Patterns of reverse correlation are no exception and are also observed in other countries, such as Germany . This may both be due to purely economic reasoning and psychological factors related to the different attitudes of farmers, which limit the choices available to them in terms of how to manage their farms . Particularly noteworthy areas are those with the greatest gap between the indicators that were analysed, i.e. with a high suitability and low uptake of funds, and vice versa. These areas – as divided into LAU2 units – have been assigned to the extreme classes . A positive ISFOFS value, which is indicative of a high uptake of funds relative to the potential, is observable for 18 LAU2 units, located mainly in the Zachodniopomorskie region. The reverse situation – absence of payments despite a very high score for the potential is noticeable for 40 LAU2 units, with slightly larger clusters formed in the south-eastern part of the country and in the east of the Pomorskie Voivodeship. Spatial discrepancies are also revealed by the overlapping of HH, LL clusters and units where no OF payments were recorded at all . Overall, 68 units were classified as HH clusters in which not a single application for OF co-funding was submitted, and two municipalities were ranked as HH clusters for IUOFF and LL for IESAOF. The completed research proves that there is a need to enhance territorial targeting of support for organic farming in order to increase the correspondence between the uptake of funds and natural conditions in a given area. The results of the analysis confirm the conclusions of studies conducted, for example, by B` arberi et al. , nft growing system according to which there is a tendency towards spatial segregation between highly specialised, productive areas and areas with small-scale,low-input farming.

In terms of the intensity of agricultural production, it has been found that the share of agri-environmental measures is low in regions of intensive production, which confirms the results of the research by FruehMueller et al. . At the same time, it shows similarities with the results in other countries . Nevertheless, research highlights a certain specificity in Poland. The highest activity in the implementation of the agrienvironmental measures is demonstrated by the areas with the largest average farm area . However, despite the larger acreage, these farms are not generally engaged in highly specialised and intensive production. The yields they achieve are at an average level and in some areas even more extensive forms of use can be found. If the overall effectiveness of organic farming for enhancing biodiversity is to be increased, strategies are needed to optimise the desired lines of development for OF. In this respect, high hopes are attache to the new EU policy, known as the European Green Deal , which is aimed at boosting the role of environment al activities. The policy significantly enhances the role and prominence of organic farming. The key objective is to increase the output and consumption of organic products, inter alia by having 25 percent of farmland used for organic farming by 2030 and substantially expanding organic aquaculture. Based on the findings of the study, it is postulatem that work on the preparation of action plans dedicated to organic production should take into account the disparities between regions in terms of their natural potential for the development of modern, effective organic farming. Properly addressed support will enable the ambitious goals set by the European Commission and the assumptions resulting from the EGD to be achieved. As Peter Duelli states, ‘when the aim is species conservation for their intrinsic, aesthetic, cultural or traditional values, it can be called practicing ‘agriculture for biodiversity’. When on the other hand, the policy aims are related to the improvement of the functioning of the agroecosystem , it can be called improving ‘biodiversity for agriculture’ .

The trends in the absorption of funds aimed at the development of OF highlight the great importance of spatial interrelationships and neighbourhood, which is confirmed by the overall Moran’s I spatial correlation coefficient. The values of the variable studied determine and at the same time are determined by the values of the same in Fig. 4. IESAOF and IUOFF scatter plot. neighbouring locations. These spatial relationships lead to a spatial grouping of units with similar values of the variable . It has been shown that agglomeration effects are characteristic not only of spatial structural changes in agriculture but also of the uptake of environmental CAP funds. One difficulty in identifying the spatial links between the targeting and amount of support for organic farming and the natural potential follows from, among other factors, the fact that environmental and managerial processes are not correlated , mainly in terms of the appropriate orientation of payments under the OF Measure , or spatial scale mismatches , which in turn reduces the effectiveness of agri-environmental policies. This is confirmed by the results of research on OF conducted in Poland. In order to improve the rationality of the use of organic farming funds so this corresponds to the environmental potential of areas, the measures applied should include a regional component, as is the case in Germany, where each Land has a specific autonomy in the making of development policy on OF based on its own specific conditions . Further studies should explore whether the results obtained also apply to other EU member states that differ from Poland in terms of their environmental characteristics and the organic farming schemes that are being implemented. This is also addressed by the European Commission.

