Processes Of Vegetation Change Research Articles

Multi-source remote sensing data shows a significant increase in vegetation on the Tibetan Plateau since 2000

In recent years, there has been growing concern that vegetation changes on the Tibetan Plateau are associated with climate change (temperature and precipitation) and human activities. This study used six types of remote sensing vegetation data, including GIMMS (Global Inventory Modelling and Mapping Studies) NDVI (Normalized Difference Vegetation Index), MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI, MODIS EVI (Enhanced Vegetation Index), SPOT Vegetation (Spot-VGT) NDVI, LAI (Leaf Area Index) and NPP (Net Primary Productivity), and applied the maximum synthesis method, trend analysis, correlation analysis, and multivariate statistical analysis to investigate vegetation change processes since the 1980s. The study showed that the amount of vegetation on the TP had increased significantly since 2000 ( p < .01), especially in the northeastern part of the TP. There was no significant change prior to 2000. The different vegetation data sources varied greatly. Four remote sensing indices, MODIS EVI, Spot-VGT NDVI, LAI, and NPP, showed a significant increase in vegetation from 2000, accounting for 16.18%, 44.55%, 30.44% and 8.94% of the total area, respectively ( p < .05). Multiple data sources provided a more comprehensive understanding, whereas a single data source had substantial uncertainty. Human activities, such as the implementation of large-scale ecological projects, played a dominant role in increasing vegetation, while climate change played a subsidiary role. The MODIS EVI, Spot-VGT NDVI, LAI, and NPP data showed that the area of increased vegetation caused by human activities accounted for 53.51%, 45.68%, 37.52%, and 31.79% of the total area of the TP, respectively. The relative increase from climate change was 10.28%, 17.49%, 13.15%, and 8.82%, respectively. The current study applied multi-source remotely sensed vegetation data, which effectively reduced the uncertainty caused by individual data sources and provided more rigorous and scientific research conclusions.

Spatial patterns of vegetation coverage change in giant panda habitat based on MODIS time-series observations and local indicators of spatial association

Measures to characterize the spatial patterns of vegetation change can provide important information for understanding and assessing habitat fragmentation and its causes. This study developed a new framework to assess fragmentation by integrating the spatial patterns of vegetation coverage and its change across the giant panda habitat ecosystem of China. Based on Moderate Resolution Imaging Spectroradiometer (MODIS) time-series data, we detected the historical vegetation disturbances and used “abrupt,” “gradual,” and “total” to characterize the vegetation change processes from 2000 to 2017. The spatial patterns of vegetation coverage and its change were described by spatial clusters and outliers, and the framework was established to find the potential area for reduction of habitat fragmentation. The results indicated that 1.9% of the study area experienced disturbances during 2000–2017. Most of the disturbed area (78.9%) experienced negative abrupt vegetation change, and the undisturbed area mainly showed an increase in vegetation (85.8%). The spatial clusters of high and low total changes accounted for 22.7% and 18.2% of the study area, respectively. The high change clusters were primarily along the northern and southeastern borders of the giant panda habitat, while the low change clusters spread over the central and southern areas. Considering the spatial patterns of both vegetation coverage and its change, 12.7% of the study area, located mainly in southern Minshan and eastern Qionglaishan, needs careful management to reduce habitat fragmentation. This study provides new insight to understand habitat fragmentation in terms of spatial and temporal characteristics of vegetation status and change, and will benefit future habitat management efforts.

Detecting Spatiotemporal Changes in Vegetation with the BFAST Model in the Qilian Mountain Region during 2000–2017

The Qilian Mountain ecosystems play an irreplaceable role in maintaining ecological security in western China. Vegetation, as an important part of the ecosystem, has undergone considerable changes in recent decades in this area, but few studies have focused on the process of vegetation change. A long normalized difference vegetation index (NDVI) time series dataset based on remote sensing is an effective tool to investigate large-scale vegetation change dynamics. The MODerate resolution Imaging Spectroradiometer (MODIS) NDVI dataset has provided very detailed regional to global information on the state of vegetation since 2000. The aim of this study was to explore the spatial-temporal characteristics of abrupt vegetation changes and detect their potential drivers in the Qilian Mountain area using MODIS NDVI data with 1 km resolution from 2000 to 2017. The Breaks for Additive Season and Trend (BFAST) algorithm was adopted to detect vegetation breakpoint change times and magnitudes from satellite observations. Our results indicated that approximately 80.1% of vegetation areas experienced at least one abrupt change from 2000 to 2017, and most of these areas were distributed in the southern and northern parts of the study area, especially the area surrounding Qinghai Lake. The abrupt browning changes were much more widespread than the abrupt greening changes for most years of the study period. Environmental factors and anthropogenic activities mainly drove the abrupt vegetation changes. Long-term overgrazing is likely the main cause of the abrupt browning changes. In addition, our results indicate that national ecological protection policies have achieved positive effects in the study area.

