The office is a great place to collaborate, communicate, and work productively--most of the time. If given a bad environment or during a particularly stressful period, the workplace can quickly turn hostile, making employees stressed-out, unproductive, and even resentful of their employer. Bad moods and stress are contagious, so it's especially important to nip these feelings early.

While you can't do much about workloads and the demands of the job, you can make minor changes to your office that lead to significant boosts in mood and productivity for your employees. Try these seven simple changes and watch as your employees become happier and more productive:

1. Introduce plants. Put some plants in the office. Some studies suggest that plants help people focus and concentrate on their work, leading to higher overall productivity. Even better, colorful plants help liven up your office's personality, leading to a calmer, more welcoming environment. They serve as a reminder of the natural world--what's outside the office's walls--and aren't hard to maintain. They're certainly easier on the eyes than a sterile white wall or boring office furniture.

2. Offer healthy snacks. Many offices offer coffee to their employees, but why not offer some healthy snacks as well? Fruits, vegetables, and nuts are great examples--full of complex carbohydrates or protein, these snacks provide a great midday boost to the brain, improving both mood and productivity. If you make them easily available, your workers will be more likely to indulge--and they'll even appreciate them as an added benefit of the workplace.

3. Waft scents throughout the office. While the science behind aromatherapy is questionable, there are certain scents that help people concentrate and relax, both of which are crucial elements of a healthy, thriving workplace. Use candles, incense, or other aroma dispersers to spread positive scents throughout the office. For example, lemon is supposed to have a calming effect, and lavender is supposed to ease emotional stress. Cinnamon and peppermint are other popular scents for focus and relaxation.

4. Let your employees listen to music. Background music at a moderate volume is shown to improve concentration. There isn't a specific type of music that works better than others, but personal fondness for the music playing can positively influence this effect. Let your employees listen to music while they work, or use crowdsourced playlists or rotate who is in charge of the music selection each day to make sure everyone stays happy with it.

5. Emphasize the good. Remind your employees of all the good things about the job by distributing reminders of them throughout the office. Have a spot for an "employee of the month" (or something similar) that recognizes individuals. Mark progress toward your goals. Hang pictures of past gatherings and employee events.

6. Encourage socialization. The workplace is a lot friendlier and more welcoming when everyone knows each other, at least a little bit. Encourage open conversations between your employees however you can (and there are a ton of ways to do this). For example, you could buy lunch for the group once a month and stimulate discussion within the group. You could encourage taking water cooler or coffee breaks. You could tear down the walls to make the office more personable. You could even lead the charge yourself by opening friendly conversations with your employees or co-workers.

7. Make the office fun. Allow your employees to have a little fun in the office. It can help break up the stress or monotony of bad days, and serves as a perfect decompression exercise when your employees feel like they're at their limit. You don't have to go as far as installing a pool table or a dartboard in the break room (though you certainly could), but do take some effort to make the office a livelier, more fun place.

No matter how much you change your office, your employees will always suffer from occasional bad moods and bouts of low productivity. Try not to sweat it. Make the office changes you can to make the environment a happier, healthier place to work, and your team will be grateful.