European regional assessment: Data Deficient (DD)
EU 27 regional assessment: Data Deficient (DD)

Gladiolus palustris is a European endemic that is subject to several threats to its habitat and the species directly such as the modification of cultivation practices, the management of water systems and drainage, pollution, and collection. It is classed as Data Deficient as there are declines everywhere as evidenced in the species being marked as threatened in several national Red List. There is no information on whether the species has strong and abundant populations anywhere. More information on the current population size, trend and the overall rate of decline is needed to review whether it would qualify for threatened under Criterion A.

This plant is endemic to Europe. North of the Alps, it ranges from eastern France and the Alsace, Germany, Czech Republic, Slovakia, Poland eastwards with fragmented patches in Belarus, Ukraine and Russia. South of the Alps, it extends from the Appenines in Italy to eastern Austria and Hungary where it extends to western Bulgaria and Albania in the Balkans (Käsermann and Moser 1999, Euro+Med Plantbase 2006-2010).

The following population sizes have been determined in some countries (Commission of the European Communities 2009):

• Germany: 89 localities, stable trend
  
• Hungary: 52,000 - 55,000 individuals, increasing trend
  
• Poland: 4-8 individuals, declining trend
  
• Slovakia: one locality, stable trend
  
• Slovenia: 7 grids, declining trends
  

In Bulgaria, there are five localities with recent data from two localities and the other three localities have no confirmed data since early 1900 because of identification problems. In Czech Republic, there are now 323 flowering species, 98 in 2009, at one locality. The population trend is unknown. In Italy, it is found at more than 90 localities with a stable population trend.

In France, it occurs at 33 localities in 24 communes with more than 25,000 individuals estimated. The species is declining because of mowing and habitat drainage. In Serbia, it is estimated to be Vulnerable (Stevanović pers. comm. 2010). In Switzerland, a slight to moderate population decline has been noted over the last 20 years.

In Ukraine, only one locality was found near Dmitrivka village, Novgorod-Siverskij district, Chernigivska region. This finding dates to 1912 and is now probably extinct. One locality of Gladiolus palustris was found in Belarus in Duroviesy village, in Mogylov region in the 19th century, and is now extinct.

In Slovakia its occurrence was confirmed in only three localities on the Záhorská nížina Lowland: in Abrod NNR, near Sološnica and between Gbely-Adamov and Holíč. In the past the species was recorded in about ten localities in the Záhorská nížina Lowland and on the Malé Karpaty Mts foothills; the other localities were in central Slovakia (Pukanec, Poľana massif, Pohronie region) and there is a dubious record from the surroundings of Poprad. In the remaining three localities on the Záhorská nížina Lowland approximately 1,000, 30 and three individuals were recorded respectively. The size of subpopulations and their number have rapidly decreased over the last decades and the species is now in danger of extinction (Mereďa and Hodálová 2011).

In Poland the species was reported in 20 localities, mainly in the 19th century. Since 2000 it has been confirmed only in the locality in the Sudety Foothills (Kaźmierczakowa and Zarzycki 2001). There are now 20 individuals, with a declining trend (Piękoś-Mirkowa and Mirek 2008).

Gladiolus palustris is found in coniferous, mainly pine forests (Erico-Pinion) (Klotz et al. 2002) and wooded wet meadows. It prefers periodically wet meadows but is tolerant to dryness. If the habitat is not periodically wet the populations decrease due to competition from other plants (Käsermann and Moser 1999). It grows on calcareous, moderately humic and nutrient-poorer soils. The species occurs also on steppe-character meadows and in oak groves with moor grass (Molinia) (Mereďa and Hodálová 2011).

This plant grows in the following Habitats Directive listed habitats (Commission of the European Communities 2009):

• 62A0 Eastern sub-Mediterranean dry grasslands (Scorzoneratalia villosae)
• 6260 Pannonic sand steppes
• 6410 Molinia meadows on calcareous, peaty or clayey-silt-laden soils (Molinion caeruleae)
• 6440 Alluvial meadows of river valleys of the Cnidion dubii
• 91M0 Pannonian-Balkanic turkey oak-sessile oak forests

The main threat is the modification of cultivation practices such as mowing, grazing, abandonment of pastoral systems, forest planting. This often leads to a change in vegetation and competition for Gladiolus palustris. The management of water systems and drainage or canalization have negative impacts and are another important threat. Conversion of its meadow habitat into arable land causes habitat loss. Collection leads to further population declines. Pollution from the use of pesticides and fertilizers as well as eutrophication affect the species. Locally, threats such as aquaculture, roads and railway lines, exist.

The plants were dug up in the past for use in horticulture. The bulb was believed to provide protection against injuries and was therefore harvested which might have led to some extinctions (Käsermann and Moser 1999).

It is possible that the plant is still cut or dug up as it is a very beautiful plant.

Gladiolus palustris is listed on Annex II of the Habitats Directive.
The following national listings and conservation measures are in place:

• Belarus: listed as Extinct
• Bulgaria: Data Deficient, the two known localities with recent data are in Natura 2000 sites
• Croatia: listed as Data Deficient
• Czech Republic: listed as Critically Endangered and protected in the strongest category, the one locality is a site of community interest and in a protected area
• France: nationally protected, conservation actions are taking place on 12 localities (no precise data)
• Germany: classed as Endangered (level 2) and under national protection
• Hungary: classed as Endangered
• Italy: it is protected at regional level
• Poland: listed as Critically Endangered and strictly protected at national level; the only population existing in Poland is situated in a nature reserve (Łąka Sulistrowicka)
• Switzerland: classed as Endangered; reintroductions have taken place
• Slovakia: listed as Critically Endangered; the species occurs in one Natura 2000 site, covering 80% of its localities (Mereďa and Hodálová 2011).
• Ukraine: listed as Endangered