Estimating aboveground woody biomass change in Kalahari woodland: combining field, radar, and optical data sets

ABSTRACTMaps that accurately quantify aboveground vegetation biomass (AGB) are essential for ecosystem monitoring and conservation. Throughout Namibia, four vegetation change processes are widespread, namely, deforestation, woodland degradation, the encroachment of the herbaceous and grassy layers by woody strata (woody thickening), and woodland regrowth. All of these vegetation change processes affect a range of key ecosystem services, yet their spatial and temporal dynamics and contributions to AGB change remain poorly understood. This study quantifies AGB associated with the different vegetation change processes over an 8-year period, for a region of Kalahari woodland savannah in northern Namibia. Using data from 101 forest inventory plots collected during two field campaigns (2014–2015), we model AGB as a function of the Advanced Land Observing Satellite Phased Array L-band synthetic aperture radar (PALSAR and PALSAR-2) and dry season Landsat vegetation index composites, for two periods (2007 and 2015). Differences in AGB between 2007 and 2015 were assessed and validated using independent data, and changes in AGB for the main vegetation processes are quantified for the whole study area (75,501 km2). We find that woodland degradation and woody thickening contributed a change in AGB of −14.3 and 2.5 Tg over 14% and 3.5% of the study area, respectively. Deforestation and regrowth contributed a smaller portion of AGB change, i.e. −1.9 and 0.2 Tg over 1.3% and 0.2% of the study area, respectively.

The Medicine Tree: Unsettling palaeoecological perceptions of past environments and human activity

In this paper, we consider palaeoecological approaches to past landscapes and reflect upon how these are relevant to archaeological themes concerning concepts of environmental change and the role of past and present human communities in these processes. In particular, we highlight the importance of local context in the perception and understanding of landscape. Utilising a case study from Nepal, we look to ‘unsettle’ a conventional palaeoecological interpretation of a pollen record, originally constructed on western ecological principles, and instead draw on an interpretative perspective rooted in local Buddhist ecological knowledge, or a ‘folk taxonomy’, known as ‘The Medicine Tree’. We discuss how the interpretations of patterns and processes of vegetation change from a pollen record are not necessarily absolute. In particular, we outline how the palaeoecological frame of enquiry and reference is rooted in an essentially Eurocentric, Western scientific paradigm, which, in turn, shapes how we perceive and conceive of past landscapes and the role of ‘anthropogenic impact’ on vegetation. The aim of this is not to suggest that scientific approaches to the ‘reconstruction’ of past landscapes are necessarily invalid, but to illustrate how ‘empirical’ scientific methods and interpretations in archaeological science are contingent upon specific social and cultural frames of reference. We discuss the broader relevance of this, such as how we interpret past human activity and perception of landscape change, the ways in which we might look to mobilise research in the context of contemporary problems, issues concerning ‘degraded landscapes’ and how we incorporate local and archaeological perspectives with palaeoecology within an interconnected and iterative process.

Unraveling the naturalness of sweet chestnut forests (Castanea sativa Mill.) in central Spain

This paper describes the patterns and processes of vegetation change and fire history in the Late Holocene (c. 3,140 cal bp) palaeoecological sequence of El Tiemblo, in a mountainous area in central Spain (Gredos range, Spanish Central System), and provides the first Iberian pollen sequence undertaken within a Castanea sativa-dominated woodland. These new data reassess not only the autochthonous nature of the species in the region and in the Iberian Peninsula, but also the naturalness of well-developed sweet chestnut forests. The study focuses on anthropogenic dynamics linked both to the effects of livestock husbandry and the use of fire for forest clearance. With this aim, non-pollen palynomorphs (coprophilous fungi ascospores) and charcoal accumulation rate are useful indicators for assessing the increasing role of human influence on vegetation.

