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Impacts of Environmental Heterogeneity on Distribution Pattern of Moss Crust Patches in Temperate Desert in Central Asia

Ji X.-H., Pang S.-Q., Zheng Q.

Polish Journal of Ecology

2018

Vol. 66, nr 2

83--101

Moss crusts are the highest developmental stage of biological crusts in arid and semiarid ecosystems worldwide. Under natural conditions, elementary functional units of moss crusts are patches. However, to date, the quantitative features, distribution pattern, ecological effect and relationship with environmental factors of moss patches in desert ecosystems remain unclear. In this study, 3303 moss patches in 22 plots and relevant environmental variables were investigated and quantified in the Gurbantunggut Desert, China. Thirty-six patch classes were defined. Moss crusts accounted on average for 11.7% of the plot area, and the mean moss patch area was 23.4 cm2. Small patches dominated, indicating a serious fragmentation of moss crusts. Significant density-dependent effects between patch density and size, humped relationships between patch size and moss plant density, and soil water content under moss patches were observed. The overall distribution of moss crusts showed a tendency of moss patch size and moss plant density decreasing from the southeastern part of the desert to the northwestern part, while moss patch density showed the opposite trend. Pearson's correlation analysis and nonmetric multidimensional scaling analysis consistently demonstrated that the distributions of moss patches were dominantly influenced by non-moss crust coverage, sand particle size, latitude, mean annual precipitation (MAP) and mean annual temperature. Of these parameters, fine sand, high MAP and low latitude were beneficial to the development of moss crusts. Consequently, the factors influencing the distribution pattern of moss crusts are complex and contain the soil factor, current climatic conditions and natural and human disturbances.

Ecosystem services of extensive wet grasslands. Wielkopolska region (Poland) case study

Borysiak J.

Ekonomia i Środowisko

2012

nr 2

136--152

Określono ekosystemowe świadczenia dwóch typów mikrokrajobrazów z seminaturalnymi łąkami z Calthion, a zarazem z bogactwem biocenoz naturalnych. Są one powiązane z ekstensywnymi (tradycyjnymi) formami użytkowania gruntów rolnych. W identyfikacji świadczeń ekosystemowych zastosowano system przedstawiony w Millennium Ecosystem Assessment, zmodyfikowany przez K. J. Wallace. Modyfikacja ta jest wynikiem krytycznego ustosunkowania się jej autora do konstrukcji powszechnie stosowanego systemu MA, rodzącego poważne problemy efektywnego zarządzania obszarami stanowiącymi mozaikę gruntów rolnych powierzchniowo zdominowanych przez antropogeniczne biocenozy synantropijne segetalne i ruderalne oraz geoekosystemów naturalnych. Wskazano zagrożenia świadczeń ekosystemowych związane z dynamicznym, gospodarczym rozwojem Wielkopolski. Omówiono jeden ze sposobów przeciwdziałania zagrożeniom świadczeń ekosystemowych w sektorze rolnictwa, jakim jest Program Rolno-Środowiskowy objęty Programem Rozwoju Obszarów Wiejskich na lata 2007-2013.

This article responds to a clarion of the MA2 . Its aim was to determine ecosystem services served by vegetation cover of permanent meadows and permanent pastures. This has been accomplished through an analysis of two types of microlandscapes that are representative for natural conditions of Wielkopolska and widespread in this region. These micro landscapes are characterised by the surface dominance of seminatural wet Calthion meadows. Both types are connected with the extensive forms of grassland use. Due to these forms, mosaic arrangements of agricultural lands and natural ecosystems have developed (historically) and survived up to the present day. Such areas are characterised by high biodiversity, however, exposed to threat from the intensification of agricultural production. In Europe, they are regarded as disappearing P. Harrison et al.5 . On account of their natural-seminatural character, they are considered by some scientists as hot spots of multiple delivery of ecosystem services (e.g. S. Lavorel et al.6 ). The analysed microlandscapes differ significantly one from the other in terms of biotic and abiotic characteristics, but, generally, they provide the same categories of ecosystem services. However, they differ in these ecosystem services that depend on the character of their flora and phytocoenotic structure of vegetation. Both types of microlandscapes are connected with the Natura 2000 habitat code *91E0, occurring in ecological corridors of river valleys.