Climate warming is more obvious in high-altitude mountains, and as a result, investigating the spatial patterns of mountainous vegetation responses to climate warming is becoming a new hot spot of mountain research. The Luliang Mountain Range lies on the east side of the Loess Plateau in central China and is characterized by an extremely fragile environment due to the lack of precipitation. Based on latitudinal gradients from north to south in the Luliang Mountain Range, the affiliated Guancen Mountain in its northern section, Guandi Mountain in its central section, and Wulu Mountain in its southern section were selected as study area. Each of these mountains was divided into three gradients: high altitude, medium altitude, and low altitude. The corresponding elevations for the high, medium, and low altitudes were 2571.3 m, 2395.0 m, and 2222.4 m for Guancen Mountain, 2179.1 m, 2000.7 m, and 1899.7 m for Guandi Mountain, and 1602.0 m, 1458.6 m, and 1318.0 m for Wulu Mountain, respectively. Three experimental plots heated by open-top chambers (OTCs) were placed within each altitudinal gradient. Treatments were implemented using completely randomized block design and including control (CK), low temperature increase (LW), and high temperature increase (HW). During the growing season in 2017, the growth characteristics and hydrothermal factors of the herbaceous communities in mountainous forests were surveyed in order to explore the responses of herbaceous communities to climate warming as well as the spatial pattern changes of these responses with latitudinal and altitudinal gradients. The results revealed the following under the LW and HW treatments: (1) air temperature increased by 0.47℃ and 1.00℃, respectively. The atmospheric relative humidity increased by 1.37% and 1.94%, respectively. The increasing amplitude of air temperature grew significantly with altitude (P = 0.012). (2) Corresponding soil moisture decreased by 0.32% and 0.64%, respectively. The soil temperature decreased by 0.07℃ and increased by 0.06℃. The increasing amplitude of soil temperature diminished significantly with latitude (P = 0.003). (3) The respective vegetation density increased by 41.27 plants/m² and 78.53 plants/m², but vegetation height increased by 0.04 m and 0.03 m. The vegetation frequency increased by 5.47% and 3.47%, while vegetation coverage significantly increased by 5.32% and 0.88% (P = 0.042). (4) The relationships among vegetation indices, temperature factors, and moisture factors using RDA ordination analysis indicated that the absolute value of the correlation coefficient between vegetation and temperature increased by 31.49% and 56.82%, as well as that between vegetation and moisture correspondingly increased by 38.67% and 62.89%, respectively. Therefore, in the Luliang Mountain Range, temperature factors were more responsive to warming, with air temperature being positively correlated with altitude and soil temperature being negatively correlated with latitude. However, the warming effects from the OTCs strengthened the relationship between vegetation and moisture, which promoted the dependence of plants on moisture, thereby significantly affecting vegetation coverage. Warming should be controlled in terms of amplitude, which will then have positive effects on vegetation. When precipitation occurred during the experiment, however, the associated moisture enhancement could weaken the warming effects on the soil. Thus the soil temperature decreased during warming treatments, indicating that precipitation had a greater influence on warming effects in regions where precipitation dominated the environmental factors. Therefore, the effects of short-term warming were affected largely by rainfall, which introduced errors into the results. We strongly suggest that the experimental duration should be prolonged in similar studies on warming effects in order to reduce these errors.