Pattern and process of vegetation change (succession) on two northern New Zealand island volcanoes

Pattern and process of vegetation change (succession) were compared on two northern North Island volcanoes: Whakaari (White Island) and Rangitoto Island where the endemic woody tree Metrosideros excelsa is the primary colonizer of raw volcanic substrates. Quantitative data from our previous publications (see References) and the references therein illustrate sequences of vegetation succession following significant volcanic eruptions. New information on Rangitoto Island M. excelsa patch dynamics and updated vascular species statistics for Whakaari have also been included. We also draw on supporting data from M. excelsa forest on the mainland and long-inactive volcanic islands in the Bay of Plenty, to provide a context for understanding the vegetation dynamics on Whakaari and Rangitoto Island. Species facilitation, light availability, humidity, substrate and disturbance history are all key determinants of vegetation succession across these volcanic landscapes.

Fire management in a changing landscape: a case study from Lopé National Park, Gabon

A key management goal in Lope National Park, Gabon, is to protect regionally-rare savannah ecosystems within the continuous rainforest block. In order to evaluate the impact of existing protection efforts, data on burning season environmental conditions, burning effort and current woody values for savannahs were examined between 1995 and 2008. Results showed (a) spatial heterogeneity in woody values to be correlated with grassy vegetation type (b) a negative relationship between woody vegetation and fire return frequency over the study, suggesting that decreased fire return frequency may favour savannah thickening and (c) that inconsistent burn effort by Park staff, and burns designed for reduced heat, may limit the efficiency of fire to prevent savannah thickening or forest expansion. Optimal humidity and fuel moisture conditions for burning are identified and recommendations made for improving the existing fire plan to achieve the management goal. Modifications will require significant investment of resources and training and require urgent experimental work to disentangle the direct impacts of fire from other processes of vegetation change. Lope’s fire policy should ultimately be a dynamic response to change in the local landscape driven by direct fire impacts or by global climate change.

黄土高原沟壑区森林带不同植物群落土壤氮素含量及其转化

PDF HTML阅读 XML下载 导出引用 引用提醒 黄土高原沟壑区森林带不同植物群落土壤氮素含量及其转化 DOI: 10.5846/stxb201207211037 作者: 作者单位: 西北农林科技大学 资源环境学院,西北农林科技大学 资源环境学院,西北农林科技大学 黄土高原土壤侵蚀与旱地农业国家重点实验室,西北农林科技大学 资源环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目（41030532，41101254）；西北农林科技大学基本科研费资助项目（QN2011020） Soil nitrogen concentrations and transformations under different vegetation types in forested zones of the Loess Gully Region Author: Affiliation: College of Resource and Environmental Science,Northwest A F University,Yanglin,Shanxi,College of Resource and Environmental Science,Northwest A F University,Yanglin,Shanxi,State Key Laboratory of Ssoil Erosion and Dryland Agriculture of Loess Plateau Yanglin,Shanxi,College of Resource and Environmental Science,Northwest A F University,Yanglin,Shanxi Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了探讨在黄土高原退耕还林还草过程中植物群落对土壤氮素含量及形态分布的影响，选择退耕历史较长的黄土高原沟壑区——安塞县洞子沟流域8种典型植物群落下0-10cm和10-20cm的土壤为对象，测定了土壤中有机氮、矿化氮、微生物量氮和硝态氮和铵态氮的含量。结果表明，从草本群落到乔灌草群落，土壤各形态氮素含量均增加，整体表现为乔灌草群落 > 灌草群落 > 草本群落。然而人工刺槐林的土壤氮素水平远低于自然恢复的乔灌草群落，甚至低于灌草群落。0-10cm 土层各形态氮素均低于10-20cm 土层。硝态氮对植物群落的变化最为敏感，可作为土壤氮素水平的敏感指标。土壤有机质、pH、容重与氮素含量极显著相关，各种氮素间极显著正相关。各种氮素占总氮的比例对总氮的变化有着不同的响应，有机氮、可矿化氮和微生物量氮占总氮的比例相对稳定，硝态氮占总氮的比例随总氮含量的增加而增加，铵态氮占总氮的比例随总氮含量的增加而降低。 Abstract:The "Grain for Green" project is essential for controlling soil erosion in the Gully Region of the Loess Plateau, which has one of the most serious water and soil loss problems in the world. Different vegetation types change the soil environment to different extents, influencing the biogeochemical cycles of materials, such as nitrogen (N). At present, a growing number of researchers are investigating the relationship between vegetation and N forms in natural ecological systems to provide a theoretical basis for ecological restoration in these areas. In this paper, the effect of vegetation types on the concentration and transformation of various soil N types (soil total N, organic N, N mineralizable within 14 d, microbial biomass N, nitrate N and ammonium N) in the Dongzigou Basin, Ansai, Shaanxi Province was investigated. Soil samples were collected from the 0-10 and 10-20 cm layers under eight typical vegetation types, including Quercus liaotungensis, Acer buergerianum Miq, Platycladus orientalis, Robinia pseudoacacia, Syzygium aromaticum, Sophora davidii, Artemisia giraldii Pamp. and Artemisia sacrorum Ledeb. The results showed that the six types of soil N as a whole gradually increased as vegetative succession proceeded from grass communities to more complex mixtures of trees, bushes and grasses. Overall, the maximal N concentration occurred under Q. liaotungensis, while the minimum occurred under A. sacrorum Ledeb. Soil total N ranged from 0.35 to 3.22g/kg at 0-10 cm, the maximum value being 9.2 times the minimal. For organic N, N mineralizable within 14 d, microbial biomass N, nitrate N and ammonium N, the maximum value was 9.3, 8.7, 6.4, 9.0 and 2.3 times the minimum, respectively. Soil N concentrations under artificial R. pseudoacacia forests were lower than those under natural successional vegetation. The various soil N concentrations all were higher at 0-10 cm than 10-20 cm. Nitrate N changed more quickly than the other N fractions; therefore, nitrate N could be used as a sensitive indicator of early changes in soil N during natural succession. Soil organic matter, pH, and bulk density were closely related to soil N. There was a significant positive correlation among the six N fractions; however, the ratio of each N fraction to total N responded differently to changes in total N. Specifically, the ratio of organic N, N mineralizable within 14 days, and microbial biomass N to total N did not change, regardless of the total soil N concentration. In contrast, the ratio of nitrate N to total soil N increased as the total soil N concentration increased, whereas the ratio of ammonium N to total N decreased. The ratio of nitrate N to total N was positively correlated with total N (r=0.58), while the ratio of ammonium N to total N was significantly negatively correlated with total N (r=-0.83). Further research is still required to explore the processes of vegetation change and N transformation. 参考文献 相似文献 引证文献

