Plant species composition and vegetation structure of Sphagnum cultivation sites

Aims

The cultivation of Sphagnum mosses in paludiculture has high potential for the use of formerly drained peatlands under wet conditions. The aim of this study was to evaluate the plant species composition and vegetation structure of Sphagnum cultivation sites in comparison with near-natural donor sites and rewetted sites without Sphagnum introduction.

Location

Central Europe, northwest Germany close to the Dutch–German border.

Methods

The treatments (rewetting with and without Sphagnum introduction) and a near-natural donor as a reference were each studied at three different sites. At each site, bryophyte and vascular plant species composition as well as parameters of vegetation structure were sampled in 40 randomly positioned plots of 25 cm × 25 cm.

Results

In addition to the highly frequent Sphagnum, several further plant species typical of bogs were introduced. At two cultivation sites, the species composition showed a high degree of similarity to the near-natural donor sites, whereas the third site was more similar to the rewetted sites without the introduction of Sphagnum biomass. Rewetted sites were species-poor in comparison with all other sites. Apart from a high cover of Sphagnum, the vegetation structure at the cultivation sites differed significantly from the near-natural donor sites.

Conclusions

Sphagnum cultivation sites can be used to grow donor material for peatland restoration and contribute to species conservation by providing substitute habitat for bog-typical and threatened plant species.     

Effects of climate warming on Sphagnum photosynthesis in peatlands depend on peat moisture and species‐specific anatomical traits

Climate change will influence plant photosynthesis by altering patterns of temperature and precipitation, including their variability and seasonality. Both effects may be important for peatlands as the carbon (C) sink potential of these ecosystems depends on the balance between plant C uptake through photosynthesis and microbial decomposition. Here, we show that the effect of climate warming on Sphagnum community photosynthesis toggles from positive to negative as the peatland goes from rainy to dry periods during summer. More particularly, we show that mechanisms of compensation among the dominant Sphagnum species (Sphagnum fallax and Sphagnum medium) stabilize the average photosynthesis and productivity of the Sphagnum community during summer despite rising temperatures and frequent droughts. While warming had a negligible effect on S. medium photosynthetic capacity (A_max) during rainy periods, A_max of S. fallax increased by 40%. On the opposite, warming exacerbated the negative effects of droughts on S. fallax with an even sharper decrease of its A_max while S. medium A_max remained unchanged. S. medium showed a remarkable resistance to droughts due to anatomical traits favouring its water holding capacity. Our results show that different phenotypic plasticity among dominant Sphagnum species allow the community to cope with rising temperatures and repeated droughts, maintaining similar photosynthesis and productivity over summer in warmed and control conditions. These results are important because they provide information on how soil water content may modulate the effects of climate warming on Sphagnum productivity in boreal peatlands. It further confirms the transitory nature of warming‐induced photosynthesis benefits in boreal systems and highlights the vulnerability of the ecosystem to excess warming and drying.     

Assessing native desert vegetation recovery in a war‐affected area using multispectral and hyperspectral imagery: a case study of the Sabah Al‐Ahmad Nature Reserve,Kuwait

The primary aim of this project was to assess vegetation changes in the Sabah Al‐Ahmad Nature Reserve, Kuwait, which is a war‐affected area following the Iraqi invasion in 1990. After the liberation in 1991, several portions of the reserve were under a restoration program. Remote sensing has been used as a tool to assess vegetation and land cover changes. We studied the feasibility of three common methods—the Mahalanobis distance (MD), maximum likelihood (ML), and support vector machine (SVM)—for classification of the multispectral imagery (Landsat) and hyperspectral (Hyperion). The reserve was also compared to the demilitarized zone (DMZ) located at Umm Nigga at the northern border of Kuwait, as it had recovered naturally, to distinguish between an autogenic recovery and a restored area. We discovered that the location was damaged during the military occupation, but a rapid recovery of the vegetation was then recorded in the reserve after the war from less than 1% measured in 1991 to 42% in 1998. Then, the vegetation cover significantly decreased in 2002 (26%) and slightly increased in 2013 (28%). We found that similar rapid increase in vegetation cover occurred in most parts of the reserve that was under the restoration program, and in the DMZ, which was naturally recovered. We concluded that remote sensing technologies are helpful tools in understanding the process of vegetation recovery as it provides information on location and timing of recovery, particularly where optimal condition exists.     

Deer do not affect short‐term rates of vegetation recovery in overwash fans on Fire Island after Hurricane Sandy

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