1. Heterostyly is a genetically determined floral polymorphism of style length promoting outcrossing between individuals of different morphs, which usually coexist within populations at equal frequencies. Loss in the area and connectivity of suitable habitats may cause deviations from the expected equal morph frequencies. However, there is a need to evaluate the generality of this pattern at larger spatial extents and to identify possible underlying mechanisms.
2. A citizen‐science approach was used to study morph frequencies in populations of the heterostylous grassland plant Primula veris across Estonia. We developed an online platform to facilitate an easy upload of the data. We examined the effect of the following variables in the surroundings of the study populations reflecting the landscape context on the deviation of morph ratios: (a) semi‐natural grasslands, (b) forests and shrubs, (c) human population density and (d) a proxy for plant population size.
3. The citizen‐science approach provided unprecedented density of data from 1,700 localities. Nearly half of these observations, which were maintained for further analysis after data filtering, included over 62,000 short‐styled morphs and about 54,000 long‐styled morphs. Small populations were characterized by higher overall deviation of morph ratios from isoplethy (equal morph ratio). Deviation increased in semi‐natural grasslands located in regions with high human population density.
4. The significant effect of human population density and plant population size on deviations of morph frequencies suggests the role of stochastic demographic effects of habitat fragmentation on morph ratios. Overall lower proportion of long‐styled morphs indicates that partial intra‐morph compatibility shown in long‐styled morphs may lead to higher inbreeding and related decline in fitness and abundance.
5. Synthesis. Citizen‐science data about the morph type of Primula veris across Estonia obtained with the help of thousands of people demonstrates that in addition to plant population size, landscape context may affect plant reproductive traits, such as heterostyly. Larger population size of P. veris can help to buffer against random fluctuations in this trait. Increasing impact of human activities may have a negative impact on both small and large populations. The exact underlying mechanisms of the prevalence of one morph over the other, however, pose novel questions for further research.

中文翻译：

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景观背景和植物种群数量影响异质报春花Veris的形态频率-全国公民科学运动的结果

1. 异质性是由基因确定的花序长度的花卉多态性，其促进不同形态个体之间的异型杂交，这种异型杂交通常以相同的频率共存于种群中。面积和合适栖息地连通性的丧失可能导致与预期的相等变态频率偏离。但是，需要在更大的空间范围内评估这种模式的普遍性，并确定可能的潜在机制。
2. 一种公民科学方法被用来研究爱沙尼亚整个草地上异质草植物报春花的种群中的变态频率。我们开发了一个在线平台，以方便轻松地上传数据。我们研究了以下变量在研究人群周围环境中的影响，这些变量反映了景观背景对形态比率的偏离：（a）半天然草地，（b）森林和灌木，（c）人口密度和（d ）代表植物种群数量。
3. 公民科学方法提供了来自1,700个地方的前所未有的数据密度。这些观察结果中有将近一半在数据过滤后保留以进行进一步分析，包括超过62,000个短样式和大约54,000个长样式。小种群的特征在于形态比与等体积（等形态比）的总体偏差较高。在人口密度高的地区的半天然草原，偏差增加。
4. 人类种群密度和植物种群大小对形态频率偏差的显着影响表明，生境破碎化的随机人口统计学效应对形态比率的作用。长样式的总体比例较低，这表明长样式中显示的部分内部变形相容性可能导致近亲繁殖的增加以及适应度和丰度的下降。
5. 综合。在成千上万的人的帮助下获得的关于爱沙尼亚报春花变型类型的公民科学数据表明，除了植物种群数量外，景观背景还可能影响植物的生殖性状，例如杂种优势。更大的P. veris种群规模可以帮助缓解该性状的随机波动。人类活动的影响越来越大，可能对大大小小的人口都产生不利影响。然而，一种变体普遍存在的确切潜在机制为进一步研究提出了新的问题。