Vegetation Change from the Euro-American Settlement Era to the Present in Relation to Environment and Disturbance in Southwest Oregon

Faced with landscapes degraded by fire suppression, logging, and grazing, land managers in the interior western US are attempting to restore habitat structure and function. In southwest Oregon, landscape-scale fuels treatments are being implemented with goals including recreating historic vegetation structure, despite poor understanding of the nature of the landscape prior to widespread Euro-American influence, or the patterns and processes of vegetation change over time. We compared a General Land Office-based reconstruction of Euro-American settlement era (1850s) vegetation in southwest Oregon's interior valleys and foothills with modern vegetation interpreted from aerial orthoimages to determine patterns of vegetation distribution in both eras, trajectories of vegetation change, and environmental and disturbance factors related to these themes. We found that this landscape was primarily occupied by closed plant community types in both eras, with a comparatively minor proportion in open types; vegetation was distributed along a dominant environmental gradient that ran from prairies in xeric lowlands to conifer forests in steeper, cooler uplands. Temporal shifts from open to closed vegetation were consistent with expected effects of fire suppression in many cases, but in other cases, the long-term persistence of open vegetation in the absence of recorded fire indicated that other mechanisms were also in operation. Human encroachment into wildlands, particularly in valleys, has also been a major driver of landscape-level change in the past 150 yr. Our results suggest that conservation should focus on lowlands, particularly where uncommon vegetation types such as savanna, shrubland, and prairie still exist.