The EU’s Farm to Fork Strategy and the Biodiversity Strategy set ambitious goals for the agricultural sector in order to ensure that it is prepared to adapt to the objectives of the European Green Deal. Organic farming will be a key element in the transition to a more sustainable food system and in better protection of biodiversity. With the use of appropriate policies and the right legal framework, the European Commission is tasked with supporting the organic farming sector in achieving the goals it set for the development of organic farming.Wetland is one of the most important landscapes and provides essential ecosystem services and functions, such as supporting biodiversity, improving water quality, providing habitat and mitigating the effects of drought and flooding . However, more than half of wetlands globally have been lost due to development of economies during the past century . Agricultural activity is widely recognized as a key driver of natural wetland loss and it undermines the capacity of natural wetlands to deliver ecosystem services in many parts of the world . Approximately 60% of China’s and 85.4% of Northeast China’s natural wetlands have been lost due to agricultural encroachment for gain production . When large areas of wetlands are drained for agriculture, the ecosystem services these wetlands performed are lost . There is an urgent need to restore wetlands, especially to recover their functions and services. It plays a crucial role in maintaining plant and genetic diversities, supplying potential resource for ecological restoration, determining future vegetation composition and maintaining ecosystem resilience under disturbances.Recently, researches about restoration potential of wetland vegetation have been explored in North America, Europe, as well as Northeast China, and proved a low probability of reaching the original prefarming status due to the lack of seeds.The potential of natural restoration using soil seed banks closely relates to wetland type, the duration of drainage and farming, and the longevity of seeds.Whether vegetation will naturally reestablish after agricultural reclamation depends on the capability and validity of seeds in soils . Therefore, it is necessary to explore the availability of soil seed bank and identify the limitative factors for wetland restoration, particularly after disturbances.

Soil salinization has become a widespread threat to wetlands, such as leading to wetland degradation, altering ecosystem processes and landscapes dynamics, and impacting valuable ecosystem functions and services . Seed germination and seedling establishment are influenced by both seed traits and environmental factors including salinity . Excessive salt in the soil not only constrains the growth and reproduction of wetland species, but also the seed germination . Many studies have found that species had various tolerance ranges of salinity and different strategies to avoid risk . But still little is known about the response of soil seed banks to salinity in salt-affected inland marshes. The Songnen Plain, located in the confluence of the Songhua River and Nenjiang River, is the largest component of the Northeast Plain of China. Wetlands and lakes are widely distributed in the Songnen Plain,vertical hydroponic nft system which has become vital habitats for rare birds because of flat terrain, abundant water and rich biodiversity. At the same time, the Songnen Plain has large areas of agricultural lands and is a major gain producing area of China. However, the development of agriculture destroyed wetlands, resulting in soil salinization and loss of ecosystem functions. Recently, restorative engineering has been conducted to restore wetland hydrology and reduce wetland degradation, but the vegetation of above ground has not been self-recovered in the restored wetlands. Our study aimed to answer the following questions: How do soil seed banks change during farming in the two dominated plant community types ? What is the value of soil seed banks in vegetation restoration? Does saline-alkaline stress influence the seed bank germination and wetland restoration potential? The study was conducted at the Momoge National Natural Reserve , which is located in the Songnen Plain in the northeast of China. The region has a temperate continental monsoon climate, with a mean annual temperature of 4.4 ◦C and a mean annual precipitation of 380 mm. The dominant species of plant communities in natural wetlands in this region are tussock-forming Carex and Phragmites australias. The sites are facing challenge of soil salinization because of climate change and human activity. Large area of wetlands has been cultivated in the Songnen Plain since the 1950s to guarantee stable gain production and economic development. The construction of agricultural water conservancy facilities destroyed hydrological cycle, altered the soil–water environment of wetlands, and declined ecosystem diversity and functions of wetlands .

We chose two types of plant community in wetlands and their adjacent farmed fields . These farmlands were converted from natural wetlands and had similar soil physicochemical properties and vegetation. These farmed fields were drained and cultivated for soybean over 20 years. The soil seed bank was sampled after thawing of soil water in April 2020. At each study site, five quadrats were randomly distributed. Then, surface soil of each quadrat was collected to guarantee the highest density of viable seeds. Soil samples were mixed for each site and placed in plastic bags. Species composition of the above ground plant community was surveyed in August 2020. Ten quadrates were randomly chosen in each site to determine the species richness and abundance, the height and coverage of individuals per species and total cover of above ground vegetation. The seedling germination experiment was conducted in a greenhouse to determine the size and composition of soil seed banks after reclamation and the potential of natural restoration of wetlands. Soil samples from each site were removed debris and root propagules by sieving with a 2 cm screen, and then divided into 20 sub-samples to set 5 replicates for each treatment. Each sub-sample was spread as an even layer, 1 cm thick, and placed on 8 cm layer of washed vermiculite in pots . The pots were placed in four tanks . We designed moist and flooding treatments to satisfy the water requirements of germination. Two levels of saline-alkaline conditions were used to determine the response of soil seed banks to salinity stress. The control treatment was irrigated by freshwater, and saline-alkaline treatment was irrigated by NaHCO3 solution to keep an electrical conductivity of 1.0 dS/m, which was matched with the average of salinity measured in lakes in the Songnen Plain . The newly seedlings germinated from soil samples were identified, counted and removed from the pots.