草地是全球面积最大的陆地生态系统，它不仅是一种陆地景观，更是发展草地畜牧业的基础。黄土高原毗邻我国农牧交错区，是我国北方重要的生态屏障，过度放牧是造成黄土高原草地植被退化的主要原因之一。因此，揭示草地生产力的空间异质性和时空变化特征，定量评估草地承载能力及草畜压力状态，有利于减轻草地放牧压力，降低草地生态系统的生态风险，促进草地畜牧业的可持续发展。本文利用MODIS遥感数据及统计年鉴数据，分析黄土高原草地生产力的时空演变特征，评价黄土高原草地畜牧业的发展状况，基于草畜平衡理论，评价草－畜之间是否达到平衡状态。为今后黄土高原地区草地畜牧业可持续发展提供科学客观的理论基础和判断依据。本文主要研究结果如下：

（1）2001—2020年黄土高原草地净初级生产力（Net Primary Productivity，NPP）的变化以增加态势为主，2020年草地NPP均值为277.27gC/m²/a，产草量为680.38万吨，二者的空间分布基本保持一致，中部及东部地区单位面积产草量较高，西北地区单位面积产草量较低，空间分布格局稳定。与气温相比，产草量受降水量变化的影响更显著。

（2）1990—2020年黄土高原牲畜存栏量呈先上升后下降再上升的“N”形变化特征，载畜密度在西部、北部、东南部地区较高，中部地区较低。2020年黄土高原牲畜数量为11975.87万羊单位（Sheep Unit，SU），畜牧业总产值为2610.35亿元。黄土高原理论载畜量在空间上表现为由西北向东南逐步增加，理论载畜量较高的地区集中在中部及东部地区，理论载畜量多年平均值为0.67SU/hm²。从年际变化来看，大部分地区的理论载畜量以增加为主，中部及东部地区增加较为明显。

（3）2001—2020年黄土高原地区载畜压力较大，草地呈现超载状态。2020年各省载畜压力由大到小依次为：青海省＞山西省＞内蒙古自治区＞陕西省＞宁夏回族自治区＞甘肃省＞河南省，2020年黄土高原达到超载界限的地区主要集中在北部及西部。通过近20年的生态建设，黄土高原整体草畜平衡状态正在逐步改善，其中陕西省和山西省的改善效果明显。在适度载畜情景下，黄土高原载畜强度约为0.37SU/hm²，黄土高原每公顷可收益约741.49元。

Grassland is the largest terrestrial ecosystem in the world, it is not only a terrestrial landscape, but also the basis for the development of grassland livestock farming. The Loess Plateau is located in the interlocking agricultural and pastoral areas of China, and is an important ecological barrier in the north of China. Overgrazing is one of the main reasons for the degradation of grassland vegetation on the Loess Plateau. Therefore, revealing the spatial heterogeneity and spatial and temporal variation characteristics of grassland productivity, quantitatively assessing the carrying capacity of grassland and the state of grass-livestock pressure, is conducive to reducing the pressure of grassland grazing, reducing the ecological risk of grassland ecosystem, and promoting the sustainable development of grassland animal husbandry. This paper uses MODIS remote sensing data and statistical yearbook data to analyze the spatial and temporal evolution characteristics of grassland productivity on the Loess Plateau, evaluate the development status of grassland livestock husbandry on the Loess Plateau, and evaluate whether the grass-livestock equilibrium is reached based on the theory of grass-livestock equilibrium. It provides a scientific and considerable theoretical basis and judgment for the sustainable development of grassland animal husbandry in the Loess Plateau region in the future. The main research results of this paper are as follows:

(1) Net Primary Productivity (NPP) of grasslands on the Loess Plateau from 2001 to 2020 was mainly increasing, and the average value of NPP of grasslands in 2020 was 277.27 gC/m²/a and the amount of grass produced was 6.838 million tons, and the spatial distribution of both remained basically the same, with higher grass production per unit area in the central and eastern regions and lower grass production per unit area in the northwestern region. The spatial distribution pattern was stable, with higher grass production per unit area in central and eastern regions and lower grass production per unit area in northwestern regions. Compared with temperature, grass production was more significantly influenced by the change of precipitation.

(2) From 1990 to 2020, the livestock stock in Loess Plateau showed an "N" shaped change of rising, then falling and then rising, and the density of livestock was higher in western, northern and southeastern areas and lower in central areas. The total output value of livestock industry is 261.035 billion Yuan. The theoretical livestock carrying capacity of the Loess Plateau is spatially increasing from northwest to southeast, and the higher theoretical livestock carrying capacity is concentrated in the central and eastern regions, with a multi-year average value of 0.67 SU/hm². from the interannual changes, the theoretical livestock carrying capacity of most regions is mainly increasing, and the increase is more obvious in the central and eastern regions.

(3) From 2001 to 2020, the Loess Plateau is under high livestock pressure, and the grassland is overloaded. 2020 livestock pressure in each province is in the following order: Qinghai Province > Shanxi Province > Inner Mongolia Autonomous Region > Shaanxi Province > Ningxia Hui Autonomous Region > Gansu Province > Henan Province, and the areas that reach the overload limit in 2020 are mainly concentrated in the north and west of the Loess Plateau. Through the ecological construction in the past 20 years, the overall grass-livestock balance of the Loess Plateau is gradually improving, among which the improvement effect is obvious in Shaanxi and Shanxi provinces. In a moderate livestock carrying scenario, the livestock carrying intensity on the Loess Plateau is about 0.37SU/hm², and the income per hectare on the Loess Plateau is about 741.49 yuan.