Changes in plant species and functional composition with time since fire in two mediterranean climate plant communities

AbstractQuestionDo floristic composition and plant functional type (PFT) richness and dominance change with time since fire, in the directions predicted through consideration of their fire response traits?LocationTwo vegetation communities in the globally significant biodiversity hotspot of south‐western Australia: mallee, dominated by resprouters, and mallee‐heath, dominated by non‐resprouters.MethodsSpecies richness and cover were sampled in replicated plots across a time since fire gradient ranging from 2 to >55 yr post‐fire, using a space‐for‐time approach. Species were allocated to PFTs according to traits relevant to the processes of vegetation change underpinning the initial floristic composition model of vegetation assembly: their capacity to resprout, the location and persistence of the seed bank, competitive stratum and longevity. Ordination and ANOVA were used to test for differences in floristic and PFT composition between young (<10 yr post‐fire), mature (18–35 yr) and old (>40 yr) vegetation in each community.ResultsPlant functional type and floristic analyses were similar, showing substantial changes in the composition of mallee‐heath vegetation with time since fire, but not in mallee. The direction of change in PFT composition in mallee‐heath was consistent with predictions, with increasing cover of non‐resprouting, serotinous PFTs, an intermediate peak in cover of PFTs with persistent soil‐stored seed banks, and decreasing cover of post‐fire ephemerals and non‐resprouting, non‐serotinous dwarf shrubs, herbs and graminoids with increasing time since fire. Success in predicting changes in PFT dominance in mallee was lower.ConclusionsThe similarity of floristic and PFT analyses suggest that these approaches are interchangeable for characterizing vegetation change with increasing time since fire. PFTs were more effective for predicting fire response trajectories in the vegetation community dominated by non‐resprouting, serotinous shrubs (mallee‐heath) than that dominated by resprouting, serotinous trees (mallee). The underlying vegetation assembly model and PFTs used appear suitable for broader application in fire‐prone communities with competitive dominance by non‐resprouting, serotinous shrubs, but less so in communities dominated by other PFTs.

黄土丘陵区子午岭不同植物群落下土壤氮素及相关酶活性的特征

以黄土丘陵区子午岭林区裸露地为对照,选择撂荒地、白羊草草地、油松、山杨和辽东栎林地五种典型植被群落下0-10 cm和10-20 cm土层的土壤为研究对象,对土壤无机氮、有机氮、微生物量氮含量和脲酶、蛋白酶以及硝酸还原酶的活性进行了研究。结果表明,土壤中各种氮素基本表现为乔木林,尤其是辽东栎和油松下含量最高,而有机氮则在白羊草地富集明显。铵态氮为子午岭林区速效氮的主要形式。土壤铵态氮与微生物氮极显著正相关;有机氮和亚硝态氮、矿化氮、微生物氮均显著正相关。脲酶和硝酸还原酶活性在辽东栎群落下最高,蛋白酶在白羊草地下较高,且脲酶活性在土壤上层高于下层,而蛋白酶和硝酸还原酶并没有表现出明显规律。脲酶活性和铵态氮、有机氮含量显著正相关,与微生物量氮极显著正相关;硝酸还原酶活性与铵态氮含量显著正相关;蛋白酶活性和土壤各种氮素含量无相关性。

Late Holocene ecological history of Pinus pinaster forests in the Sierra de Gredos of central Spain

This article describes the patterns and processes of vegetation change and fire history in the Late Holocene (c. 2400 calendar year BP) palaeoecological sequence of Lanzahita, Sierra de Gredos in central Spain, and provides the first Iberian pollen sequence undertaken within a monospecific Pinus pinaster woodland. These new data reassess not only the autochthonous nature of this pine species in the region and the Iberian Peninsula, but also the naturalness of well-developed cluster pine forests. Conflicts of palaeoecological evidence with phytosociological models of vegetation dynamics in the study region, and the relationships of P. pinaster with fire occurrence in Mediterranean-type ecosystems, are discussed.

The Archaeological Significance of Patterns of Anomalous Vegetation on a Raised Mire in the Solway Estuary and the Processes Involved in their Formation

While the location and identification of archaeological features from vegetative responses on “dry-sites” is well understood in a British context, its application to wet sites is less well explored. Following the recovery of Glasson Moss, Cumbria, from a major fire in 1976, and a programme of hydrological restoration, a pattern of circular and linear features was observed during a field survey in the mid-1990s. Assessment of the archaeological significance of these features was undertaken in 1996 and 1997 using aerial photography, fieldwork and historical research. The results suggest that during the Early Mediaeval period, natural pools within the moss were used for hemp retting. It appears that water levels within the pools were controlled by the construction of narrow ditches with possible simple sluice systems. One pool was examined in detail; it was used for retting from c.7th century ad until it dried out during the late 12th to mid-13th centuries. Disruption to the mire hydrology, possibly combined with trampling activity around the pool and ditch, appears to have instigated vegetation succession, which resulted ultimately in the colonization of the edges of both pool and ditch by swathes ofCalluna vulgaris (heather). The time scale involved in these changes is unknown, although similar responses were noted as beginning to occur at the site of nearby tithe apportionment boundaries (narrow ditches) dating from 1816. This process of vegetation change is examined.

