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Plant Traits Response to Grazing Exclusion by Fencing Assessed via Multiple Classification Approach : A Case from a Subalpine Meadow

Li Wen Jin, Liu Shuang Shuang, Li Jin Hua, Zhang Ru Lan, Rang Ka Zhuo Cai, Zhou Hua Kun, Yao Bu Qing, Wan Jun Feng

Polish Journal of Ecology

2019

Vol. 67, nr 1

33--52

Using multiple classification approach to examine plant traits response to grazing and fencing (as without access to grazing) is rare. Here we used multiple classification approach to examine plant diversity, productivity and species traits response to grazing and fencing over a three-year period on the eastern part of the Qing-Hai Tibetan Plateau. The results showed that most common species response to the fence was poorly noticeable. The fencing meadows compared to those under long-term free grazing are characterized by significantly higher total species richness, but species richness declined with sampling years gradually, regardless of grazing or fencing. The correlation showed that species richness was negatively associated with mean annual temperature significantly, suggesting that abiotic factors (e.g. annual temperature) could also play important roles in driving species richness in this subalpine meadow. Total aboveground biomass was not associated with mean annual temperature and rainfall. The fencing meadow demonstrated higher community aboveground biomass relative to the grazing ones, especially the abundance of legume and graminoids increased, while the proportions of sedge decreased, suggested that grazing disturbance favours the increase of reproductive success of sedge (e.g. Kobresia humilis) in this subalpine meadow. Growth form-based analyses combined with canopy height categories should be recommended to reveal general rules and mechanisms relating to grazing.

Phytoremediation of nitroglycerin in smokeless powders

Asbaghi N., Pichtel J.

Environmental Biotechnology

2012

Vol. 8, No. 2

45--54

The reported study evaluated the feasibility of rhizosphereenhanced phytoremediation in the removal of nitroglycerin (NG), as applied in commercial smokeless powder (SP), from soil. Double base smokeless powder was applied to soil mesocosms at rates of 0, 1, 5 and 10% (w/w). The mesocosms were seeded with oats (Avena sativa) or planted with live sedge plants (Carex vulpinoidea). Composted biosolids (20% w/w) were used as a soil treatment. Mesocosms were sampled at 7, 14, 30, and 60 days after initial planting. Determination of residual soil NG was performed using gas chromatography with an electron capture detector. Both plant species were capable of modest NG uptake (146.0 and 87.5mg·kg-1 for sedge and oat, respectively at the 10% SP rate). Only modest quantities of NG removal were accounted for by abiotic processes such as soil sorption. Soil bacterial numbers remained relatively constant regardless of rate of SP application. Microbial activity in the plant rhizosphere was concluded to be the major contributor to NG solubilization and decomposition. Addition of composted biosolids to soil imparted a positive effect in NG decomposition and/or removal from soil. Additional study is needed to determine long-term decomposition of smokeless powder and subsequent NG reactions in soil.

Seasonal changes in the number of some physiological groups of heterotrophic bacteria in water, soil and plants of the wetlands near Olsztyn

Korzeniewska E., Brzozowska R., Czechowska K., Filipkowska Z., Niewolak S.

Archiwum Ochrony Środowiska

2007

Vol. 33, no. 4

39-51

Counts of heterotrophie bacteria and some physiological groups of those microorganisms (amylolytic, lipolytic, protcolytic, cascolytic) were studied in water, soil and on sedge plants (Carex acutiformis Ehrb.) in one of larger wetlands near the forester's lodge Stary Dwór, near Olsztyn. The total count of heterotrophie bacteria in the water from the wetland did not overcome 2.3 x 10^3 CFU cm^3; on plants the respective counts were 3.4 x 10^9 CFU GDW^-1on submerged parts and 1.6 x 10^9 CFU GDW^-1on aerial leaves. In the soil and on the surface of older roots the counts of heterotrophie bacteria were, respectively, 3.7 x 10^9 and 1 x 10^0 CFU GDW^-1, whereas on new root the number of bacteria was 2.5 x 10^10 CFU GDW^-1. Among the physiological groups of heterotrophie bacteria analyzed, amylolytic bacteria were the most numerous. Their maximum counts on the surface of submerged fragments of plants, in soil and on old (from the previous year) roots reached between less than ten million, less than a hundred million and more units. Lipolytic and protcolytic bacteria were present in smaller numbers; they only sporadically reached between less than ten million or less than a hundred million CFU GDW ^-1. The differences in the counts of the physiological groups of hctcrotrophic bacteria in water and on different plant fragments between the two studied sites were small and never exceeded one order of value. The results suggest that microbiological mineralization of organic contents in wetland occurs mostly at the borderline of water and plant phases.

Badano liczebność bakterii heterotroficznych i niektórych grup fizjologicznych tych drobnoustrojów (amylolitycznyeh, lipolityeznyeh, proteolitycznych, kazeolityeznyeh) w wodzie, glebie i turzycy błotnej (Carex acutiformis Ehrb.) jednego z większych obszarów bagiennych w rejonie leśniczówki Stary Dwór koło Olsztyna. Ogólna liczba bakterii heterotroficznych w wodzie badanego wetlandu nie przekraczała 2,3 x 105 jtk cm3; na roślinach 3,4 x 10'jtk g_sm' w części zanurzonej w wodzie i 1,6 x 10'jtk g_sm w części napowietrznej. W glebie i na powierzchni korzeni starszych odpowiednio 3,7 x 10' i 1 x 10'jtk g_sm, na korzeniach nowych 2,5 x 10'° jtk g_sm- Spośród badanych grup fizjologicznych bakterii heterotroficznych najliczniej reprezentowane były bakterie amylolityczne i kazeolityczne. Maksymalne ich liczebności na powierzchni zanurzonych w wodzie fragmentów roślin, w glebie i na korzeniach starych (ubiegłorocznych) osiągała czasami kilka, kilkadziesiąt i więcej milionów jtk g_sm. Bakterie lipolityczne i proteolityczne występowały w mniejszych ilościach; tylko sporadycznie osiągały wartości rzędu kilku, kilkudziesięciu milionów jtk g_sm. Wyniki badań sugerują, iż główna część procesów mikrobiologicznych przemian związków organicznych w wetlandzie odbywa się na styku woda - roślina - gleba.