Temporal trends in pollination of the Asteraceae family.
| Reference (publication date) | Region (number of sites) | Study period | Methodology | Trend identification technique | PIn (grains per cubic meter of air per decade and significance) | PSS (days per decade and significance) | PSD (days per decade and significance) |
|---|---|---|---|---|---|---|---|
| [18] (2014) | Europe (13) | 1990–2009 | Hirst-type | Linear regression | – in 8 sites of 10, * in Derby, ** in Strasbourg, *** in Leiden | – in 6 sites of 10 (** in Derby) | + (ns) except in Prague |
| Artemisia | |||||||
| [25] (2018) | Brussels (1) | 1982–2015 | Hirst-type | Local regression method (LOESS) | – | ||
| [26] (2003) | Switzerland (1) | 1979–1999 | Hirst-type | Linear regression | + (ns) | – (8.1; *) | No trend |
| [27] (2025) | Texas, USA (1) | 2009–2023 | Hirst-type | Least square regression | – (0.5; ***) | ||
| [28] (2021) | Benelux (5) | 1981–2020 | Hirst-type | Linear regression | – (*) in 3 sites of 5 | – in all sites; * in only 1 | + in all sites; * in 3 out of 5 |
| [30] (2014) | Catalonia (8) | 1994–2011 | Hirst-type | Linear regression + non-parametric test | – | ||
| [32] (2000) | Basel (1) | 1969–1998 | Hirst-type | Linear regression | – (ns) | ||
| [36] (2016) | Spain (12) | 1994–2013 | Hirst-type | Linear regression | + at 8 sites out of 12 | ||
| [37] (2021) | Basel (1) | 1969–2018 | Hirst-type | Linear regression | – (~29; ***) | ||
| [38] (2021) | Switzerland (14) | 1990–2020 | Hirst-type | Linear regression + LOESS | – (*) | ||
| [40] (2018) | Brussels (1) | 1982–2015 | Hirst-type | Linear regression + Mann-Kendall test | – (***) | – (ns) | + |
| [42] (2011) | Germany (10) | 1988–2009 | Hirst-type | Linear regression + Mann-Kendall test | – in NW and S | + in S (~9) | + in NE and NW |
| [44] (2016) | Stockholm (1) | 1973–2013 | Hirst-type | Linear regression | No trend | – (~3.0; *) | + (~6.6; ***) |
| [45] (2011) | S Poland (1) | 1991–2008 | Hirst-type | Linear regression | + (*) | No trend | No trend |
| [50] (2003) | W Europe (5) | 1968–2001 (partly) | Hirst-type | Linear regression | – in Brussels and Derby, + in the 3 other sites; * in 1 site, ** in the 4 others | ||
| [51] (2024) | NE Italy (20) | 2006–2022 | Hirst-type | Theil-Sen estimator | – (26) | No trend | + (5.0) |
| [55] (2015) | USA (50) | 1994–2010 | Unspecified | Linear regression | – in the NE (30.3; *) | – in the NE (7.4; *) | + in the NE (5.9; *) |
| [56] (2012) | Europe (97) | 1977–2009 (partially) | Hirst-type | Linear regression | – (5; ***) | ||
| [57] (2020) | N & Central Italy (9) | 2000–2016 | Hirst-type | Non-parametric Mann-Kendall test | No trend | + | No trend |
| [73] (2002) | W of the NL (1) | 1969–2000 | Hirst-type | Linear regression | – (3.75) | ||
| 2000s–2090s | Modelling | Unspecified | – (1.5) | ||||
| [81] (2007) | Thessaloniki (1) | 1987–2005 | Hirst-type | Linear regression | + (~2) | No trend | No trend |
| [83] (2002) | Central Italy (1) | 1982–2001 | Hirst-type | Linear regression | – (1.5; ns) | No trend | No trend |
| [85] (2021) | Slovakia (1) | 2002–2019 | Hirst-type | Linear regression + Mann-Kendall test | – | – | |
| [119] (2014) | W Poland (1) | 1996–2011 | Hirst-type | Mann-Kendall test + Sen’s slope estimator | – (813; *) | – (7.5; **) | No trend |