Floristic, biogeographical, and vegetational aspects of Pre-Cambrian rock outcrops (inselbergs) in eastern Bolivia

Pre-Cambrian rock outcrops (inselbergs) are insular and azonal habitats within forest formations. In the context of a global inselberg research project first insights into the flora and vegetation of inselbergs (,lajas‘) of eastern Bolivia are given. The few mentions in literature and own field observations in the provinces of Ñuflo de Chavez and Velasco (Dept. Santa Cruz) are considered. The typical flora is characterized. Some inselberg endemics are known but the majority of the species shows a wide distribution and occurrence in other habitats. E.g. the Guianan Vellozia tubiflora and the Chacoan Cereus (Monvillea) kroenleinii have been found in Bolivia for the first time. A preliminary physiognomic characterization of the most important formations of the vegetation (e.g. exposed rock surfaces, rock pools, plant-mats) is realized. The floristic and vegetational observations fit well into the patterns known from other tropical inselbergs. Ideas are proposed, which refer to natural processes of vegetation change – the floristic diversity on the Pre-Cambrian rock outcrops is maintained by succession and degradation.

BOOK REVIEWS

Journal of Vegetation ScienceVolume 3, Issue 5 p. 719-719 Free Access BOOK REVIEWS First published: October 1992 https://doi.org/10.2307/3235842AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Burrows, C. J. 1990. Processes of Vegetation Change. Volume3, Issue5October 1992Pages 719-719 RelatedInformation

Soil heavy metal concentrations and erosion damage in upland grasslands in the Pennines, England

The relationship between grassland stability and soil concentrations of Pb, Zn and Cd and soil pH were determined at two abandoned heavy metal mine complexes in the Yorkshire Pennines, England. A process of vegetation change, in which degenerative stages are currently predominant occurs on the finer textured spoils, which are physically and chemically extremely heterogeneous. Physical disruption of closed grassland and floristic changes are involved in this process. There was little evidence that soil heavy metal concentrations, with the possible exception of Zn, were involved in initiating the process. Soil pH was unrelated to metal concentrations or to the disruption. Causes of initiation are not yet known, but these results indicate that more than one factor is involved. There was evidence that later stages of the disruptive process are powered by frost-heave and water erosion.

Holocene book reviews : Processes of vegetation change

Holocene book reviews : Processes of vegetation change

NATURAL AND ANTHROPOGENIC MECHANISMS OF IMPACT ON PASTURES PLANT COMMUNITIES IN THE NORTH-WESTERN CASPIAN REGION

The data from field studies on the influence of anthropogenic and ecological mechanisms on the species of forage plants of natural pasture phytocenoses is presented in the article. An explanation for the development of vegetation change processes in phytocenoses under existing conditions is given. The influence on the change in the structure of vegetation, the processes of transformation of communities has been studied. A noticeable decrease in the productivity of phytocenoses was shown at an unstandardized load of 3-4 sheep per hectare.Studies have established the negative influence of external mechanisms on the preservation of valuable forage grasses, depending on the different modes of use of pastures in the North-Western Caspian region. A noticeable decrease in the dynamics of productivity of phytocenoses with an increased load in the range of 4.54-2.27 centners / ha in the spring is shown. The results of the conducted studies show that the peculiarities of changes in the vegetation cover are mainly determined by the formation of an anthropogenic landscape with the domination of the most resistant xerophyte dwarf shrubs and the replacement of indigenous species of the community with unsuitable plant species for food that are formed in a continental climate. Changes in the composition of the vegetation cover, the ratio of species of forage grasses with different adaptive strategies were studied. Found significant changes in the vegetation cover in the experimental plots with non-standardized load. The grass stand is sparse, with a low projective cover of 32-67%. In places of failure, one- and two-year-old plants grow with some poorly eaten perennials; loss of unstable species, especially cereals, is observed. Areas of phytocenoses with a moderate load were characterized by an average of 72% projective cover due to the content of the proportion of grasses, forbs and xerophytes with a high level of adaptation and resistance to various mechanisms of influence.