Influence Of Plantations Research Articles

Understory vegetation diversity and composition in intensively managed plantations compared to extensively managed forests

The benefits of plantations for wood production are well known, but it is unclear whether they have a clear negative effect on biodiversity, compared to natural forests. It is also unclear how overstory species identity (i.e., exotic, compared to native) would interact with the simple plantation effects on understory vegetation biodiversity. Here, we assessed bryophyte, lichen, and vascular plant diversity and composition in mono-specific and mixed plantations of exotic and native hybrid poplars (Populus spp.) and exotic and native spruces (Picea spp.). We compared these plantations to reference forests with similar overstory types (coniferous, deciduous, mixed) to those of the plantations in the southern boreal forest of Quebec. We also assessed whether the overstory species identity in plantations influenced understory vegetation biodiversity compared to reference forests. Our results show that plantations were not biological deserts, since mixed plantations contained similar bryophyte and vascular plant diversity as reference mixed native forests. The presence of native spruces and exotic poplars in mixed plantations increased bryophyte and vascular plant diversity respectively. This suggests that the influence of plantations on understory species diversity, compared to reference forests, was linked to the overstory species identity. Plantations were associated with ruderal plant species, while reference forests were composed of forest species. Bryophyte composition was similar in plantations and reference forests, while lichen species were only present in plantations. Our findings highlight that plantations, especially mixtures of white spruce and exotic poplar, are a promising option for planting strategies to enhance biodiversity.

Influence of Plantation in a Saline-Stressed Location on the Agronomical Characteristics and Technological Quality of Flour and Baladi Bread for Two Egyptian Wheat Varieties

Influence of Plantation in a Saline-Stressed Location on the Agronomical Characteristics and Technological Quality of Flour and Baladi Bread for Two Egyptian Wheat Varieties

The Influence of Plantation on Soil Carbon and Nutrients: Focusing on Tibetan Artificial Forests

As terrestrial ecosystem carbon (C) sinks, plantation ecosystems play essential roles in species diversity protection, resource supply and climate change. Artificial afforestation is of great important in improving the ecological condition, economic development and production in Tibet. Forests can improve soil property changes, yet the understanding of how plantations influence soil C and nutrient conditions in Tibet is still insufficient. This review combines with previous studies to explore the characteristics of soil nutrients, involving nitrogen (N) and phosphorus (P) on Tibetan poplar plantations. Generally, plantations have better abilities in improving the soil C and N cycles, and enhancing the soil stability. In this review, we further analyze the factors, including the modality of land-use, afforested period, tree species, climate factors and soil properties, which may affect the soil C and nutrients. (1) The patterns of land-use affect the accumulation of soil organic matter, thus influence the accumulation of soil C and nutrients; (2) Soil C and N increase with the years of artificial forests, while soil P is on the contrary; (3) The effects of different tree species on soil C and nutrients vary widely; (4) In terms of climate, the C sink of Tibetan plantation soil is most likely to be affected by precipitation, while the nutrient is more likely to be influenced by temperature; (5) Among soil properties, the most related factor to C is soil texture. Furthermore, our review pointed out that future research on soil ecological functions should be focused on soil microbes on Tibet plantation. At the end, we concluded three major challenges for the future research. Therefore, this review contributes to a better understand the effects of plantation on soil C and nutrients on the Tibetan Plateau.

Почвенные характеристики эмбриоземов под покровом сосновых насаждений на техногенных элювиях Кузбасса