| [121] (2000) | NW Italy (1) | 1981–1997 | Hirst-type | Linear regression | No trend | ||
| [127] (2013) | SE Spain (1) | 1992–2011 | Hirst-type | Linear regression | – (~38; ns) | + (~2; ns) | – (~6.3; ns) |
| [129] (2020) | N Italy (2) | 1995–2019 | Hirst-type | Linear regression + Mann-Kendall test + Sen’s estimate + Pettitt test | – (ns or *** until end of August), then + (** or ***) | ||
| Ambrosia | |||||||
| [26] (2003) | Switzerland (1) | 1979–1999 | Hirst-type | Linear regression | + (ns) | – (9.5; *) | No trend |
| [27] (2025) | Texas, USA (1) | 2009–2023 | Hirst-type | Least square regression | + (5.2; ***) | ||
| [37] (2021) | Basel (1) | 1969–2018 | Hirst-type | Linear regression | – (ns) | ||
| [38] (2021) | Switzerland (14) | 1990–2020 | Hirst-type | Linear regression + LOESS | No trend | ||
| [45] (2011) | S Poland (1) | 1991–2008 | Hirst-type | Linear regression | No trend | No trend | |
| [51] (2024) | NE Italy (20) | 2006–2022 | Hirst-type | Theil-Sen estimator | No trend | + (4.5) | – (4.3) |
| [55] (2015) | USA (50) | 1994–2010 | Unspecified | Linear regression | + in the S (58.8; *) and the NE; – in the NW Central (23.9; *) | – (1.8 to 1.9 in the NE; *); ns elsewhere | + in the S (1.5); ns elsewhere |
| [56] (2012) | Europe (97) | 1977–2009 (partially) | Hirst-type | Linear regression | + (9; **) | ||
| [59] (2021) | Georgia, USA (1) | 1992–2018 | Rotorod | Linear regression | No trend | – (0.9) | + (1.2) |
| [62] (2025) | N Italy (1) | 1997–2023 | Hirst-type | Linear regression | + (ns) | + (ns) | – (8.7; ns) |
| [81] (2007) | Thessaloniki (1) | 1987–2005 | Hirst-type | Linear regression | – (~3) | ||
| [90] (2024) | N Italy (1) | 1989–2018 | Hirst-type | Linear regression + Mann-Kendall test | + (**) | ||
| [92] (2021) | Oklahoma, USA (1) | 1996–2020 | Hirst-type | Linear regression | – (~2,700; ***) | + (ns) | + (ns) |
| [110] (2024) | Slovakia (2) | 2002–2022 | Hirst-type | Linear regression + Mann-Kendall test + Theil-Sen estimator | + (ns) | – (ns) | + (***) at 1 site out of 2 |
| [121] (2000) | NW Italy (1) | 1981–1997 | Hirst-type | Linear regression | + from 1989 (**) | ||
| [131] (2002) | Oklahoma, USA | Experiment | + (+84% for A. psilostachya with a warming of 1.2°C) | ||||
| [132] (2014) | Oklahoma, USA (1) | 1987–2011 | Hirst-type | – (**) | + (ns) | + (ns) | |
| [134] (2011) | Central North America (10) | 1995–2009 | Mostly Hirst-type, but also Rotorod and Durham | No trend in the S, increasingly + northwards (up to 18.0) | |||
| [135] (2015)[136] (2017) | Europe | From 1986–2005 to 2041–2060 | Model | + (~4 times more) | + | ||
| [137] (2018) | Missouri, USA (1) | 1997–2017 | Hirst-type | – | + | ||
The grey backgrounds correspond to studies that have made projections about the future. +: trend towards increased pollen concentration (PIn), earlier onset of pollination (PSS), or longer pollen season (PSD); –: trend towards decreased pollen concentration (PIn), later onset of pollination (PSS), or shorter pollen season (PSD); *: p < 0.05; **: p < 0.01; ***: p < 0.001. PIn: pollen integral; PSS: pollen season start date; PSD: pollen season duration; LOESS: locally estimated scatterplot smoothing; ns: non-significant; NW: northwest; S: south; NE: northeast; W: west; N: north; NL: Netherlands; SE: southeast.