledge, (b) skills of science inquiry, (c) self‐efficacy for science and the environment, (d) interest in science and the environment, (e) motivation for science and the environment and (f) behaviour towards the environment. For this purpose, we conducted an online survey of 1,160 CS participants across 63 BDCS projects in Europe, Australia and New Zealand. Our survey was aimed at adults participating in CS voluntarily. Survey respondents reported positive changes in all six categories. The most notable result across projects was that self‐reported increases in knowledge, self‐efficacy, interest and motivation were found to be more pronounced when regarding the environment rather than science. Perceived gains in data collection skills were reported to be higher than gains in skills not directly connected to data collection. Reported behaviour changes primarily concerned communication activities, to a lesser degree also gardening activities, and finally more general environmental behaviour. In addition to these six participant outcomes, respondents mentioned a variety of other positive and negative outcomes, for example, health and well‐being, enjoyment, a sense of satisfaction, an increased connection to people and nature but also a more pessimistic view regarding the future of the environment. We conclude that BDCS projects could have a high potential for environmental and sustainability education as well as science education. Further research should investigate individual participant outcomes in more depth and should focus on the factors that influence these participant outcomes. Moreover, exploring the perspectives of both project participants and project coordinators would be valuable. In this way, it would be possible to improve the development and design of CS projects. As a result, BDCS projects could more effectively achieve outcomes for the participants, for science and for biodiversity. A freePlain Language Summarycan be found within the Supporting Information of this article.

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open, and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e., berry mass, number of fruits, and fruit density [kg/ha], among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), North America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001–2005 (21 studies), 2006–2010 (40), 2011–2015 (88), and 2016–2020 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non‐commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY‐NC‐SA).

The spatial distribution of predators and their prey is affected by their joint use of space. While the formation of such spatial patterns may be driven by density‐dependent and ‐independent factors our knowledge on the contribution of different land‐use activities on the formation of spatial patterns between predators and prey remains very limited. Agriculture is one of the most prevailing land‐use activities with strong effects on invertebrate densities and structural habitat conditions. Here, we used replicated conventionally and organically managed winter wheat fields to investigate the effects of agricultural land‐use on the spatial patterns of generalist predators and decomposer prey. We then identified the explanatory power of density‐dependent (prey and predator activity density) and density‐independent (vegetation structure) predictors for the observed spatial patterns. Generalist predators were regularly distributed only in conventionally managed fields and this pattern intensified with decreasing Collembola prey availability and increasing spider activity density. Segregation between carabid and spider predators was strongest in fields with lowest wheat plant height, suggesting more intense intraguild interactions in structurally less complex habitats. Collembola were aggregated independent of management and aggregation was strongest in fields with highest Collembola and carabid activity density. Spiders and Collembola prey were associated, but higher aphid densities under conventional management weakened or interrupted this spatial relationship. We conclude that active control of crop plant physiognomy by growth hormones and herbicides in conventionally managed fields promotes predator–predator segregation and that a high availability of aphid prey seems to decouple predator–Collembola prey associations. Our results emphasise the need for a more mechanistic understanding of the effects of land‐use on the formation of spatial patterns and species interactions, especially under scenarios of environmental change and an ongoing loss of biodiversity.