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Changes in carbon storage of Masson Pine Forests along a latitudinal gradient with different stand structures in Southern China

Wu Qiang, Ma Hengyun, Peng Yuanying, Yan Wende, Pan Deng

Polish Journal of Ecology

2021

Vol. 69, nr 3-4

137--155

The spatial patterns of carbon pool in landscape vary greatly with variation of forest structures and climate conditions. In this field study, the carbon storage in overstory, understory, litter layer of plants and soil carbon in forests was investigated in 26-28 year-old Masson pine (Pinus massoniana) pure and mixed forests along a latitudinal gradient (20–30 °N) crossing Hunan and Guangxi provinces of China, during the period of May 2015–August 2017. We found that the total carbon storage in Masson pine forests ranged 88.92–149.41 Mg/ha, of which 54.03% occurred in aboveground compound and 45.97% occurred belowground. The overall total carbon storage distribution was 34.62–68.72 Mg/ha, 3.82–10.19 Mg/ha, 2.37–3.96 Mg/ha, and 6.06–12.08 Mg/ha in stems, branches, leaves, and roots, respectively. The carbon storage in the overstory of forest stands and forest soils significantly decreased with increasing latitude, while the carbon storage in the understory and litter of the forest stands significantly increased as the latitude increased. The overall carbon storage significantly decreases by 8.26 Mg/ha in Masson pine forests as the latitude increased by one degree. The carbon storage increased by 8.43% in Masson pine mixed forests compared to the pure forest stands after the transformation from the pure forest stands into the mixed forest stands ∼ 15 years later. The results of changes in carbon storage in the studied forests with the latitudinal gradient could be attributed to variations in hydrothermal conditions with changing latitudes. The forest structure with different tree species composition was another important factor regulating carbon storage in forest ecosystems at the same latitude. The results provided a scientific basis for better understanding of latitudinal variation and spatial distribution of carbon storage in Masson pine forest stands with optimal forest stand structures in subtropical region of China.

Dry matter and protein yields and leaf greenness index (SPAD) of alfalfa and festulolium depending on cultivation method and soil moisture level

Staniak M.

Journal of Research and Applications in Agricultural Engineering

2018

Vol. 63, nr 3

92--97

The aim of the study was to assess the influence of water deficiency in the soil and cultivation method on dry matter and protein yields as well relative chlorophyll content of alfalfa and festulolium leaves. The pot experiment was conducted in the years 2012-2014 in the greenhouse of IUNG-PIB in Puławy, in a completely randomized system, in 4 repetitions. The research included alfalfa and festulolium cultivated in pure stand and in a mixture, at two soil moisture levels: 70% field water capacity (optimal humidity) and 40% FWC (drought stress). The study showed that long-term drought stress significantly reduced the dry matter yield of alfalfa and festulolium, with the highest loss in pure alfalfa stand (by 39.8% on average), lower in the mixture (by 29.1%), and lowest in pure festulolium stand (by 13.6%). Regardless of the soil moisture conditions, the highest total protein yield was obtained from alfalfa grown in pure stand, and lower by only 12% from the mixture. The protein yield from festulolium cultivated in pure stand was, on average, lower by 68% in comparison with the yield of alfalfa. The greenness index of the alfalfa leaf was significantly higher than that of the hybrid festulolium, regardless of the soil moisture conditions. The water requirement in the soil and the method of cultivation did not significantly differentiate the relative content of chlorophyll in the leaves of the tested plant species.

Celem badań była ocena wpływu niedoboru wody w glebie oraz sposobu uprawy na plon suchej masy i białka oraz względną zawartość chlorofilu w liściach lucerny i festulolium. Doświadczenie wazonowe przeprowadzono w latach 2012-2014 w hali wegetacyjnej IUNG-PIB w Puławach, w układzie kompletnie zrandomizowanym, w 4 powtórzeniach. W badaniach uwzględniono lucernę siewną i festulolium uprawiane w siewach czystych i w mieszance, przy 2 poziomach wilgotności gleby: 70% polowej pojemności wodnej (wilgotność optymalna) i 40% ppw (stres suszy). W badaniach wykazano, że długotrwały stres suszy istotnie redukował plon suchej masy lucerny i festulolium, przy czym największą stratę wykazano w czystym zasiewie lucerny (średnio o 39.8%), mniejszą u mieszanki (o 29.1%), a w najmniejszą u mieszańca festulolium (o 13.6%). Niezależnie od warunków wilgotnościowych gleby, największy łączny plon białka ogólnego uzyskano z uprawy lucerny w siewie czystym, a tylko o 12% mniejszy z uprawy mieszanki. Plon białka z uprawy festulolium w siewie czystym był średnio o 68% mniejszy w porównaniu do plonu lucerny. Indeks zieloności liścia (SPAD) lucerny był istotnie większy w porównaniu do mieszańca festulolium, niezależnie od warunków wilgotnościowych gleby. Niedobór wody w glebie i sposób uprawy nie różnicowały istotnie względnej zawartości chlorofilu w liściach badanych gatunków roślin.