The article studies the edificatory role of pine growing on the technogenic landscapes of the Kuznetsk coal basin and considers the influence of plantations of Scots pine (Pinus sylvestris L.) with different crown density on the main characteristics of embryozems on the overburden dumps of the coal mining industry. The object of the study was soil samples collected in various zones of the phytogenic fields of pine growing on the transport-free dump of the Kedrovsky coal mine. When choosing test plots, the plantations were ranked according to crown density into unclosed (crown density about 30 %), medium-closed (about 60 %) and closed (about 90 %). In each gradation of closeness, the following zones of influence (phytogenic fields) of trees were identified: undercrown, near-crown (intermediate). The selection of sampling points was carried out taking into account the presence of the identification signs: solid pine litter (undercrown zone), developed moss cover (near-crown zone) and developed meadow vegetation (outer zone). External zones are not found in unclosed and medium-closed plantations. In total, according to the degree of crown density and zoning of phytogenic fields, 7 plantation sites of Pinus sylvestris were identified. Soil samples were taken at each of them from a depth of 0–20 cm in the 3rd decade of September. The enzyme activity was studied in recently collected soil in in 3-fold replications. The fractional composition of soils and their agrochemical properties were determined in dried soil on the basis of the Center for Agrochemical Service “Kemerovo”. The analysis of the results showed that pine stands contribute to accelerated disintegration of technogenic residual rocks with the formation of fine-grained fractions, which are of great soil and environmental importance. Litter combined with grassy vegetation in open pine stands favors the accumulation of total nitrogen in embryozems. It was revealed that the content of readily available forms of phosphorus and potassium depends on lithogenic rather than phytocenotic factors. The study of the enzymatic activity of soils showed that the phosphatase activity decreases with an increase in the phosphorus content, and the protease activity increases with an increase in the nitrogen content. Agrochemical indicators of embryozems are favorable for the growth of herbaceous plants due to horizontal differentiation of space under the influence of stands of Scots pine.

Influence of plantation of a shelter-belt on component of organic carbon in the Taklimakan desert over last decade

The soils were collected from the Taklimakan Desert Highway shelter-belt with different planting years in Xinjiang, northwest of China. The soil organic carbon stork (SOCstork) in each layers. By chemical and physical pretreatment, we measured four carbon passive organic carbons, i.e., microaggregates organic carbon(OCMIA), humus organic carbon (OCHS), carbon resistance to oxidation (OCNaClO) and acid hydrolysis (OCHCl). The results showed that the OC and SOCstorkwas decreased with soil depth mainly in 0-50 cm. The artificial vegetation have more influence on TOC, OCMIAand OCHSthan OCNaClOand OCHCl. The Tamarix chinensis shelter-belt is the most helpful for carbon sequestration in sandy soil and stabilization in surface layer than Calligonum mongolicunl and Haloxylon ammodendron.

Influence of Eucalyptus globulus plantation growth on water table levels and low flows in a small catchment

Summary In a catchment with a shallow water table, switching land use from fodder maize and pasture to Eucalyptus globulus plantation altered dry season hydrology: the water table fell more rapidly each year, and the concomitant decrease in discharge soon led to the stream drying up every year. During the first 3 years of growth, the rate of fall of the water table, S , remained stable in spite of rapid stand growth, which is attributed to transpiration in the catchment being dominated by the background vegetation during this period. Between the third and sixth years, S increased linearly with foliage biomass W s (calculated with the 3-PG model as a proxy for the transpiration capacity of the stand). Subsequently, the levelling off of W s as the result of canopy cover reaching 100% was reflected by similar behaviour of S . The final values of S , in the range 4.5–4.9 mm day −1 , were just over double the initial values of around 2.2 mm day −1 . The influence of plantation with E. globulus on water reserves and discharge needs to be taken into account by catchment management.

Plantations and biodiversity: A comment on the debate in New Brunswick

The importance of biodiversity has become widely recognized but the best methods for conserving forest biodiversity are still being debated. Central to this debate is the influence of plantations and managed stands on local and landscape-scale biodiversity. A recent paper by Erdle and Pollard in The Forestry Chronicle (2002), which concluded that few plantations are strict monocultures in terms of the total number of tree species, could be interpreted as making the case that plantations have relatively minor consequences for biodiversity. We argue that: (1) it is not only the number of species, but also the identities and relative abundances of species that are of ecological importance, and (2) defining biodiversity in terms of tree species alone is of limited applicability. Existing research in New Brunswick on the impact of plantations on biodiversity at the stand scale reveals potentially significant biodiversity losses, at least in certain taxa. The proposal that incorporating more structural elements (e.g., snags, coarse woody debris, vertical structure) and retaining greater tree species diversity to ameliorate negative consequences of plantations remains a hypothesis to be tested in this region. Scientific information gathered in the following areas will allow better decision making: (1) to what degree are older plantations used by native species? (2) are productivity and survivorship of vertebrates in intensively managed stands similar to those in unmanaged forest? (3) are intensively managed stands suitable habitat for non-vertebrates? (4) are there thresholds in the response of some species to landscape-scale habitat loss caused by intensive forest management? Key words: plantations, biodiversity, species composition, landscape scale, stand structures